Stage 2 Research Program 2003 - 2005
Technical Report No. 17
March 2006
The loads of particulate matter and atmospheric nitrogen deposited
from wet and dryfall to Adelaide metropolitan coastal waters.
The loads of particulate matter and atmospheric nitrogen deposited from wet
and dryfall to Adelaide metropolitan coastal waters
Author
Jeremy Wilkinson, Erick Bestland, Lynn Smythe, Nicholas White.
Department of Environmental Health
Flinders University of SA
GPO Box 2100
Adelaide SA 5001
Copyright
© 2005
South Australian Environment Protection Authority
This document may be reproduced in whole or in part for the purpose of study or training,
subject to the inclusion of an acknowledgement of the source and to its not being used for
commercial purposes or sale. Reproduction for purposes other than those given above requires
the prior written permission of the Environment Protection Authority.
Disclaimer
This report has been prepared by consultants for the Environment Protection Authority (EPA)
and the views expressed do not necessarily reflect those of the EPA. The EPA cannot
guarantee the accuracy of the report, and does not accept liability for any loss or damage
incurred as a result of relying on its accuracy.
ISBN 1 876562 98 6
March 2006
Reference
This report can be cited as:
Wilkinson, J., Bestland, E., Smyth, L., and White, N., (2006). “The loads of particulate matter
and atmospheric nitrogen deposited from wet and dryfall to Adelaide metropolitan coastal
waters.” ACWS Technical Report No. 17 prepared for the Adelaide Coastal Waters Study
Steering Committee, March 2006. Flinders University of South Australia
Acknowledgement
This report is a product of the Adelaide Coastal Waters Study. In preparing this report, the
authors acknowledge the financial and other support provided by the ACWS Steering
Committee including the South Australian Environment Protection Authority, SA Water
Corporation, the Torrens Patawalonga and Onkaparinga Catchment Water Management
Boards, Department for Transport Energy and Infrastructure, Mobil Refining Australia Pty Ltd,
TRUenergy, Coast Protection Board and PIRSA. Non-funding ACWS Steering Committee
members include the Conservation Council of SA, SA Fishing Industry Council Inc, Local
Government Association, Department of Water Land and Biodiversity Conservation and
Planning SA.
Acknowledgements
The authors would like to acknowledge the following individuals for their assistance
with data or other invaluable material or knowledge: Peter Christy of EPA and Peter
Clemmett of BOM.
Adelaide Coastal Waters Study Technical Report No. 17
iv
Contents
Executive Summary .................................................................................................... vi
1.
2.
3.
Introduction.......................................................................................................1
Background ......................................................................................................2
Methodology.....................................................................................................2
4.
4.1
Results .............................................................................................................4
Wetfall and Dryfall Nitrogen Load.............................................................4 4.2
Wetfall, Washout and Individual Rainfall Events ......................................5 4.3
Dryfall Particulate Matter ..........................................................................9
4.4
High-volume Sampler Particulate TKN...................................................11 4.5
High-volume Sampling Particulate Composition ....................................11
5.
Conclusions....................................................................................................23
6.
References .....................................................................................................24
Appendix I: The Wetfall Collector Located at BOM, Adelaide Airport ........................26 Appendix II: Analysis flow diagram for high volume air sample filter papers. ............27 Appendix III: Concentrations of TKN nitrogen collected on high volume air sampler filters per cubic metre of air sampled and per gram of particulate matter collected .
................................................................................................................28
Appendix IV: Comparison of mass of element in digest of blank and exposed filters....
................................................................................................................29
Appendix V: Mass of element in digest of exposed filters..........................................30 Appendix VI: Mean concentrations of elements analysed for in high volume air samples. ...............................................................................................................33 Appendix VII: Multiple scatter plots of minor and trace elements in Adelaide high volume air samples. .............................................................................................34 Appendix VIII: Dry deposition of nitrogen species to the central and northern Adelaide Metropolitan Area and 2km buffer strip for estimating N load (prepared by M. Hartley, South Australian EPA). ...........................................................................36 Adelaide Coastal Waters Study Technical Report No. 17
v
Executive Summary
The contribution of dryfall and wetfall to inputs of nitrogen into metropolitan Adelaide
Coastal Waters is a minor component of the overall load as is illustrated in Figure 1.
