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Effects of affluence and population density on waste generation
and disposal of municipal solid wastes
Ko Matsunaga and Nickolas J. Themelis
Earth Engineering Center, Columbia University, New York
ABSTRACT
This paper compares the rate of generation and means for managing municipal solid wastes
(MSW) in Japan and the U.S. A top priority of federal and local government in Japan has been to
minimize the generation of wastes and reduce landfilling, by means of recycling and combustion
to generate electricity. As a result, the per capita generation of MSW in Japan is 56.1% of that in
the U.S.1-4 and only 20.3% of Japan’s MSW, including ash from incineration, is landfilled.1 In
contrast, about 14.8% of the U.S. MSW is combusted and 57.4% is landfilled, excluding ash from
incineration.3 This study also examined the management of MSW in several other countries and
attributes the pressure or impetus on governments to manage the generation and disposal of
wastes (called here the “MSW Index”) to the product of two measurable factors: Affluence (as
measured by the GNP per capita) and population density. A higher standard of living results in
more wastes and also greater ability to invest in waste management systems; high population
densities imply scarce land resources and thus more pressure to preserve land and environmental
quality. According to the MSW index, the pressure on high population density affluent nations,
such as Denmark, Luxembourg, the Netherlands, and Japan, is twice as high as that on U.S. and
Australia.
INTRODUCTION
Next to the production of cement, municipal solid wastes (MSW) represent the largest mass of
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solid materials generated by humanity. In the U.S., nearly 210 million tons of MSW are generated
annually. The reported MSW generation in OECD countries exceeds 600 million tons.5 The
principal means for managing the various materials contained in MSW are by recycling, recovery
of energy in Waste-to-Energy plants, anaerobic or aerobic bioconversion to a compost material,
and landfilling. The composition of the collected MSW depends principally on the economic
standard of living of a community. Within the developed nations of the world, the MSW
composition does not vary by much and is exemplified by the typical U.S. composition shown in
Table 1.3,5 However, there are substantial differences between Japan and the U.S. in a) the
amounts of MSW generated per capita, and b) the methods used for disposing wastes. For
example, an estimated 57.4% of the U.S. MSW is landfilled while in Japan, and more recently in
France and Germany, landfilling is considered to be environmentally undesirable and is allowed
only for the non-recyclable, non-combustible residues of MSW. The European Union (EU), in
consideration of the high global warming potential of methane emissions from landfills, has
established the EU Landfill Directive which is forcing cutbacks in the landfilling of wastes by
requiring the member states to reduce by 2016 the quantity of biodegradable material landfilled
to 35% of 1995 levels by 2016.6
Table 1. Principal Constituents of MSW in U.S., and Japan in 1990 (as % weight)3,5
The objectives of this industrial ecology study were to establish the rates of generation of MSW
in Japan and the U.S. and determine the underlying reasons for the differences in waste
management among these and other developed nations.
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MANAGEMENT OF MUNICIPAL SOLID WASTES IN JAPAN
Due to the scarcity of landfill spaces and attention to the environmental problems associated with
MSW disposal, there has been strong support for MSW management by citizens and government
at all levels. As a result, Japan is now one of the leading countries in managing waste generation.
The rate of MSW generation in Japan (principally residential and commercial wastes) in fiscal
1999 totaled 53.7 million tons1 (Figure 1). This corresponded to a per capita generation of 0.42
metric tons per year. The present means of MSW management in Japan are shown in Figure 2.1 It
can be seen that 74.5% of the total MSW was combusted and only 20.3% was landfilled,
including ash from incineration.
Figure 1. Total and per capita solid waste generation in Japan13
Figure 2. Flow and means of disposal of MSW in Japan in 1999, in million metric tons (% of
total MSW is shown `in parentheses)1
Waste reduction efforts in Japan
Waste management in Japan is mainly the responsibility of local government. There are several
waste-reduction methods such as reusing shopping bags or requesting people to bring their carryon bags while shopping; minimization of packaging materials; extending the life of products; and
design of products so as to reduce the use of materials (de-materialization).
