Environmental Science & Policy 2 (1999) 9±24
Acid deposition and its e€ects in China: an overview
Thorjùrn Larssen a, *, Hans Martin Seip a, 1, Arne Semb b, 2, Jan Mulder c, 3,
Ivar P. Muniz d, 4, Rolf D. Vogt a, 5, Espen Lydersen e, 6, Valter Angell f, 7,
Tang Dagang g, 8, Odd Eilertsen d, 9
a
Department of Chemistry, University of Oslo, P.O. Box 1033, Blindern, 0315 Oslo, Norway
b
Norwegian Institute for Air Research, P.O. Box 100, 2007 Kjeller, Norway
c
Department of Soil and Water Sciences, Agricultural University of Norway, P.O. Box 5028, 1432 AÊs, Norway
d
Norwegian Institute for Nature Research, P.O. Box 736, Sentrum, 0105 Oslo, Norway
e
Norwegian Institute for Water Research, P.O. Box 173, KjelsaÊs, 0411 Oslo, Norway
f
Norwegian Institute of International A€airs, P.O. Box 8159, Dep. 0033 Oslo, Norway
g
Atmospheric Environment Institute, China Research Academy of Environmental Science (CRAES), Beiyuan,
Beijing 100012, People's Republic of China
Abstract
Acid rain is an increasing environmental problem in China. At present SO2 emission is about 20±22 million tons. However
with a growing number of large power plants the long-range transport of air pollutants is expected to increase. The highest acid
deposition is near the emission sources. Wind-blown, alkaline soil dust is important in neutralizing the acidity of the emissions,
especially in large parts of northern China. In the south, where alkaline soil dust contributes less to acid neutralization, the
annual pH in precipitation was below 4.5 at monitoring stations in several provinces and as low as 4.1 in some urban areas.
Total sulfur deposition has been estimated to be about 10 g S mÿ2 year ÿ 1 in heavily exposed areas. Negative e€ects on forests,
including die-back, have been reported for relatively small areas near large cities. Since large, regional surveys have not been
carried out, there are large uncertainties about e€ects on a regional level. The high concentrations of gaseous pollutants,
especially within and near the cities, are likely to have severe e€ects on human health as well as on materials and vegetation.
Several ®eld and laboratory studies, as well as computer simulations, indicate that acidi®cation of soil and soil water has
occurred in the past few decades. This has probably caused elevated concentrations of toxic aluminum in soil water. At present,
the toxic e€ect of Al is likely to be counteracted by high concentrations of calcium at many places. The Chinese authorities have
recognized air pollution and acid rain as serious environmental problems, however, there are diculties in implementing e€ective
measures to reduce the problems. With respect to ecological e€ects we lack a comprehensive regional overview of the extent of
the acid deposition problem in China. Such information is necessary before e€ective countermeasures can be developed. # 1999
Elsevier Science Ltd. All rights reserved.
Keywords: Acid rain; Air pollution; Acidi®cation; Ecosystem e€ects; China; Soil; Water
* Corresponding author. Tel.: +47-22-855-659; fax: +47-22-855441; e-mail: [email protected].
1
E-mail: [email protected]
2
E-mail: [email protected]
3
E-mail: [email protected]
4
E-mail: [email protected]
5
E-mail: [email protected]
6
E-mail: [email protected]
7
E-mail: [email protected]
8
E-mail: [email protected]
9
E-mail: [email protected]
1. Introduction
Acid deposition was recognized as a potential environmental problem in China in the late 1970s and
early 1980s (Zhao and Sun, 1986; Zhao et al., 1988;
Wang et al., 1996, 1997a). The First National
Symposium on Acid Rain was convened in November
1981. In 1982 the National Environmental Protection
Agency (NEPA) organized and sponsored the National
1462-9011/99 $ - see front matter # 1999 Elsevier Science Ltd. All rights reserved.
PII: S 1 4 6 2 - 9 0 1 1 ( 9 8 ) 0 0 0 4 3 - 4
10
T. Larssen et al. / Environmental Science & Policy 2 (1999) 9±24
Survey of Acid Rain, in addition to local research projects in several provinces (Zhao et al., 1988). Based on
the ®ndings of the ®rst survey, the Second National
Survey on Acid Rain was initiated in 1985 and lasted
for two years; the third national acid rain research
project lasted from 1986 to 1990 (the 7th ®ve-year
plan) and the fourth national project from 1991 to
1995 (the 8th ®ve-year plan) (Wang et al., 1997a). The
two ®rst projects focused mainly on emission of SO2
and distribution and deposition of acid rain, while the
two subsequent projects also involved studies of
e€ects.
China's energy consumption increased 5.3%
annually over the period 1980±1991 (Byrne et al.,
1996). Coal accounted for more than 34 of the commercial energy production and it is likely that coal will
remain the major energy carrier in the next decades.
The SO2 emissions have recently shown a lower
growth rate than in previous years due to cleaner technology on new power plants and boilers and legal provisions. Ocial plans aim at stabilizing the emissions
at about present values (NEPA, 1997), but other scenarios suggest that the Chinese SO2 emissions will continue to increase. A considerable increase is expected
in the NOx emission due to the fast increasing number
of motor vehicles. Hence, acid deposition in China is
likely to become more serious in large areas (Rodhe
et al., 1992; Seip et al., 1995; Foell et al., 1995).
Preliminary calculations, e.g. by the RAINS-Asia
model (Downing et al., 1997), suggest that the critical
loads of forest ecosystems are seriously exceeded in
many areas (Hettelingh et al., 1995). However, as will
be discussed later, no thorough studies of critical loads
have been carried out for Chinese conditions and the
values are highly uncertain.
The combination of high emissions of acid gases
and acid sensitive ecosystems requires a better
understanding of the relationship between emissions
and environmental e€ects than what is available
today.
Here we give an overview of the current knowledge
related to acid rain in China. The focus is on emissions
of acidifying and acid-neutralizing substances and on
deposition and e€ects of acid rain. We concentrate on
ecosystem e€ects rather than e€ects on health and materials because the latter two are largely local e€ects,
particularly health e€ects which are primarily caused
by the acid rain precursor SO2 (and particles) rather
than the acidity of rain.
2. Emissions
Estimated total SO2 emissions in China vary from
16 to 22 million tons per year (see e.g. Cao, 1989;
Akimoto and Narita, 1994; Wang et al., 1996;
Arndt et al., 1997). The ocial ®gure for 1995 is
019 million tons SO2, while the RAINS-Asia model
used 22 million tons for 1990 (Wang et al., 1996).
The di€erences in the emission ®gures may be
partly due to di€erent average sulfur content of
coal used in the calculations (Akimoto and Narita,
1994) and partly to exclusion of small domestic
sources in the ocial ®gures (Wang et al., 1996).
The annual total SO2 emission has been increasing
the last decades (Fig. 1) and is likely to increase
further in the near future. The average sulfur content of the coal consumed is 1.2%, but in Guizhou
and Sichuan provinces the averages are 3.2 and
2.8%, respectively.
Fig. 1. Sulfur emission in China from 1982 to 1995 (Statistics China, 1983±1996).
T. Larssen et al. / Environmental Science & Policy 2 (1999) 9±24
The nitrogen emissions in China are dominated by
NH3 from fertilizer and domestic animal waste (Zhao
and Wang, 1994; Galloway et al., 1996). Commercial
fertilizers account for about 80% of China's total 20
Tg N year ÿ 1 ¯ux to the atmosphere. The nitrogen mobilization is expected to increase signi®cantly in the
coming decades due to increased use of fertilizers as
well as enhanced fossil fuel combustion (Galloway
et al., 1996).
3. Geographical distribution
According to Zhao and Sun (1986), two core areas
for acid rain were identi®ed in the beginning of the
1980s: the Chongqing-Guiyang and the Nanchang core
zones (Fig. 2). In the beginning of the 1990s two more
core zones were observed: one in the southeast coastal
area (Fuzhou±Xiamen±Shanghai) and one in the
coastal north area surrounding Qingdao in Shandong
Province (Wang et al., 1996).
11
4. Atmospheric dispersion and deposition
4.1. Atmospheric concentrations of SO2
Monitoring of SO2 in 88 Chinese cities in 1994
showed that annual average concentrations varied
from 2 to 472 mg/m3 (Wang et al., 1996). Average
concentrations were 89 mg/m3 in northern cities and
83 mg/m3 in southern cities. Forty-eight of the 88 cities
exceeded the Chinese National Air Quality Standard
Class II (60 mg/m3 annual avg.) for SO2 (Wang et al.,
1996). High SO2 concentrations are observed in both
southern and northern China, while acid rain is mainly
observed in the south. SO2 concentrations in Chinese
cities, from di€erent sources, are given in Table 1.
4.2. Measurements and monitoring of precipitation
chemistry
In the 1980s, most of the acid rain research was
focused on the situation in the Sichuan, Guizhou,
Guangxi and Guangdong provinces, and information
Fig. 2. Map of the People's Republic of China.