Rainfall contributes over 50 % of the water entering a 5 km wide near-shore strip
along the Adelaide Coast. Although significant in volume, the very low concentrations
of nitrogen and other pertinent constituents in rainwater when compared to the high
concentrations in waste water from treatment plants (WWTP) and storm flows,
makes the wetfall source relatively insignificant. This wetfall input deposits around 30
tonnes N per year of the total nitrogen load, or less than 1% of the annual load from
the combined WWTP, stormwater and groundwater sources. Similarly dryfall
contributes less than 1% of total nitrogen. Dryfall or dust deposition does contribute a
significant component of the solids input to the coastal strip with approximately 18%
of the annual load, approaching 2000 tonnes.
Flow
391 GL
2.0, 1%
62.0,
16%
114.2,
29%
213.0,
54%
WWTP
Wetfall
Stormwater
Penrice
Dry Fall
Groundwater
TN 2453 Tonnes
WWTP
Wetfall
1204.2,
49%
15.3, 1%
Stormwater
Penrice
NOxN 486 Tonnes
6849,
67%
Particulates 10337 Tonnes
WWTP
Stormwater
Dry Fall
Groundwater
766.8, 40%
1000.0,
52%
150.7, 6%
16.8, 1%
WWTP
Stormwater
20, 6%
1.9, 1%
Dry Fall
Wetfall
Cu 4.5 Tonnes
0.23, 5%
WWTP
WWTP
Stormwater
Dry Fall
Wetfall
Penrice
Pb 3.0 Tonnes
0.21, 7%
2.96,
66%
Stormwater
Penrice
335, 92%
1.34, 44%
1.31, 29%
Wetfall
4.9, 1%
437.5,
90%
Stormwater
114.2, 6%
15.3, 1%
Dry Fall
TP 361 Tonnes
12.7, 3%
36.0, 7%
WWTP
Dry Fall
TKN 1913 Tonnes
50.0, 2%
1000.0,
41%
32.8, 1%
1579, 15%
1852,
18%
Dry Fall
1.47,
49%
WWTP
Stormwater
Dry Fall
Figure 1. Summary diagram showing the contribution of wetfall and dryfall to ACWS
area loads.
Since particulates have elevated lead and copper, they have also contributed a
significant component of the total copper (5%) and lead (44%). With gradual
replacement of leaded petrol with unleaded petrol since the late 1980s, the
concentration of lead in air has declined dramatically. This has also reduced the
Adelaide Coastal Waters Study Technical Report No. 17
vi
indirect inputs of lead to the near-shore zone because stormwater now carries
significantly less lead (-65%). In the early 1990s the lead load to the immediate
coastal zone was around 2 tonne/y, and is now near 400 kg/y.
Adelaide Coastal Waters Study Technical Report No. 17
vii
1.
Introduction
The direct input to the Adelaide coastal water zone of dissolved and solid material from
atmospheric sources (wetfall and dryfall) has been a largely unknown quantity with the
exception of nitrogen and phosphorus deposition estimates from rainwater for the Adelaide
area (Clark, 1987). What has not been addressed is the dryfall load which could be
significant given the severity of wind and dust conditions in the Adelaide area. Specifically,
strong northerly winds with visible dust loads occur several times a year, especially during
late spring and early summer. These dust-laden winds are commonly followed directly by
cool fronts that can produce rainfall. One question addressed by this project is how
background rates of wetfall and dryfall compare to these large northerly dryfall events just
described, and, what component of the dissolved and solid input to the coastal zone is
contributed by atmospheric sources (Refer stakeholder issue # 3.2.1.2).