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Re-use and recycling
Recycling is very successful in Japan with regard to some materials: In 1999, an estimated 55%
of the paper, 78-83% of metal cans, and 22.8% of PET bottles were recycled.7-10 As of April 2001,
air-conditioners, television sets, washing machines and refrigerators are required to be recycled
by the user, at a certain fee. The target is to close the material loop. The local government (e.g.,
at Nagoya, population 2.18 million) has organized recycling “flea” markets where people can buy
used products and materials. It is difficult to determine the volume of such re-use activities. On
the other hand, the volumes of recycled materials are recorded by each company and industry.
The following sections discuss the recycling of metals, plastics, paper, glass, steel can, aluminum
can, paper, and polyethylene terephthalate (PET) plastic containers.
The overall reported
recycling rate in Japan is reported to be 13% of the MSW collected.1
Metal recycling
There are two types of metal can, steel (54% of total) and aluminum (46%). The recycling rate of
steel cans has been estimated at 82.9% and of aluminum at 78.5%.7,8 Steel cans are used as drink
containers in E.U., Japan, and South Korea but not in the U.S.
Figure 3. Production and recycling of steel cans in Japan7
At this time, aluminum cans are the most popular containers for drinks all over the world. It is
interesting to note that although there is no deposit system for aluminum cans in Japan, the
recycling rate (78.5%)8 is higher than in the U.S. (62.5%)8. However, the total demand is much
higher in the U.S. (1.4 million tons per year vs. 0.28 million in Japan8 (Figure 4).
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Figure 4. Production and recycling of aluminum cans in Japan8
Paper recycling
Figure 5 shows that although the consumption of paper in Japan increased in the last decade of
the 20th century, some of the use of virgin paper has been replaced by recycled stock. Table 2
compares the per capita consumption of paper in Japan (249.9 kg) with several other countries.9
Figure 5. Production and recycling rate of Paper in Japan9
Table 2. Annual Paper Consumption in some countries (kg per capita) 9
Plastics recycling
The global use of polyethylene terephthalate (PET) containers has been growing steadily, due to
their lightness, convenience of use, and recyclability. PET usage is expected to grow at 10% per
year and some countries have started to use PET containers for beer.10 The per capita annual
consumption of PET containers in Japan is 2.9 kg and in the U.S. 5.6 kg10. PET demand in Japan
is increasing as people move away from tap water, for fear of contamination, to bottled water.
Figure 6 reflects this trend.
Recycling of PET is not popular as yet in Japan and there is no deposit system. The first
recycling center for PET-bottles was established in 1993 but there was not enough recycled
material to supply the PET plants. In contrast, the first recycling factory in the U.S. was built in
1977 and in EU in 1980. In the recycling of PET bottle, some material is converted to plastic
fibers.
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Figure 6. Production and recycling of PET containers in U.S., Japan, and E.U.10
Glass recycling
Glass is used extensively in Japan in beer, milk and sake bottles. However, PET containers are
making inroads in these markets. The recycling rate of glass bottles is very high, 77.8% in 2000.11
Figure 7 shows the global production and recycling rates of glass bottles in the period 1991-1999.
Figure 7. Glass bottle production and recycle in the world11
Waste-to-Energy in Japan
As noted earlier, Japan has tried to reduce waste generation and re-use or recycle as much as
possible of the MSW generated. Due to land limitation, the first priority in Japan has been to
reduce the amount of landfilled waste. As a result of this long-standing policy, presently 74.5% of
waste goes to combustion plants, in contrast to only 14.8% in the U.S. Thus, only 6.3% of the
MSW is directly landfilled in comparison to about 57.4% in the U.S.1,3
There are 1717 combustion plants in Japan of total capacity of 193,00 tons per day; of
these, 1103 (64.2%) are Waste-To-Energy (WTE) plants and 215 plants (12.5%) generate a total
of 1060 MW1. In comparison, there are 102 WTE facilities in the U.S. and generate 2,800 MW.