12
T. Larssen et al. / Environmental Science & Policy 2 (1999) 9±24
Table 1
Concentrations of SO2 and total suspended particles (TSP) in air at di€erent sites in China
Place
SO2
concentration
(mg/m3)
TSP
(mg/m3)
Average
period
Year
measured
No. of measure
sites included
Reference
Northern
Southern
Beijing
Chengdu., urban
Chongq., Jiulongpo district
Chongq., Ba county
Chongq., Dadukou district
Chongq., Jiangbei district
Chongq., Nanan district
Chongq., Nanshan park
Chongq., Nanshan, Huangshan
Chongq., Nanshan, Tieliao
Chongq., Nanshan, Wenfongtai
Chongq., Nanshan, Wenfongtai
Chongq., Nanshan, Zhenwushan
Chongq., Shizhong district
Chongq., Simian shan
Chongq., Simian shan
Chongqing
Chongqing, Nanshan park
Chongqing, Nanshan park
Chongqing, Nanshan, Zhenwushan
Chongqing, Nanshan, Zhenwushan
Chongqing, suburb 1
Chongqing, suburb 2
Chongqing, urban
Guangzhou
Guangzhou
Guiyang
Guiyang
Guiyang catchment
Guiyang, suburb 1
Guiyang, suburb 2
Guiyang, urban
Guiyang, urban
Huhot
Qingdao
Qingdao
Shanghai
Shenyang
Xian
110
100
115
85
280
240
320
400
310
50
130
450
133
254
400
540
5
8
422
40
100
126
214
138
27
402
90
47
504
356
44
40
48
157
423
119
470
233
85
152
47
740
444
380
658
24 h
24 h
1 year
annual
annual
annual
annual
annual
annual
1 month
1 month
1 month
24 h
24 h
1 month
annual
annual
annual
annual
24 h
24 h
24 h
24 h
annual
annual
annual
annual
annual
winter season
annual
1 month
annual
annual
1 month
annual
winter season
winter season
annual
1 year
1 year
1 year
1985
1985
1991
1985±1989
1990
1990
1990
1988±1989
1990
Jan. 1989
Jan. 1989
Jan. 1989
Sept 1986
July 1988
Jan. 1989
1990
1985±1989
1989±1990
1990
Sept 1986
July 1988
Sept 1986
July 1988
1985±1989
1985±1989
1985±1989
1988
1991
1990
1990
1993
1985±1989
1985±1989
1993
1985±1989
1990
1990
1990
1991
1991
1991
31
33
1
1
?
?
?
?
?
1
1
1
1
1
1
?
1
1
?
1
1
1
1
1
1
1
?
1
6
?
1
1
1
1
1
5
4
?
1
1
1
Cao, 1989
Cao, 1989
Wells et al., 1994
Lei et al., 1997
Ma, 1990
Ma, 1990
Ma, 1990
Ma, 1990
Ma, 1990
Ma, 1990
Ma, 1990
Ma, 1990
Bian and Yu, 1992
Bian and Yu, 1992
Ma, 1990
Ma, 1990
Lei et al., 1997
Ma, 1990
Zhao et al., 1995b
Bian and Yu, 1992
Bian and Yu, 1992
Bian and Yu, 1992
Bian and Yu, 1992
Lei et al., 1997
Lei et al., 1997
Lei et al., 1997
Cao, 1991
Wells et al., 1994
UNDP, 1991
Zhao et al., 1995b
Larssen et al., 1998
Lei et al., 1997
Lei et al., 1997
Larssen et al., 1998
Lei et al., 1997
UNDP, 1991
UNDP, 1991
Zhao et al., 1995b
Wells et al., 1994
Wells et al., 1994
Wells et al., 1994
100
500
300
690
180
496
500
300
970
375
335
220
380
510
on precipitation chemistry are available from several
sources (e.g. Zhao and Sun, 1986; Zhao et al., 1988;
Zhao and Xiong, 1988; Zhao and Zhang, 1990; Qi and
Wang, 1990; Xue and Schnoor, 1994; Zhang et al.,
1996; Wang et al., 1997a). In the beginning of the
1990s, the National Acid Deposition Monitoring
Network (NADMN) was established, with the purpose
of increasing the knowledge about acid deposition in
other provinces than those in the south and southwest,
especially in the southeast.
In general, sulfate is the dominating anion in precipitation and calcium and/or ammonium are the
dominant cations (Table 2). The pH is relatively low,
with weighted averages less than 4.5 in several pro-
vinces. The acid rain situation in Chongqing and
Guiyang has been and still is particularly serious, with
a volume-weighted average pH of about 4.1 in the
urban areas. However, it is likely that the situation has
been improved recently in Guiyang, due to countermeasures induced by the local government (Lydersen
et al., 1997). The information on acid deposition in
rural areas is relatively scarce since little monitoring
data are available.
Some data are available from rural areas near
Chongqing and Guiyang and a decrease in total ion
concentration out from the urban areas can been be
seen (Fig. 3). This clear trend can be explained by the
high emission from small, domestic sources inside the
207
204
0.71
4.58
26.3
50.6
87.7
29.4
5.9
7.0
167
15.9
21.1
1982±1984
351
318
4.97
488
440
5.11
4.07
84.5
78.9
231.2
56.5
10.1
26.4
411
21.0
8.2
4.42
37.9
49.2
198
44.6
11.2
10.5
281
25.3
11.8
1992±1995
1175
4.43
37.2
23.9
125.3
26.6
6.7
6.0
188
15.2
10.1
4.8
226
218
1.7
1982±1984
1982±1984
229
207
5.2
4.44
36.3
64.1
42.0
18.3
45.4
23.4
165
18.0
23.9
1987±1989
1200
4.33
47
116
74
15
22
17
200
20
21
33
291
274
3.0
1982±1984
From Wang et al. (1997a), bFrom Zhao et al. (1988), cFrom Zhao et al. (1994), dFrom Larssen et al. (1998).
a
395
354
5.6
4.14
72.4
106
110
48.3
51.4
7.4
307
31.6
15.0
1987±1989
700
4.11
77
123
125
31
17
17
299
23
30
35
390
387
0.4
1982±1984
1992±1993
597
6.10
0.8
52.4
167.6
52.9
41.4
28.0
161
22.6
91.4
21.5
343
297
7.2
1992±1993
1212
5.48
3.3
60.2
116.7
14.0
29.6
8.9
166
20.9
28.0
10.7
232
226
1.5
1992±1993
1020
5.37
4.3
58.5
65.2
8.6
18.6
10.8
107
21.4
24.4
1.0
166
154
3.9
1992±1993
1550
4.69
20.5
68.5
49.3
9.6
24.5
8.4
110
18.0
20.3
8.3
180
156
7.3
1992±1993
1274
4.78
16.6
81.7
63.0
10.1
8.9
7.8
128
18.1
16.3
11.7
188
174
3.8
Period
Rainfall (mm)
pH
H+
NH4+
Ca2+
Mg2+
Na +
K+
SO2ÿ
4
NO3ÿ
ÿ
Cl
Fÿ
a cations
a anions
anion de®ciency (%)
1992±1993
1379
4.48
33.2
70.1
52.3
7.3
14.8
5.1
104
14.0
19.3
11.0
182
149
10.2
1992±1993
1555
4.49
32.4
51.3
64.5
11.5
22.5
10.42
100
19.6
14.9
16.4
192
151
12.0
1992±1993
1108
4.47
34.0
100.5
64.8
9.5
8.9
7.3
129
22.4
16.4
3.2
225
171
13.5
Chongqingb
urban
Shangdonga
average
Jiangsua
average
Anhuia
average
Hubeia
average
Zhejianga
average
Hunana
average
Jiangxia
average
Fujiana
average
Table 2
Volume weighted annual average concentrations of ions in precipitation in China (concentrations in meq/l)
Chongqingc
urban
Chongqingb
rural
Chongqingc
rural
Guiyangb
urban
Guiyangb
suburban
Guiyangd
suburban
Guiyangb
rural
T. Larssen et al. / Environmental Science & Policy 2 (1999) 9±24
13
city centers, with large emissions of both SO2 and
dust. A study on fog chemistry was conducted at the
top of Emei mountain (3099 m above sea level, 300 km
west of Chongqing) in Sichuan in 1980; the average
pH was 4.64, with a minimum of 3.77, maybe due to
long range transport (Wang et al., 1991). Some model
studies indicate the level of air pollution in rural areas
and the degree of long range transport: Meng et al.
(1996) and Meng et al. (1997) combined use of a simpli®ed three-dimensional Eulerian model and a
Lagrangian trajectory model to study the transport
and deposition of sulfur in the Minnan area in Fujian
province. They concluded that long range transport
(i.e. from sources outside Fujian province), accounted
for almost 60% of the total sulfur deposition.
In most parts of northern China, the pH of precipitation is generally above 6, due to the high levels of
neutralizing soil dust in the atmosphere (e.g. Zhao
et al., 1988; Wang et al., 1997b). Hence acid rain is
probably not an important problem in this area.
However, direct e€ects from acid gases (and particles)
may be of great importance to both human health and
vegetation.
The composition of the rain samples from China differs from the composition of precipitation in Europe
mainly in that the concentrations of calcium relative to
sulfate are very high, and the concentrations of nitrate
relative to the other components are low. However,
nitrate is expected to become increasingly important as
the emissions from motor vehicles increase rapidly.
Possible e€ects of the large emissions of ammonia
have not been studied in detail in China. However,
these emissions are of importance, through neutralizing
acidity of the rain, but causing acidi®cation of soils
after deposition due to nitri®cation.
Also the concentration of ¯uoride in precipitation
appears to be high in China, e.g. mean values of 0.5±
0.7 mg/L in precipitation in Chongqing was reported
(Zhao et al., 1994; Lei et al., 1997). This may be linked
to combustion of coal with high ¯uoride contents, but
also to production of brick and tiles from clay with
high ¯uoride contents. Emissions are primarily as
hydrogen ¯uoride (HF), which is very toxic to plants.
4.3. Dust and particles in the atmosphere
Wind-blown soil dust is an important feature in the
Chinese atmosphere (Chang et al., 1996). In addition,
there are high concentrations of anthropogenically derived aerosol particles. Based on the work of Wang
et al. (1981), Zhao et al. (1988) suggested that the
ratio of dust derived from coal burning to that derived
from soils is about 2:1 in southern China and between
2:3 and 3:2 in northern China. Zhao et al. (1994) estimated 40% of the dust in Chongqing to originate
from coal burning, however, the authors pointed out
14
T. Larssen et al. / Environmental Science & Policy 2 (1999) 9±24
Fig. 3. Spatial trend in precipitation chemistry from the city center to rural areas for the cities Chongqing and Guiyang. Sodium, potassium and
¯uoride concentrations were small and are neglected in the ®gure for simplicity.
that the estimate was uncertain. Shao et al. (1995)
found that 50% of the particles in Beijing originated
from soils: soils were important source for metal ions,
while local combustion was the dominating source for
carbon in particles. In accordance with Shao et al.
(1995), Wang and Wang (1996) suggested that generally 30±70% of the particulate matter in urban areas
originate from soils. Several authors have discussed the
long-range transport of dust from the northern
Chinese deserts to Korea, Japan and the South China
Sea, which in parts of the year, especially the spring,
may be considerable (e.g. Suzuki et al., 1993;
Hashimoto et al., 1994; Chang et al., 1996).
The airborne anthropogenically derived particles are
generally smaller than the soil dust particles (Ning et
al., 1996; Yin et al., 1996). Ning et al. (1996) compared
the size of aerosol particles in a rural area (outside
Shenyang) with urban areas in cities in northern China
(Beijing, Shenyang, Lanzhou and Taiyuan). At the
rural site, most of the particles had an aerodynamic diameter larger than 10 mm, in the cities, a large fraction
was particles smaller than 10 mm. They also found the
pH and Ca2+ content of the particles to decrease and
SO2ÿ
and NH4+ content to increase with decreasing
4
particle size. In northern China the content of base
cations in airborne soil particles is considerably larger
than in southern China. According to Wang and
Wang (1996) the contents of calcium and sodium are,
respectively, about 3 and 1.5% in the north and about
0.1 and 0.5% in the south.
Yin et al. (1996) compared the chemical composition
of the aerosol particles in Beijing, Chongqing and
Guiyang. As can be seen from Table 3, the pH of the
particles dissolved in water was much lower in
Chongqing and Guiyang than in Beijing, while the
base cation concentration, particularly Ca2+, was
higher in Beijing. The sulfur content was high all three
places, though there are pronounced temporal variations. These results clearly show that the atmospheric
particles in northern China have a large ability to neutralize acid rain, compared to the situation in the
southwest. To what extent aerosols in the southwest
have an alkalizing e€ect on the precipitation is not
clear, although, Liu and Huang (1993) showed that in
Chongqing the aerosols have some neutralizing e€ect
on the precipitation. However, it is not clear in what
forms Ca2+ is bound in the particles, e.g. as nonneutralizing CaSO4 or as neutralizing CaO, CaCO3
(Chang et al., 1996). In addition to the possible neutralizing e€ect of the aerosol particles, the particle surfaces also play an important role in sulfate and nitrate
formation (Chang et al., 1996).
Table 3
Content of sulfur (S), potassium (K) and calcium (Ca) (in percent,
based on mass) and pH in aerosol particles dissolved in water (from
Yin et al., 1996)
Element
Chongqing
Guiyang
Beijing
S(March)
S(Sept.)
K
Ca
pH
4.2
2.2
0.7
1.3
4.1
2.8
0.8
0.3
1
4.3
3.2
4.5
1
4
6.8
T. Larssen et al. / Environmental Science & Policy 2 (1999) 9±24
4.4. Evaluation of the monitoring
The acid rain monitoring in China was evaluated by
an expert group at the Fourth Expert Meeting on Acid
Deposition and Monitoring Network in East Asia in
February, 1997 (EMAD, 1997). The expert group concluded that it is necessary to further optimize the acid
rain monitoring network in China and that there currently are some gaps between the state's needs and the
actual situation. As the weakest points in the present
monitoring network they identi®ed the use of nonstate-of-the-art technology, unsatisfactory regional
representativity of the selected sites, lack of data from
background stations, measurement of too few parameters and the quality assurance. They concluded
that the ®nancial support to acid rain monitoring was
too low and should be increased.
Variable quality of chemical analyses of monitoring
samples has also been pointed out by Larssen et al.
(1998) and Lydersen et al. (1997); a problem which
should be followed up in the future.
Ions transported as particles, especially calcium in
the Chinese atmosphere, may in¯uence strongly the
precipitation samples; the contribution depends on the
location of the collection site and the sampling procedures. In cities and industrial areas with emissions of
dust and particles, settling of coarse particles may be
considerable. It is therefore important to assess carefully what deposition is collected and the in¯uence of
particulate deposition. To get better knowledge about
long-range transport of both pollutants and natural
dust, more monitoring stations in rural areas are important.
5. Studies of e€ects on ecosystems
5.1. Forest
Damages to forests may be due to direct e€ects of
the acid rain precursors SO2 and NOx, or to indirect
e€ects involving soil acidi®cation and mobilization of
toxic metals as aluminum. Events with extremely acidic
rain may also cause direct damages of leave surfaces.
Most research on forest damage in China has been related to direct e€ects from SO2, acid mist or extremely
acid rain events.
Forest decline in large areas has up to now not been
reported in China (Bian and Yu, 1992). However, forest decline in smaller areas, particularly near cities and
industrial areas is observed. In the early 1980s serious
forest damage was observed on Nanshan mountain,
just outside Chongqing city. More than 50% of a
1800-ha Masson pine (Pinus massoniana) stand died
(Wang et al., 1996). Several researchers have discussed
the reason for the forest decline (e.g. Liu and Du,
15
1991; Bian and Yu, 1992; Totsuka et al., 1994).
Important factors are considered to be high concentrations of SO2 and hydrogen ¯uoride (HF), acid rain
and attacks by insects and fungi. Several di€erent
symptoms were observed on trees, as tip necrosis of
needles, reduced needle length, premature abscission,
crown thinning, branch die-back and reduced radial
growth. Bian and Yu (1992) investigated three sites
with di€erent pollution loading at Nanshan. They
found good correlations between the air concentration
of SO2, the sulfur content of the needles and the extent
of damage. However, even better correlation was
found between ¯uorine content in needles and damage.
Unfortunately the HF concentration in air was not
determined. Di€erences in soil properties at sites with
healthy and damaged pine were not observed; on this
basis Bian and Yu (1992) concluded that direct e€ects
from the gases and not acidi®cation of soils were important for the observed damage. Other scientists
believe that soil acidi®cation has been of major importance (Ma, 1990). The ®nal die-back of the trees is
believed to be caused by insect pests (Bian and Yu,
1992).
Regarding the discussions about the causes of the
Nanshan forest decline, Totsuka et al. (1994) compared the conditions of Masson pine and camphor tree
at one heavily polluted and one lightly polluted area
outside Chongqing. They also conducted laboratory
experiments to clarify interactive e€ects of SO2 and
soil acidi®cation on tree growth. They found a slower
growth with high SO2 concentration and acid soil, but
they did not try to generalize the observations e.g. in
terms of dose±response relationships.
Cao et al. (1988) and Wang et al. (1988) discussed
the relationship between acid precipitation and decline
of ®r at high elevations at Emei mountain and conclude that acid rain and acid fog may result in both
direct and indirect e€ects.
A forest damage assessment study was carried out in
Liuzhou, Guangxi province (Wang et al., 1996). Of
436 tree species investigated, 84 were a€ected; 30 of
these seriously. P. massoniana and Cinnamonum burmannii were the two most heavily damaged tree
species. Wang et al. (1996) did not discuss the relationship between the observed damages and the pollution
types and levels.
According to Wang et al. (1996) 32% (280,000 ha)
of the forested area in Sichuan province (including
Chongqing) is in¯uenced by air pollutants and acid
rain. In Guizhou province, 15,000 ha are in¯uenced.
Loss of Masson pine was estimated from results showing di€erences in growth in supposedly clean and polluted areas in 11 Chinese provinces. The annual
growth rate in acidi®ed areas was found to be 40±50%
relative to rural, supposedly nonacidi®ed, areas (Wang
et al., 1996).
16
T. Larssen et al. / Environmental Science & Policy 2 (1999) 9±24
Cao (1991) and Shu et al. (1993) presented a multiple regression equation for yield loss of coniferous
trees as a function of rain pH, SO2 concentration and
soil depth. They did not report details about model
development and did not discuss uncertainties, which
obviously are large.
5.2. Crops
E€ects of SO2 and HF on crops have been studied
in China since the 1970s (Cao, 1989). Cao (1989)
reported short-term exposure concentrations of SO2
and HF causing 5% injury to three sensitivity groups
of crops. The sensitive species are reported to have a
5% injury at 880±1430 mg/m3 SO2 and 12±48 mg/m3
HF during 8 h exposure (Cao, 1989). How the injury
was measured was not reported. Dose±response curves
for yield loss caused by SO2 were given for short-term
exposure, the investigated plants have decreasing sensitivity as follows (Cao, 1989):
cabbage > pinto bean > potato > wheat > soybean
> corn > rice
For long-term exposure of SO2, a yield loss of 5% is
reported for 30±50 mg/m3 SO2 for sensitive species
(potato, bean, Chinese cabbage). In the most polluted
Chinese cities a yield loss of 5±25% should be
expected for the most common crops (Cao, 1989).