Waste management regulation in Japan
At the beginning of 2001, concern for the environment led to elevating the Agency of the
Environment to a Ministry by the government of Japan. There are several regulations concerning
waste management including:
The Basic Environment Law: This law became effective in 1993 to address new major problems
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such as global warming. The law declares the basic principles of environmental policy, defines
the responsibilities of each actor in the society, prescribes the policy instruments to protect the
domestic and global environment, and establishes three basic principles of environmental policy:
•
The blessings of the environment should be enjoyed by the present generation and by
successive generations (the UN concept of sustainable development).
•
A sustainable society should be created where environmental loads by human activities are
minimized.
•
Japan should contribute actively to global environmental conservation through international
cooperation.
Other environmental laws relating to MSW management are: Air Pollution Control Law; Water
Pollution Control Law; Environmental Impact Assessment Law; Recycling law of specific home
electrical products; Law in support of the use of recycled resources.
MANAGEMENT OF MUNICIPAL SOLID WASTES IN THE U.S.
Generally speaking, waste reduction is not a prominent issue in the U.S., although cities like
Chicago, Loa Angeles and New York have mounted public information programs aimed at waste
minimization. The per capita generation of MSW is about 720 kg per year 12. This is 80% higher
than that in Japan and the highest per capita waste generation in the world. Some of the reasons
are a lifestyle where “easier” and “larger” are preferred and most people can afford them; usually,
there is no direct charge for MSW and thus no incentive to reduce; also, there is no concerted
effort by the federal government in the direction of waste minimization. For example, the postage
rates for “junk” mail are very low. There is little re-use of products in the U.S., apart from
automobiles, although the web has encouraged the development of “waste exchanges” where
people trade used objects. With regard to recycling, the reported overall rate in the U.S. is 22.1%3,
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in comparison to the 13.0% rate of recycling in Japan. However it should be noted that the rate of
waste generation in the U.S., and thus the opportunity for recycling, is greater than in Japan.
Unlike Japan and some European nations, the U.S. federal and state governments do not
restrict the use of land for landfilling. Of course, there are special circumstances, such as the
closing of the giant Fresh Kills landfill by New York City and State. However, these are dictated
by political pressures rather than by environmental concerns; for example, in the case of Fresh
Kills, most of the MSW is now exported to other states for landfilling, at the additional
environmental cost of ten million gallons of trucking fuel12.
Waste management regulations in the U.S
As in the case of Japan and other developed nations, the federal government in the U.S. has set as
its main policy “reducing, reusing, and recycling”.3,13 However, the fourth, and major, tool of
waste management in Japan, for example, the recovery of energy and materials by means of
Waste-to-Energy facilities, is not promoted by U.S. federal policy.
Some of the U.S. laws that relate to waste management are: The Resource Conservation
and Recovery Act (RCRA); RCRA Regulations (40 CFR Parts 240-299); Mercury-Containing and
Rechargeable Battery Management Act; RCRA Hotline Training Modules - "Introduction to
Other Laws that Interface with RCRA"; RCRA Hotline Training Modules - "Introduction to RCRA
Statutory Overview".
COMPARISON OF MSW MANAGEMENT IN JAPAN AND THE U.S.
As discussed earlier, both governments espouse the three basic steps of reducing the amount of
MSW to landfills: Reduce, reuse and recycle.3,13 The fourth basic step, used principally in Japan
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and to a certain extent in the U.S., is the recovery of energy from wastes. In Japan, the
government has made waste reduction an integral part of the national policy for waste
management and succeeded in reducing the total amount of waste. In the U.S., there is little
movement in this area. This is apparent from Table 3 that compares the per capita generation of
various components of the MSW stream, in Japan and the U.S.1,3,5
Table 3. Waste Composition in Japan and U.S. (in million tons)1-5
“Re-use” of products sounds like a reasonable way to go but, with the exception of
automobiles, very few products are actually re-used in affluent nations like Japan and the U.S.