Chang and Hu (1996) reported that the average yield
reduction for vegetables in Chongqing is 24.4%. Also
Cao (1989) studied e€ects of both SO2 and acid rain in
open top chambers. Rice was among the most resistant
species both to SO2, acid rain and the combination of
the two. `Most vegetables' were classi®ed as sensitive.
A ranking of the sensitivity of acid rain for the most
common crops in China is also given by Wang et al.
(1996)
rape > wheat > corn > barley > soybean > rice
> tobacco > jute
Of the most common vegetables, tomato, eggplant and
cucumber are among the most sensitive, while cabbage,
spinach and carrot are among the least sensitive to
acid rain (Wang et al., 1996). The sensitivity ranking
from Cao (1989) and from Wang et al. (1996) are
rather di€erent. It is not clear if the discrepancies are
due to di€erences between SO2 and acid rain e€ects,
or if they are due to experimental uncertainties. In
none of the above-mentioned studies, the e€ects have
been related to soil properties, which are of major
importance for the growth.
Chameides et al. (1994) estimated that 10±35% of
the World's grain producing areas, including the densely populated part of China, may be exposed to
ozone levels large enough to reduce crop yields. As
e€ects of SO2 and HF have been in focus, very little
research has been done on the e€ects of other gaseous
pollutants, as ozone and NOx, on vegetation in China.
5.3. Other natural vegetation
We have found very little information about possible
e€ects of air pollution and acid rain in China on vegetation other than crops and the most common tree
species. Studies of for example some wild herbs and
ferns collected for food, medicine and fodder and of
lichens or other indicator species particularly sensitive
to air pollution would be valuable.
6. Soils and soil water
Direct e€ects of air pollutants on vegetation are
most commonly used to explain damages in China.
However, changes in soils caused by acidi®cation are a
likely long-term e€ect of acid rain. Dai et al. (1997)
and Pan (1992) compared soil analyses conducted 30
years ago with recent results from several sites in
southern China. They found the soil pH to have
decreased considerably; between 0.1 and 1.0 pH units.
These results clearly suggest that soil acidi®cation has
occurred and may become a serious problem in China
in the future. This is in agreement with modeling
results (Zhao and Seip, 1991). However, experimental
and modeling studies involve relatively large uncertainties, particularly when used in large areas with low
spatial resolution. Furthermore acid deposition is not
the only possible cause of soil acidi®cation; for
example changes in vegetation type, ecosystem succession etc. may have similar e€ects (e.g. logging of
broad-leaved vegetation followed by planting of coniferous trees, as was the case in large areas of China in
the late 50s and early 60s). In addition, many of the
forests in China are intensively used, for example collection of mushrooms and herbs, as well as dead wood
and litter, are quite common.
Liao et al. (1997, 1998) conducted laboratory experiments in which forest soils from ®ve sites in southern
China (Chongqing, Guiyang, Fujian, Hunan and
Nanchang) were extracted with di€erent salt and acid
solutions. The experiments showed that severe depletion of soil base cations is likely to occur in the
most sensitive soils, if the acid deposition continues at
current level or increases. The soils from the Fujian
and Nanchang were found to be the most sensitive of
these soils. However, one must be careful in generalizing to larger geographical scales because of the heterogeneity of soils even within small geographical areas
(Larssen et al., 1998). To what extent e€ects on vegetation via soil acidi®cation may occur in the future
will depend strongly on the development of both the
T. Larssen et al. / Environmental Science & Policy 2 (1999) 9±24
sulfur and the base cation deposition. Lin et al. (1992)
studied the bu€ering capacity of soils from several
places in China. They concluded that soils from
Nanshan (outside of Chongqing) had low bu€ering capacity, the soils from Guiyang and Hunan were relatively well bu€ered, while the soils from Hebei and
Xian had the highest bu€er capacity. Such soil experiments give valuable information about the particular
soil sampled, but generalizations are dicult also here
due to large spatial variability.
Sulfate absorption in soils is a process which may
retard the acidi®cation process. Liao et al. (1994) studied this process in soils from Guiyang and Nanchang
in laboratory experiments and found that the sulfate
adsorption was relatively low (50±200 mg/kg) at sulfate concentrations corresponding to ambient sulfate
deposition. Larssen et al. (1998) estimated the sulfate
retention in a catchment outside Guiyang to be 30±
40% of the input.
Results from studies of soil water have been published from sites in Chongqing (Xu et al., 1994a) and
Guiyang (Larssen et al., 1998). In Chongqing, high
concentrations of sulfate (80±335 mg/l) and calcium
(10±51 mg/l) were found. However, concentrations of
aluminum were rather low (38±150 mg/l) (Xu et al.,
1994a). In the Guiyang study concentrations of all
these three components were high (SO2ÿ
4 : 18±111 mg/l,
Ca2+: 3±25 mg/l and Al3+: 0.4±13 mg/l) (Larssen et
al., 1998). The chemical composition of precipitation,
soil and soil water in the Guiyang catchment were
compared with several catchments in Poland and
Norway, showing that concentrations of sulfate, aluminum and calcium were especially high in Guiyang
(Larssen et al., 1996).
7. Surface water
Xue and Schnoor (1994) published results from a
survey of 16 streams and lakes in southwestern China.
All investigated waters had a pH above 6.5 and base
cation concentration above 300 meq/l, due to considerable acid neutralization in the soils and high deposition of alkaline dust. At high elevation, Xue and
Schnoor (1994) found some waters that may be sensitive to acidi®cation (ANC < 150 meq/l), but not acidi®ed at present. Williams et al. (1995) studied the ion
concentration in the UÈruÈmqi river in northwest China
and concluded that this river is not sensitive to acidi®cation. Larssen et al. (1998) reported rather low pH in
two small headwater streams outside Guiyang.
However, the water is rapidly neutralized downstream,
probably due to mixing with drainage water from
more alkaline soils. Based on this limited amount of
information surface water acidi®cation in China is considered to be a minor problem at present. Model stu-
17
dies by Zhao and Seip (1991) using the MAGIC model
(Cosby et al., 1985) also indicated that acidi®cation of
surface water is not likely to become a serious problem. However, one should be aware of possible future
acidi®cation in some sensitive areas. Lydersen et al.
(1997) identi®ed waterbodies with low acid neutralization capcity in mountainous areas in Guizhou and
Guangdong provinces. At present the deposition of
acidifying compounds is quite low. However, if the
present low loadings are replaced by higher inputs of
acid rain, surface water acidi®cation is likely.
There are very few studies on the ecological e€ects
of high acidity on Chinese freshwater ecosystems. Xia
et al. (1994) studied e€ects on freshwater biota in four
small ponds and two lakes in the Chongqing area and
concluded that the most acid ponds had higher transparency, fewer species of phytoplankton and lower
algal cell-density and biomass. Experimental evidence
suggested that low pH and low phosphorous levels
were limiting factors for these primary producers.
8. Integrated studies
In order to understand the acidi®cation processes in
one of the most exposed areas in China in more detail,
a small catchment outside Guiyang, dominated by yellow soil (Haplic Alisol in the FAO classi®cation system), was equipped for sampling of SO2 gas,
precipitation, throughfall, soil water and surface water
in 1992. The results from the ®rst years of sampling
are given in Larssen et al. (1998). The relatively low
pH in the precipitation (average 4.4) causes high concentration (1.6±4.6 mg/l) of inorganic aluminum in soil
water. However, possible toxic e€ects of aluminum are
probably counteracted by high concentration of base
cations, in particular calcium (8±19 mg/l), as pronounced e€ects on vegetation were not seen. The
authors concluded that the present high base cation
deposition seems to counteract potential e€ects to vegetation of elevated aluminum concentration in soil
water.
9. Critical loads
Critical load is often de®ned as ``the maximum input
of acid deposition to an ecosystem which will not
cause long-term damage to ecosystem structure and
function'' (Nilsson and Grennfelt, 1988). In the critical
load concept, toxic aluminum concentrations play a
key role. It is assumed that damage to biota occurs
above a threshold value for the molar Ca2+/Al3+
ratio in soil water. For forests in temporate and boreal
areas the critical Ca2+/Al3+ ratio at which tree
damage is expected, is assumed to be 1.0 (see e.g.
18
T. Larssen et al. / Environmental Science & Policy 2 (1999) 9±24
Cronan and Grigal, 1995). The scienti®c basis for setting absolute values for critical loads is weak and the
estimates are highly dependent on soil base cation
weathering rates and base cation deposition (e.g.
Lùkke et al., 1996). Nevertheless the concept of critical
loads is widely used in Europe and estimation of critical loads has also been performed for China. The critical loads for China at present are highly uncertain, as
estimates for weathering rates are based on soil pH
maps (with some adjustments for other factors). Also
the estimated rates of base cation deposition are not
well known. According to estimates done in the
RAINS-Asia project, the areas most sensitive to acid
deposition in China are, as expected, in the south
(Hettelingh et al., 1995; Downing et al., 1997). The
exceedances of the critical loads are largest in the
Chongqing-Guiyang area, but the values are also
exceeded in large areas in the south and south east
according to the RAINS-Asia model (Downing et al.,
1997).
Zhao et al. (1995a) made a critical load case study
for Guizhou province. Based on the same critical load
approximations and maps as used in RAINS-Asia,
large parts of the province were found to have a critical load of 200±500 eq/ha/year (approximately 0.3±0.8
g S m ÿ 2 year ÿ 1).
It is also uncertain if the critical Ca2+/Al3+ ratios
in temperate and boreal forests are relevant in China
as well. Gao and Cao (1989) conducted laboratory experiments in which aluminum toxicity to Masson pine
seedlings was related to ionic strength, pH and Ca2+/
Al3+ ratio. The results indicated that the aluminum
toxicity increased with decreasing pH and decreasing
ion strength and Ca2+-concentration. In another study
aluminum toxicity to Masson pine seedlings was related to biophysiological parameters and growth; the
growth was inhibited markedly at an aluminum concentration of 15 mg/l (Cao et al., 1992).
Traditional use of forests in China has been gathering of edible plants as well as collection of litter and
understory vegetation for use both as domestic fuel
and for fertilizing of cultivated land, usually after composting. This practice reduces the fertility of the forests
and increases the rate of soil acidi®cation because of
the removal of plant nutrients which would otherwise
be returned to the soil with the litterfall. This problem
has been addressed by scientists in the Dinghushan
biosphere reserve, who have conducted mass balance
studies of nutrients in litterfall and material removed
by local residents (Brown et al., 1995; Mo et al., 1995).
The removal of nutrients, particularly potassium and
calcium by harvesting and litter-collection, should also
be considered in connection with estimation of critical
loads.
10. E€ects on health
In discussing health e€ects the focus is not on acid
rain per se, but on the gaseous precursors (SO2, NOx)
or pollutants which to a large degree originate from
the same sources (e.g. particles).
WHO (1995) has given air quality guidelines for
Europe for some pollutants and for di€erent averaging
times. The maximum allowable annual average for
SO2 is 50 mg/m3 and for NO2 40±50 mg/m3. For particles WHO has decided not to give guidelines, since
there is no evident threshold for e€ects, while US EPA
recently proposed that daily average concentration of
particles with diameter less than 2.5 mm (PM2.5)
should not exceed 50 mg/m3 (Reichhardt, 1996).
Comparing with Table 1, it is clear that the SO2
guideline is exceeded in many places in China, the
exceedance may be up to eight times. In comparison,
NOx poses a minor problem at present, but NOx concentrations are increasing. The concentrations of airborne particles in many Chinese cities are very large
and accordingly serious health e€ects are expected.
A large number of epidemiological studies in Europe
and the USA have shown a signi®cant correlation
between level of air pollution and mortality. The correlation seems to be stronger between particles and mortality than between SO2 and mortality (Aunan, 1996).
In contrast, Wells et al. (1994) found the highest correlation between SO2 and mortality in Beijing and
Shenyang.
Concerning morbidity, there seems to be a clear
e€ect of air pollution on respiratory diseases. It is
highly probable that air pollution also may increase
the frequency of lung cancer, but quantitative relationships are dicult to obtain.
Studies in Western Europe and the USA generally
support a linear relationship between SO2 (or particles)
and health e€ects. There are indications that these
functions overstate the response in areas with high pollution levels (WHO, 1995); i.e. the dose±response function levels o€ as the pollution increases. Studies in
Beijing and Shenyang seem to support this conclusion
(Wells et al., 1994; Xu et al., 1994b).
In a World Bank study in Chongqing, air pollution
was found to be signi®cantly associated with daily
mortality from cardiovascular diseases and increased
frequency of hospital visits (Xu, 1996). The prevalence
of respiratory system illness in the downtown area of
Chongqing is very high being 34.3%, according to
Chang and Hu (1996). Pope and Xu (1993) found a
signi®cant, and nearly additive, e€ect of passive cigarette smoke and coal heating on respiratory symptoms
in a study in Anhui Province. Indoor pollution may be
particularly important as a cause of lung cancer in
many places in China (Xu et al., 1989).
T. Larssen et al. / Environmental Science & Policy 2 (1999) 9±24
11. E€ects on materials
The reactivity to various air pollutants varies greatly
for di€erent materials and pollutants. High concentrations of sulfur dioxide and high deposition acidity
cause increased corrosion of metals, and deterioration
of calcareous building materials, including concrete
and marble (see e.g. Kucera and Fitz, 1995).
Tsujino et al. (1995) compared corrosion rates for
di€erent materials in Shanghai and Chongqing in
China with rates at several Japanese cities and one
Korean city. Chongqing had the highest sulfur pollution load, followed by Shanghai. For all the materials investigated, the corrosion rates were
considerably larger in the Chinese cities than the
Japanese and Korean cities. The corrosion rates of
steel, copper and bronze were 3.9±4.5 times higher in
Chongqing than the average of the Japanese cities, for
marble the rate was 2.7 times higher in Chongqing. In
Shanghai, the metals corroded 1.5±2.5 times faster
than the Japanese average.
Wang et al. (1995) developed dose±response functions for material damage based on experiments at
di€erent levels of SO2 and pH in China. Chang and
Hu (1996) reported that life-times of outdoor painting
in Chongqing are only 12 to 13 of that found under background conditions.
Costs associated with material damage may be estimated from assessments of exposed material, and the
costs of early replacements or maintenance, e.g. painting. In many European cities, reduced sulfur dioxide
concentration levels have resulted in substantial reductions in building maintenance costs, and savings in
this sector are often comparable to the costs of reducing emissions (e.g. Kucera et al., 1993). Based on the
results referred to above, it is likely that this is also the
case in many Chinese cities.
12. Economic losses caused by acid rain and related
pollutants
Estimates of the economic losses from pollution may
be useful guidelines for environmental policy making
and may also draw attention to certain environmental
issues. Economic valuation of human life and natural
ecosystems is controversial, and large variations in estimated values will occur depending on the method
applied.
Cao (1989) estimated that 2.66 million ha crops are
a€ected by SO2 pollution and an area about half as
large by hydrogen ¯uoride pollution causing an economic loss of US$ 550 million annually. Cao et al.
(1990) estimated the yield loss of grain and vegetables
to be 2530 and 536 thousand tons in Guangxi and
Guangdong provinces. Based on a multiple regression
19
model they further estimated loss of timber to about 4
million tons in the same provinces. Shu et al. (1993)
estimated the annual cost of forest damage by acid
rain in Guangxi province to US$ 80 million. Ou et al.
(1996) estimated the economic loss due to acid rain
damages to crops and materials in the Xiamen area to
about US$ 6 million, which equal about 1% of the
gross product for the area. Chang and Hu (1996)
reported that the annual damage from air pollution in
Chongqing in 1993 was about US$ 220 million which
is 4.4% of the gross product. They included damages
to health, agriculture, forestry, materials and increased
transportation costs due to reduced visibility.
The World Bank (1997) has estimated the cost of
damages to crop, forest, ecosystems and materials
from acid rain in China to about US$ 5000 million
annually, corresponding to about 0.75% of the gross
domestic product (GDP). The World Bank (1997) also
estimated the costs of urban air pollution to health to
be almost 5% of GDP, based on a willingness-to-pay
approach. Due to methodological problems in valuation as well as lack of knowledge concerning actual
damages of various kinds, such estimates are highly
uncertain.
13. Policy issues
Coal will continue to be the major energy carrier in
China the next few decades (Xie and Kuby, 1997; Lin,
1998). The fast growth in rural and small town industries in China strongly a€ects the energy use and related pollution problems (Bradbury et al., 1996). If no
measures are taken to reduce the sulfur emissions, the
e€ects seen today are likely to increase to large areas
with impacts on health, natural ecosystems and crop
yields (Chang et al., 1998). Hence, the emissions must
be controlled, preferably reduced, from present levels;
this is also recognized by the Chinese authorities
(NEPA, 1997). In order to ®nd the best possible
measures against increased sulfur emissions and possible severe e€ects, important patterns in the energy
production and demand must be recognized: The
major coal producing regions are in the north while
the major coal consuming regions are in the south and
along the east coast. Hence coal must be transported,
and the transport system, i.e. the railway, has not sucient capacity, which is an important reason for energy
shortages (Xie and Kuby, 1997). Up to now, most
investments in the energy sector have been in new capacity development (US$ 93,000 million from 1985 to
1990) rather than energy conservation (US$ 5000
million) (Lin, 1998). China's total energy intensity
decreased with about 50% from 1980 to 1995, but at
about 1.8 coal equivalents consumed per US$ 1000 in
20
T. Larssen et al. / Environmental Science & Policy 2 (1999) 9±24
China it is still four times higher than in USA and 13
times higher than in Japan (World Bank, 1997).
The combination of high coal dependency, inadequate transportation capacity and low energy eciency suggests that energy conservation is a major key
for future energy planning even without taking into
account environmental e€ects. Hence an almost free
environmental bene®t can be achieved. Xie and Kuby
(1997) calculated that a 10% reduction in sulfur and
particle emission using coal washing can be reached at
a 2% increase in cost, without taking savings from
reduced pollutant levels into account. In estimating the
bene®t of measures it is important to consider all
major e€ects, i.e. locally on health and materials due
to reduced particle and SO2 concentrations, regionally
on crops, forests and waters and globally due to
reduced emissions of greenhouse gases (Working
Group on Public Health and Fossil Fuel Combustion,
1997; Aaheim et al., 1998). Strong sector barriers in
the present administrative system (cf. Lin, 1998) and
state-owned enterprises still protected by subsidies and
hence without a motive to save energy (cf. Xie and
Kuby, 1997), slow down the process of energy conservation and emission reduction.