The amount of re-use would increase if there were re-manufacturing processes that guarantee
product reliability.
Table 4 summarizes the findings of this study with regard to waste generation and
management in Japan and the U.S.1-4 Figure 8 summarize the means used for managing of the
generated MSW in Japan and the U.S.1-4
Table 4. Waste management and composition in Japan and U.S. (in million tons and as % by
weight)1-4
Figure 8. MSW management in Japan and the U.S.1-4
FACTORS INFLUENCING MSW GENERATION AND MANAGEMENT
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Affluence
One of the objectives of this study was to determine whether there is a relationship between
affluence, as measured by the per capita GNP, and government and public attitudes towards
MSW reduction and management. Figure 9 shows the rate of MSW generation for several
nations as a function of GNP.5 Also, Figure 10 shows how the generation of MSW has changed
with time for several nations.5 A comparison of the Japan and U.S. plots in Figure 9 indicates that
some other factor, apart from culture or history, may play a role in shaping government and
public attitudes towards the MSW issue.
Figure 9. Relation between GNP and generated MSW in several countries5
Figure 10. Relation between MSW and year5
Population density
Historically, the disposal of MSW became an issue first in highly populated areas, such as New
York City. The issue of proper disposal came later as the standard of living in urban areas
improved. Affluence implies the abundance of goods. The use of goods results in the generation
of wastes. Also, an affluent society is bound to care more and spend more on the disposition of
wastes. Furthermore, between two affluent communities, the one that possesses less land per
person is bound to be more careful regarding the use of land for MSW disposal. This line of
reasoning led us to seek a correlation between the pressure or impetus on government and public
to manage properly the municipal solid wastes and two readily quantifiable factors: GNP per
capita, which represents affluence, and population density, which represents land scarcity.
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Impetus for better MSW management = MSW Index = f[(GNP per capita), (population density)]
(1)
The most likely function is the product of these two factors, since the effects are clearly additive.
The power exponent of each function will depend on its relative importance in increasing the
impetus for MSW management. The products of the available GNP and population density data
were computed in various combinations for a large number of nations and the results were
compared to the known data regarding waste generation and means of management. The most
promising combination at this time was as follows:
MSW Index for MSW management = (GNP/ population) (population/surface area)
= (GNP/surface area)
(2)
The higher the value of this function is for a particular geographic area, the greater will be the
pressure for establishing a good MSW management system. The rationale is simple enough. With
little money (low GNP per capita), people cannot buy products and also tend to hold on to
whatever they own or can find. Affluent people dispose much and also can afford better waste
management systems. Finally, the higher is the population density, the better MSW management
is required due to sanitation problems and the cost of land.
On the basis of equation 2, Luxembourg has the highest impetus index, followed by Japan, the
Netherlands, and Belgium (Figure 11). Figure 11 also shows that the MSW Index for the U.S. is
not very high and this may explain the relative lack of government and public interest in MSW
management. Nations at an Index number above 3, such as South Korea, are under extreme
pressure to control the MSW flow and already taking steps in that direction.
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Figure 11. Relation between Waste Index and year
A question arises with regard to two Scandinavian nations, Norway and Sweden, that are
known for sound MSW management and yet, according to the impetus index, they are not under
strong pressure. It is clear that some other factors, such as culture, may need to be included in the
correlation of Equation 2.
CONCLUSIONS
High GNP per capita reflects the ability of people to purchase goods. The use of goods eventually
leads to the generation of municipal solid wastes. Also, affluence affords the provision of better
systems for the management of wastes. However, this study made clear that some other factor
than GNP per capita influences policies and actions regarding the generation and management of
MSW. For example, Japanese citizens, although at nearly the same standard of living as in the
U.S. and U.K., generate only 56.1% of the U.S. per capita MSW. Also, Japan landfills only
20.3% of its MSW, including the WTE ash, plants, and combusts 74.5% of its MSW in costly
Waste-to-Energy facilities that convert solid wastes to electric energy and heat. In contrast, the
U.S. landfills 57.4% of its MSW and combusts only 14.8% of its MSW. Therefore in both
respects, control of generation of wastes and technologies used for managing wastes, Japan is
ahead of the U.S. This study showed that the second most important factor in influencing
government and public attitudes toward waste management, at the national level, is population
density. Higher densities demand better management of MSW because of sanitation problems and
the scarcity and cost of land.