The bureaucratic and administrative structure in
China is important in understanding some of the problems in implementing measures. National emission
standards and other regulations exist, but there seems
to be lack of power in the environmental protection
agencies in forcing implementation of adequate
measures (Lin, 1998). In many cases there is a con¯ict
between business interests and environmental protection in the administration. More clearly separated
business and government functions in energy supply
and demand may ease the enforcement of emission
standards (Xie and Kuby, 1997).
The direct in¯uence of the central power on the
local communities in China has decreased in recent
years, giving more responsibility to local governments
in enforcing environmental emission standards.
Therefore one must expect large di€erences in how
measures are implemented locally. There is also a
danger of polarization between town ocials and environmental protection agencies in small towns and
districts with economically important, but heavily polluting, small industries (Bradbury et al., 1996).
14. Conclusions
China's economy is rapidly developing and the
energy demand in the coming decades is likely to
increase substantially. There is little doubt that coal
will account for most of the increase since other energy
carriers will generally be more expensive in China.
Hence the sulfur emissions from coal combustion most
probably will continue to increase in the coming decades, even if several countermeasures are taken to
reduce the emission per energy unit produced. In this
situation it is important to present assessments of the
e€ects of acid rain as complete and detailed as possible.
This paper shows that considerable research on acid
rain and related issues has been carried out in China.
However, it is also clear that the available information
is incomplete and there still is a strong need for
increased knowledge within many ®elds of acid rain
and its e€ects. Major tasks for acid rain research in
China, all essential for choosing adequate countermeasures, include studies of many aspects of this environmental problem.
. The relationships between anthropogenic emissions,
natural emissions (particularly dust) and the chemical composition of precipitation should be better
understood. One important aspect is to expand the
focus from only pH and sulfate to also include the
other major components, as calcium, magnesium,
ammonium and nitrate. Another important aspect is
the transportation to, and deposition in, rural areas.
With an increasing tendency to move industry out
of the cities and building tall stacks, acid deposition
will most likely increase in more rural areas.
. Long-term changes in the soil chemistry is a serious
threat to forest-ecosystems and cropland. Little
qualitative information about soil acidi®cation is
available at present, which in turn means that estimates of future exceedances of critical loads are very
uncertain. Deposition of base cations is very important in mitigating soil acidi®cation in most areas in
China. Reduced emissions of alkaline dust may
therefore increase soil acidi®cation.
. A combination of regional surveys, integrated monitoring sites (including deposition, soils and soil
water), laboratory experiments with soils and modeling is necessary to make better predictions of future
soil acidi®cation.
. The critical load concept should be improved and
modi®ed to ®t Chinese ecosystems better. A few
well-designed and controlled experiments with a
selection of vegetation species should be carried out,
in addition to careful long-term monitoring of
changes on several ecosystem levels.
. Little is known about e€ects of long range transported air pollutants on forest and agro-ecosystems.
A systematic inventory of e€ects on forest ecosystems using standardized techniques should be carried
out at the national level.
. Water acidi®cation has up to now received less
attention and only been observed in very limited
areas. Although at this point in time not recognized
as a de®nite environmental problem, it may, given
T. Larssen et al. / Environmental Science & Policy 2 (1999) 9±24
acid loading in excess of neutralizing-bu€ering
capacity, become a problem in sensitive areas.
Identi®cation of biological indicators of early acidi®cation may here prove useful as prognostic tools. In
some areas with surface waters sensitive to acidi®cation, careful monitoring is recommended.
. Improving energy eciency will be very important
in e€orts to reduce emissions. In estimating net costs
of measures, all major e€ects on environment and
health should be considered.
Acknowledgements
We appreciate the assistance of several Chinese
scientists, in particular Senior Engineer Zhao Dawei,
Chongqing Institute of Environmental Science in
Chongqing, Dr. Xiong Jiling and Mr. Xiao Jinshong,
Guizhou Institute of Environmental Sciences in
Guiyang and Professor Zhou Guoyi, South China
Institute of Botany, Chinese Academy of Sciences,
Guangzhou. An earlier version of this manuscript was
prepared for the Environmental and Natural Resource
Division, Asia Technical Department, the World Bank
and The Norwegian Agency for Development
Cooperation as a part of the project Planning of an
Integrated Acidi®cation Study and Survey on Acid Rain
Impacts in China (PIAC).
References
Aaheim, H.A., Aunan, K., Seip, H.M., 1998. Climate change and local
pollution e€ects: an integrated approach. Mitigation and
Adaptation Strategies for Global Change, in press.
Akimoto, H., Narita, H., 1994. Distribution of SO2, NOx and CO2
emissions from fuel combustion and industrial activities in Asia
with 1818 resolution. Atmos. Environ. 28, 213±225.
Arndt, R.L., Carmichael, G.R., Streets, D.G., Bhatti, N., 1997. Sulfur
dioxide emissions and sectorial contributions to sulfur deposition in
Asia. Atmos. Environ. 31, 1553±1572.
Aunan, K., 1996. Exposure±response functions for health e€ects of air
pollutants based on epidemiological ®ndings. Risk Analysis 16, 693±
709.
Bian, Y.-M., Yu, S.-W., 1992. Forest decline in Nanshan. China. For.
Ecol. Manage. 51, 53±59.
Bradbury, I., Kirby, R., Shen, G., 1996. Development and environment: the case of rural industrialization and small-town growth in
China. Ambio 25, 204±209.
Brown, S., Lenart, M., Mo, J., Kong, G., 1995. Structure and organic
matter dynamics of a human-impacted pine forest in a MAB reserve
of subtropical China. Biotropica 27, 276±289.
Byrne, J., Shen, B., Li, X., 1996. The challenge of sustainability: balancing China's energy, economic and environmental goals. Energ.
Policy 24, 455±462.
Cao, H., 1989. Air pollution and its e€ects on plants in China. J. Appl.
Ecol. 26, 763±773.
Cao, H., 1991. Study on Economic Loss of Crops and Forest
Productivity caused by Acid Deposition in Guangdong Province
and Guangxi Autonomous Region, China, p. 110±114.
21
Cao, H., Gao, J., Shu, J., 1992. Study on the response of Pinus massoniana seedling to aluminium. Acta Ecol. Sin. 12, 239±246 (In
Chinese with English abstract).
Cao, H., Gao, X., Shu, J., 1990. Response of 105 species of plants to
simulated sulfur acid rain. China Environ. Sci. 1, 26±32.
Cao, H., Gao, Y., Shu, J., Liu, Y., Chen, Y., Wang, W., Sun, W., 1988.
Preliminary study on the relationship between acid precipitation and
®r decline of high elevation in the Emei Mountain. Res. Environ.
Sci. 1, 10±11 (In Chinese with English abstract).
Chameides, W.L., Kasibhatla, P.S., Yienger, J., Levy, H., II, 1994.
Growth of continental-scale metro-agro-plexes, regional ozone pollution and World food production. Science 264, 74±77.
Chang, Y., Hu, T., 1996. The economic cost of damage from atmospheric pollution in Chongqing. Manuscript, Chongqing
Environmental Prorection Bureau.
Chang, Y.-S., Arndt, R., Calori, G., Carmichael, G.R., Streets, D.G.,
Su, H., 1998. Air quality impacts as a result of changes in energy use
in China's Jiangsu province. Atmos. Environ. 32, 1383±1395.
Chang, Y.-S., Arndt, R.L., Carmichael, G.R., 1996. Mineral base cation deposition in Asia. Atmos. Environ. 30, 2417±2427.
Cosby, B.J., Hornberger, G.M., Galloway, J.N., Wright, R.F., 1985.
Modeling the e€ects of acid deposition assessment of a lumped parameter model of soil water and stream water chemistry. Water
Resour. Res. 21, 51±63.
Cronan, C.S., Grigal, D.F., 1995. Use of calcium/aluminum ratios as
indicators of stress in forest ecosystems. J. Environ. Qual. 24, 209±
226.
Dai, Z., Liu, Y., Wang, X., Zhao, D., 1997. Decrease in soil pH in
southern China within about 30 years. Water Air Soil Pollut., submitted for publication.
Downing, R.J., Ramankutty, R., Shah, J.J., 1997. RAINS-Asia: an
Assessment Model for Acid Deposition in Asia. The World Bank,
Washington, DC, ISBN 0-8213-3919-2.
EMAD (Expert Meeting on Acid Deposition), 1997. Final Report
from the Fourth Expert Meeting on Acid Deposition and
Monitoring Network in East Asia, 4±6 February, 1997. Environ.
Agency of Japan, Hiroshima.
Foell, W., Green, C., Amann, M., Bhattacharya, S., Carmichael, G.,
Chadwick, M., Cinderby, S., Haugland, T., Hettelingh, J.-P.,
Hordijk, L., Kuylenstierna, J., Shah, J., Shrestha, R., Streets, D.,
Zhao, D., 1995. Energy use, emissions and air pollution reduction
strategies in Asia. Water Air Soil Pollut. 85, 2277±2282.
Galloway, J.N., Zhao, D., Thomson, V.E., Chang, L., 1996. Nitrogen
mobilization in the USA and the People's Republic of China.
Atmos. Environ. 30, 1551±1561.