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The impetus on governments and people for better management of MSW was expressed as the
ratio of GNP to land surface.
The higher is this index, the greater is the need for more advanced MSW management.
For example, the Netherlands regulated recycling of used electrical products since 1999. Japan
regulated the recycling of air-conditioners, washing machines, TVs and refrigerators, as of April
2001. Both countries have the highest indices, next to Luxembourg. Also, most of the EU
countries have a high index, which explains the high concern of EU for environmental issues.
South Korea's index of 2945 in 1997 is growing and already it exceeds that of the U.S.
(610 in 1997). In the last two years, South Korea has embarked on a MSW improvement
program that includes the construction of Waste-to-Energy pants. An inspection of the derived
MSW index shows that most nations fit in the expected pattern. There remain questions to be
answered by further analysis. For example, two Scandinavian nations, Norway and Sweden, are
known for advanced MSW management. Yet, according to their impetus index, they are not under
strong pressure. It is clear that some other factors, such as culture, can influence national attitude
towards waste management. Further work in this research center will attempt to improve on our
understanding of the influential factors and develop the preliminary MSW-Index that was
presented in this report.
REFERENCES
1. Generation and Management of MSW in 1999 in Japan. Minister of environment in Japan.
2002. In public.
2. Population data. Statistics Bureau & Statistics Center, Japan. 1999. In public.
3. U.S. Environmental Protection Agency. MUNICIPAL SOLID WASTE IN THE UNITED
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STATES: 1999 FACTS AND FIGURES. In public.
4. National Population Projections, I. Summary Files. U.S. Census Bureau, Population Division,
Population Projections Branch. 2000. In public.
5. OECD Enviromental Data (Donnees OCDE sur l’environnement), 1999.
6. European Environment Agency. Working Paper Update on the environmental dimension of
the EU Sustainable Development Strategy from Environmental signals 2002 (forthcoming)
Prepared for Environment Council, 4 March 2002. In public.
7. Japan
Steel
Can
Recycling
Association,
Japan.
Submitted
for
publication.
http://tomcat.rits.or.jp/steelcan/
8. Japan Aluminium Can Recycling Association, Japan. Submitted for publication.
http://www.alumi-can.or.jp/
9. Advertisement section; The Paper Recycling Promotion Center in Japan, In public.
(http://www.prpc.or.jp/)
10. PET bottle Recycling association, Japan. Submitted for publication.
http://www.petbottle-
rec.gr.jp/english/index.html
11. Glass Bottle Recycling Promoter Association, Japan. Submitted for publication.
http://www.glass-recycle-as.gr.jp/
12. Columbia University 2001 “Life After Fresh Kills”. (http://www.columbia.edu/cu/earth)
13. Yukio Shioda; Zyunichi Yamaguchi. Gomi no hanashi (Story of waste); Minister of
environment in Japan. 1996.
End
About the Authors
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Nickolas J. Themelis
Director, Earth Engineering Center,
Stanley-Thompson Professor, Earth and Environmental Engineering
(Henry Krumb School of Mines), Columbia University
500 West 120th St.#1047 Mudd , New York, NY 10027; e-mail: [email protected]
web page: www.columbia.edu/cu/earth
Ko Matsunaga
Junior Research Associate, Earth Engineering Center, Columbia University
E-mail: [email protected]
Mitsubishi Heavy Industries., Ltd.
E-mail: [email protected]
B.S. Keio University
M.S. IEOR, Earth Resources Engineering Columbia University
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LIST OF FIGURES
Figure 1. Total and per capita MSW generation in Japan13
Figure 2. Flow and means of disposal of MSW in Japan in 1999, in million metric tons (and as %
of total MSW in parentheses)1
Figure 3. Production and recycling of steel cans in Japan7
Figure 4. Production and recycling of aluminum cans in Japan and the U.S.8
Figure 5. Production and recycling rate of paper in Japan9
Figure 6. Production and recycling of PET containers in U.S., Japan, and E.U.10
Figure 7. Production and recycling of glass bottle in Japan11
Figure 8. MSW management in Japan and the U.S.1-4
Figure 9. Per capita generation of MSW vs. GNP in various nations5
Figure 10. National trends in MSW generation5
Figure 11. National MSW Indices vs. time
LIST OF TABLES
Table 1. Principal constituents of MSW in Japan and the U.S. (as % weight)3,5
Table 2. Per capita annual consumption of paper in different nations (kg)9
Table 3. Waste composition in Japan and the U.S. (in million tons)1,3,5
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Table 4. MSW generation and management in Japan and the U.S.
(in million tons and % by weight)1-4
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Figure 1. Total and per capita MSW generation in Japan 13
Collected
Landfill
53.7 (100%)
3 4 (6 3%)
Total
landfill
10.9 (20.3%)
To combustion
40 0 (74 5%)
To
disassemble
and separation
To recycling
4 4 (8 2%)
Collection
and
disposal by other
0.4
Total
recycled
7.0 (13.0%)
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Figure 2. Flow and means of disposal of MSW in Japan in 1999, in million metric tons (and as %
of total MSW in parentheses)1
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Figure 3. Production and recycling of steel cans in Japan7
Figure 4. Production and recycling of aluminum cans in Japan and the U.S.8
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Figure 5. Production and recycling rate of paper in Japan9
Figure 6. Production and recycling of PET containers in U.S., Japan, and E.U.10
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Figure 7. Production and recycling of glass bottle in Japan11
Figure 8. MSW management in Japan and the U.S.1-4
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Figure 9. Per capita generation of MSW vs. GNP in various nations5
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Figure 10. National trends in MSW generation5
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Figure 11. National MSW Indices vs. time
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Table 1. Principal constituents of MSW in Japan and the U.S. (as % weight)3,5
Paper and
Food and
carton
garden waste
Plastics
Glass
Metals
Country
Japan
38
32
11
7
6
U.S.
38.1
28.3
10.5
5.5
7.8
Textiles, etc
7
9.8
Table 2. Per capita annual consumption of paper in different nations (kg)9
Paper consumption(kg)
Country
Australia
242.2
Austria
193.3
Belgium
340.7
Canada
243.1
Denmark
269.4
Finland
351.7
France
192.8
Germany
232.5
Italy
189.6
Japan
249.9
Luxembourg
260.0
Netherlands
272.9
New Zealand
181.5
Norway
227.6
Spain
172.2
Sweden
277.1
Swiss
246.0
Taiwan
229.4
UK
215.8
US
331.7
Nation
Japan
U.S.
Table 3. Waste composition in Japan and the U.S. (in million tons)1,3,5
Paper and Food and plant
Plastics
Glass
Metals
carton
waste
20.2
17.0
5.8
3.7
3.2
78.8
58.6
21.7
11.4
16.1
Textiles, etc
3.7
20.3
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Table 4. MSW generation and management in Japan and the U.S.
(in million tons and % by weight)1-4
Recycling Compos- CombusLandNation Year Population,
Total
ting
tion
filling
millions
amount
of MSW
Japan 1999
126.7
53.7
4.4
Unknown
40.0
3.4
8.2%
N/A
74.5%
6.3%
U.S.
1999
273.6
206.9
45.7
11.8
30.6
118.7
22.1%
5.7%
14.8%
57.4%
Disassemble and
separation
5.9
11.0%
Unknown
N/A