Gao, J., Cao, H., 1989. E€ects of ionic strength, pH and Ca/Al ratio
on aluminum toxicity of Masson pine seedlings. Acta Sci.
Circumstantiae 11, 194±198 (In Chinese with English abstract).
Hashimoto, Y., Sekine, Y., Kim, H.K., Chen, Z.L., Yang, Z.M., 1994.
Atmospheric ®ngerprints of East Asia, 1986±1991: an urgent record
of aerosol analysis by the JACK network. Environ. 28, 1437±1445.
Hettelingh, J.-P., Sverdrup, H., Zhao, D., 1995. Deriving critical loads
for Asia. Water, Air Soil Pollut. 85, 2565±2570.
Kucera, V., Fitz, S., 1995. Direct and indirect air pollution e€ects on
materials incuding cultural monuments. Water Air Soil Pollut. 85,
153±165.
Kucera, V., Henriksen, J., Knotkova, D., SjoÈstroÈm, C., 1993. Model
for calculation of corrosion cost caused by air pollution and its application in three cities. In: Costa, J.M., Mercer, A.D. (Eds.),
Progress in the Understanding and Prevention of Corrosion., vol.
I. Institute of Materials, London, pp. 24.
Larssen, T., Vogt, R.D., Seip, H.M., 1996. A comparison of soil and
water chemistry in a catchment in China with sites in Poland and
Norway. In: Pawlowski, L. (Ed.), Chemistry for the Protection of
the Environment II. Plenum press, pp. 421±434.
22
T. Larssen et al. / Environmental Science & Policy 2 (1999) 9±24
Larssen, T., Xiong, J., Vogt, R.D., Seip, H.M., Liao, B., Zhao, D.,
1998. Studies of soils, soil water and stream water at a small catchment near Guiyang, China. Water Air Soil Pollut. 101, 137±162.
Lei, H.-C., Tanner, P.A., Huang, M.-Y., Shen, Z.-L., Wu, Y.X., 1997.
The acidi®cation process under the cloud in southwest China observation results and simulation. Atmos. Environ. 32, 851±861.
Liao, B., Larssen, T., Seip, H.M., Vogt, R.D., 1994. Anion adsorption
and aluminum release from Chinese soils treated with di€erent concentrations of (NH4)2SO4 and NH4NO3. J. Ecol. Chem. 3, 281±301.
Liao, B., Seip, H.M., Larssen, T., 1997. Response of two Chinese forest soils to acidic inputs: leaching experiment. Geoderma 75, 53±73.
Liao, B., Larssen, T., Seip, H.M., 1998. Response of ®ve Chinese forest
soils to acidic inputs: batch experiment. Geoderma, 86: 295±316.
Lin, G., 1998. Energy development and environmental constraints in
China. Energ. Policy 26, 119±128.
Lin, G., Liao, B., Ding, R., 1992. A study on the bu€ering capacity of
the forest soil against acidic precipitation in several areas of China.
Chin. Geogr. Sci. 2, 126±132.
Liu, H., Du, X., 1991. A preliminary study on the characteristics of
fogwater in the Masson pine forest in Chongqing, China. J.
Environ. Sci. (China) 3, 11±16.
Liu, S., Huang, M., 1993. The e€ects of below-cloud aerosol on the
acidi®cation process of rain. J. Atmos. Chem. 17, 157±178.
Lydersen, E., Angell, V., Eilertsen, O., Larssen, T., Mulder, J., Muniz,
I.P., Seip, H.M., Semb, A., Vogt, R.D., Aagaard, P., 1997. Planning
of an Integrated Acidi®cation Study and Survey on Acid Rain
Impacts in China. Final Report to the World Bank. NIVA Report
SNO 3719-97, ISBN 82-577-3287-7.
Lùkke, H., Bak, J., Falkengren-Grerup, U., Finlay, R.D., Ilvesniemi,
H., Nygaard, P.H., Starr, M., 1996. Critical loads of acidic deposition for forest soils: is the current approach adequate?. Ambio 25,
510±516.
Ma, L.-Q., 1990 Absorption capacity of forest to SO2 as well as injury
of acid rain and atmospheric pollution to it in Chongqing. Report.
Meng, F., Wang, Z., Ge, M., 1996. Study on simulation of SOx transport-deposition in southeastern China. Res. Environ. Sci. 9 (5), 20±
25 (In Chinese with English abstract).
Meng, F., Xu, J., Zhang, J., Wang, Z., 1997. Sulfur Transport/deposition Modeling in Southeastern China. Manuscript. Chinese
Research Academy of Sciences, Beijing, China.
Mo, J., Brown, S., Lenart, M., Kong, G., 1995. Nutrient dynamics of a
human-impacted pine forest in a MAB reserve of subtropical China.
Biotropica 27, 290±304.
NEPA, 1997. The National Ninth Five-year Plan for Environmental
Protection and the Long-term Targets for the Year 2010. The
National Environmental Protection Agency, Beijing, China.
Nilsson, J., Grennfelt, P. (Eds.), 1988. Critical Loads for S and N.
Nordic Council of Ministers, Copenhagen.
Ning, D.-T., Zhong, L.-X., Chung, Y.-S., 1996. Aerosol size distribution and elemental composition in urban areas of northern
China. Atmos. Environ. 30, 2355±2362.
Ou, S., Pan, L., Zhuang, M., 1996. Estimation of the e€ects and economic loss caused by acid deposition in Xiamen area. Res. Environ.
Sci. 9 (5), 57±59 (In Chinese with English abstract).
Pan, G.X., 1992. Acidi®cation of soils in Mount Lushan over the last
35 years. Pedosphere 2, 179±182.
Pope, C.A., III, Xu, X., 1993. Passive cigarette smoke, coal heating
and respiratory symptoms of nonsmoking women in China.
Environm. Health Perspect. 101, 314±316.
Qi, L., Wang, W., 1990. The Character of Precipitation at Guangdong
and Guangxi Provinces in China. Report/Manuscript. Chinese
Research Academy of Environmental Sciences, Beijing, China.
Reichhardt, T., 1996. New US air pollution regulations are set for a
bumpy ride. Nature 384, 392.
Rodhe, H., Galloway, J., Zhao, D., 1992. Acidi®cation in South±East
Asia: prospects for the coming decades. Ambio 21, 148±150.
Seip, H.M., Zhao, D., Xiong, J., Zhao, D., Larssen, T., Liao, B., Vogt,
R.D., 1995. Acidic deposition and its e€ects in southwestern China.
Water Air Soil Pollut. 85, 2301±2306.
Shao, M., Tang, X., Li, J., Li, K., Yuan, S., 1995. The application of
accelerator mass spectrometry (AMS) in the study of source identi®cation of aerosols in China. Pure Appl. Chem. 67, 1457±1459.
Shu, J., Cao, H., Gao, Y., Liu, L., Gao, J., Yong, Y., 1993. Ecological
criteria for Masson pine e€ected by acidic precipitation and evaluation of economic loss. China Environ. Sci. 13 (4), 279±283.
Statistics China, 1983±1996. China Environmental Statistics Annual
Report. Beijing, China.
Suzuki, K., Maeda, K., Sasa, Y., Okada, A., Sakamoto, O., 1993.
Application of PIXE to source identi®cation of Kosa aerosol: analysis of desert soils in China. Nucl. Instr. Meth. B 75, 317±320.
Totsuka, T., Liang, Y., Fuzhu, Z., Zhongwei, F., 1994. E€ects of acid
precipitation on growth of Masson pine trees in Chongqing area,
China. In: Proceedings of China±Japan Joint Symposium: Impacts
of Salination and Acidi®cation on Terrestrial Ecosystems and their
Rehabilitation in East Asia, pp. 142±145.
Tsujino, Y., Satoh, Y., Matsumoto, M., Komeiji, T., Tanio, K.,
Kitamura, M., Zhen Hao, Zhang Danian, Chen Silong, Maeda,
Y., Bandow, H., 1995. Acid deposition and material damage in
China. Pure Appl. Chem. 67, 1407±1486.
UNDP, 1991. Control of Atmospheric Pollution from Coal
Combustion. United Nations Development Programme. Project
document CPR/91/213/B/01/99.
Wang, R., Yang, J., Tang, H., 1996. Impacts of Acid Deposition on
Ecosystems in China. Research report, Research Center for EcoEnvironmental Sciences, Academia Sinica, P.O. Box 934, Beijing
100083, China.
Wang, W., Wang, T., 1996. On acid rain formation in China. Atmos.
Environ. 30, 4091±4093.
Wang, W., Fu, C., Yutian, Z., Shaoxian, H., Dagang, T., Wanhua, Z.,
1997a. The Current State of Acid Rain in China. Report. Chinese
Research Academy of Sciences, Beijing, China.
Wang, W., Guoan, D., Tao, W., 1997b. Geographical distribution of
rain acidity over China. Water Air Soil Pollut., submitted for publication.
Wang, W., Hong, S., Zhang, W., 1995. Development of material
damage function for acid deposition. Acta Sci. Circumstantiae 15
(1), 30±31 (In Chinese with English abstract).
Wang, W., Wang, W., Chen, Y., Qi, L., Cai, Y., Ye, Q., Huang, X.,
1991. Chemical properties of cloud water in Jinding, Ermei mountain. China Environ. Sci. 11 (4), 245±246 (In Chinese with English
abstract).
Wang, W., Cao, H., Ning, J., Chen, Y., Ye, Q., Sun, W., 1988.
Interaction of acidic cloud droplet with and it's e€ects on forest
canopy in the Lingding zone of the Mount Emei. Res. Environ.
Sci. 1 (6), 29±30 (In Chinese with English abstract).
Wang, A., Huang, Y., Ma, C., Wang, Q., Yang, S., Liu, H., Li, M.,
Liu, J., 1981. Chemical characteristics of airborne particles in the
Beijing area. Acta Sci. Circumstantiae 1, 220±232 (In Chinese).
Wells, G.J., Xiping, X., Johnson, T.M., 1994. Valuing the Health
E€ects of Air Pollution: Application to Industrial Energy
Eciency Projects in China. Report No. 8 of China: Issues and
Options in Greenhouse Gas Emission Control. The World Bank.
WHO (World Health Organization), 1995. Update and revision of the
Air Quality Guidelines for Europe. Meeting of the Working Group
`Classical' Air Pollutants, Bilthoven, The Netherlands, 11±14
October 1994.
Williams, M.W., Yang, D., Liu, F., Turk, J., Melack, J.M., 1995.
Controls on the major ion chemistry of the UÈruÈmqi river, Tian
Shan, People's Republic of China. J. Hydrol. 172, 209±229.
Working Group on Public Health and Fossil Fuel Combustion, 1997.
Short-term improvements in public health from global-climate policies on fossil-fuel combustion: an interim report. Lancet 350,
1341±1349.
T. Larssen et al. / Environmental Science & Policy 2 (1999) 9±24
World Bank, 1997. Clear Water, Blue Skies: China's Environment in a
New Century. The World Bank, Washington DC, ISBN 0-82134044-1.
Xia, Y., Sakamoto, M., Qijun, K., Dehui, Z., Baoyuan, L., Zhihong,
L., Xiamin, L., Xiaoqing, X., 1994. E€ects of acidi®cation on freshwater ecosystem in southwest China. In: Proceedings of Cina±Japan
Joint Symposium: Impacts of Salination and Acidi®cation on
Terrestrial Ecosystems and Their Rehabilitation in East Asia, pp.
152±158.
Xie, Z., Kuby, M., 1997. Supply-side: demand-side optimalization and
cost±environment tradeo€s for China's coal and electricity system.
Energ. Policy 25, 313±326.
Xu, G., Zhouping, S., Okazaki, M., 1994a. E€ects of acid precipitation
on some soils under di€erent vegetation in Chongqing, China. In:
Proceedings of China±Japan Joint Symposium: Impacts of
Salination and Acidi®cation on Terrestrial Ecosystems and Their
Rehabilitation in East Asia, pp. 173±178.
Xu, X., 1996. Air pollution and its health e€ects in Chongqing, China.
Presentation at World Bank.
Xu, X., Dockery, D., Chen, Y., 1994b. Air pollution and daily mortality in residential areas of Beijing, China. Arch. Environm.
Health 49, 216±222.
Xu, Z.-Y., Blot, W.J., Xiao, H.-P., Yi-Ping Feng, A.W., Stone, B.J.,
Sun, J., Ershow, A.G., Henderson, B.E., Fraumeni, J.F., 1989.
Smoking, air pollution, and high rates of lung cancer in Shenyang,
China. J. Nat. Cancer Inst. 81, 1800±1806.
Xue, H.B., Schnoor, J.L., 1994. Acid deposition and lake chemistry in
southwest China. Water Air Soil Pollut. 75, 61±78.
Yin, S., Wang, A., Yang, S., Liu, P., 1996. Correlation of acid rain
with the distributions of acid and alkaline elements in aerosols.
Nucl. Instr. Methods B109/110, 551±554.
Zhang, F., Zhang, J., Zhang, H., Ogura, N., Ushikubo, A., 1996.
Chemical composition of precipitation in a forest area of
Chongqing, southwest China. Water Air Soil Pollut. 90, 407±415.
Zhao, D., Seip, H.M., Zhao, D., Zhang, D., 1994. Pattern and cause of
acidic deposition in the Chongqing region, Sichuan Province, China.
Water Air Soil Pollut. 77, 27±48.
Zhao, D., Seip, H.M., 1991. Assessing e€ects of acid deposition in
southwestern China using the MAGIC model. Water Air Soil
Pollut. 60, 83±97.
Zhao, D., Sun, B., 1986. Air pollution and acid rain in China. Ambio
15, 2±5.
Zhao, D., Wang, A., 1994. Estimation of anthropogenic ammonia
emissions in Asia. Atmos. Environ. 28, 689±694.
Zhao, D., Xiong, J., 1988. Acidi®cation in Southwestern China. In:
Rodhe, H., Herrera, R. (Eds.), Acidi®cation in Tropical Countries.
SCOPE, John Wiley & Sons, pp. 317±346.
Zhao, D., Zhang, X., 1990. Energy related environmental issues in
China: air pollution and acid rain. Report, Res. Center for EcoEnviron. Sci., Beijing. Presented at Fukuoka Int. Symp. 1990:
Global environ and Energy issues, 1990, Japan.
Zhao, D., Mao, J., Xiong, J., Zhuang, X., Yang, J., 1995a. Critical
load of sulfur deposition for ecosystem and its application in
China. J. Environ. Sci. 7, 325±337.
Zhao, D., Chen, C., Xiong, J., Zhang, X., Dai, Z., Mao, J., Seip, H.M.,
Vogt, R., 1995b. Acid reign 2010 in China? Report, Res. Center for
Eco-Environ. Sci., Beijing.
Zhao, D., Xiong, J., Xu, Y., Chan, W.H., 1988. Acid rain in southwestern China. Atmos. Environ. 22, 349±358.
Thorjùrn Larssen is Research Fellow in Environmental Chemistry
at the University of Oslo, Norway. His ®elds of interest include
biogeochemistry and metals mobilization in soils e€ects on vegetation from air pollutants as acid rain and photochemical oxidants and environmental problems in fast developing countries.
He earned an M.Sc. degree in environmental chemistry from the
University of Oslo in 1994 and is currently working on a Ph.D.
23
at the same university focusing on acid deposition and acidi®cation in China.
Hans Martin Seip is Professor at the Department of Chemistry,
University of Oslo; he also has a part-time position at Center for
Climate and Environmental Research Ð Oslo (CICERO). Fields
of interest include modeling of acidi®cation, e€ects of air pollutants on local, regional and global scales, and cost±bene®t analyses. He has cooperated with Chinese scientists for about 10
years. He earned a degree as graduate chemical engineer at the
Technical University of Norway in 1961 and a Ph.D. at
University of Oslo in 1967.
Arne Semb is a Senior Research Scientist at the Norwegian Institute
of Air Research.
Jan Mulder is Professor in Soil and Water Sciences at the
Agricultural University of Norway. His ®elds of interest include
hydrochemistry in catchments, interactions between metals and
humic substances in soils and soil plant relationships. He earned an
M.Sc. degree in soil science from the Wageningen Agricultural
University, The Netherlands in 1982 and a Ph.D. in Agricultural and
Environmental Sciences from the same University in 1988. Professor
Mulder is Associate Editor of the European Journal of Soil Science.
Ivar Pors Muniz holds a Ph.D. in biology and is working in the ®eld
of applied ecology and chemistry at NINA Ð Norwegian Institute
for Nature Research, Department of Landscape Ecology in Oslo,
Norway. His ®elds of interest are in environmental physiology/toxicology and chemistry, aquatic and terrestrial ecology, particularly
ecosystem interactions. He received his B.Sc. in zoology from the
University of Bergen, in 1974 and his Ph.D. in zoophysiology from
the University of Oslo in 1986.
Rolf D. Vogt is an Assistant Professor at the Environmental
Chemistry group at the University of Oslo, Norway. His ®elds of
interest include biogeochemistry and metals mobilization in soil by
long range transported air pollutants and environmental problems in
fast developing countries. He earned an M.Sc. degree in environmental chemistry from the University of Oslo in 1989 and a Ph.D. at the
same university in 1996.
Espen Lydersen is Research Leader at the Norwegian Institute for
Water Research. His ®elds of interest are water acidi®cation, aquatic
chemistry and toxicity. He earned a M.Sc. degree in limnology at the
University of Oslo in 1985 and a Ph.D. in limnology at the same university in 1992.
Valter Angell is director of the Information Department at the
Norwegian Institute of International A€airs (NIIA). His ®elds of
interest include international trade, development issues and environmental problems. He received the Cand. Oecon. degree from the
University of Oslo in 1969. He has been a Research Fellow at the
NIIA and Senior Economist in the World Bank.
Tang Dagang is Director and Associate Researcher at the
Atmospheric Environment Institute at the Chinese Research
Academy of Environmental Sciences, Beijing. He graduated from
Department of Technical Physics, Peking University and has been
working at the Particle Technology Laboratory at, University of
Minnesota, USA. His research interests includes aerosols and emission control of coal vehicles and coal combustion sources. He is a
committee member of the Aerosol Committee, the Chinese Society
of Particles and the Chinese Society of Chemical Engineering.
24
T. Larssen et al. / Environmental Science & Policy 2 (1999) 9±24
Odd Eilertsen is Assistant Research Director and scienti®c researcher
in vegetation ecology at NINA, Norwegian Institute for Nature
Research. His ®elds of interest and expertise are in biodiversity and
spatio-temporal dynamics on ground vegetation and e€ects and
counteractions of acidi®cation. He received a M.Sc. degree at the
Faculty of Mathematics and Natural Science, University of Oslo.