The significance of wind-blown dust in the marine realm has been noted for some time
(Darwin, 1846). However, both the quantification of its input and the realisation of its impact
have only recently been appreciated (Prospero, 1999; Shinn et al., 2000; Castro and
Driscoll, 2002). The data collected and analysed in Sub-program 4 provide a first
approximation of the quantities and composition of dryfall and wetfall input to the Adelaide
coastal zone. A quantitative assessment of pre-European and Pre-Indigenous dust
accession levels in the Adelaide area, as has been done elsewhere from sediment cores
(Pye, 1987; Busacca et al., 1998), is outside the scope of the Adelaide Coastal Waters
Study.
Previous workers (Pye, 1987; Shinn et al., 2000) have shown that in some semi-arid to
humid regions the wetfall and dryfall deposition of nutrients in particular nitrogen has been
shown to be significant compared to other sources. In fact, a previous study in the Adelaide
area (Clark, 1987), found significant nitrogen and phosphorus deposition from rainwater (2-6
kgTKN/Ha/yr, 1.2 kgNOx/Ha/yr in the late 1970s) as well as significant deposition of sea
salts (Kayaalp, 2001). The question addressed by Sub-program 4 is how do these inputs
from wetfall and dryfall total-up in the coastal zone and how do these totals compare to
waste water and stormwater inputs.
In some urbanised parts of the world, wet deposition to estuaries of oxidised nitrogen
species has been shown to be not only substantial, but a major component of the nitrogen
load. Wet deposition of NO3- at the rural sites of Chiang Mai and Nan (Bangkok Thailand)
ranged from 2.1 to 3.2 kg N/ha/y, while at the urban sites near estuaries this ranged from
about 6 kg N/ha/y, in Chiang Mai and Nan Cities to 8.6 kg N/ha/y, in Bangkok. Wet
deposition of NH4+ at the rural sites was about 2.4 to 3.6 kg N/ha/y, and at the urban sites of
Chiang Mai, Nan and Bangkok this was 7.7, 4.9 and 8.1 kg N/ha/y, respectively (Paramee et
al., 2005).
Nakamura et al. (2005) found that the atmospheric deposition of nitrogen to the South China
Sea was comparable to the riverine input of the Changjiang River. Nitrogen from
atmospheric inputs to the estuaries of the Mid-Atlantic Region of the United States of
America was an important component of the budget, with deposition rates varying between
2.7 and 10.8 kg N/ha/y (Castro and Driscoll, 2002).
In dryer areas it has been found that rates of atmospheric deposition can be very high; in the
order of 70 to 150 kg/ha/y (Singer et al., 2003), although nitrogen is a small component of
this as the particulates are largely mineral and not rich in organic matter. Singer et al. (2003)
found that average NCP (nitrogen, carbon and phosphorus) dry deposition fluxes were
equivalent to 12.3, 6.9 and 6.6 kg N/ha/y, and non-nitrate containing particulate dry
Adelaide Coastal Waters Study Technical Report No. 17
1
deposition fluxes were 17.0, 12.3 and 10.1 kg N/ha/y, at highway intersections, coastal and
suburban areas, respectively. NCPs < 10 µm in size contributed 3.4%, 9.6% and 6.4% by
weight to the total dry deposition at the highway intersection, coastal, and suburban areas,
respectively, showing that over 90% of dry deposition was particulates larger than 10 µm in
diameter (Yang et al., 2004). By comparison, the average total (wet plus dry) nitrogen
deposition to the Tampa Bay Estuary was 7.3 (+/- 13) kg N/ha/y, (Poor et al., 2001). For
Chicago, Lestari et al. (2003) measured dry deposition fluxes of sulfate and nitrate of
between 1.0–4.0 and 0.5–3.9 mg(m2/d), respectively (Lestari et al., 2003).
This investigation quantifies loads and estimates overall deposition to the ACWS study area.
Wetfall samples were collected and analysed for a variety of dissolved constituents and dry
samples derived from high volume air sampling filters were analysed for nitrogen, major,
minor, trace and rare earth elements. Point loads were extrapolated to provide estimates of
deposition across the ACWS study area using the north to south distribution of urbanized
area in the Adelaide airshed.
2.
Background
The Adelaide airshed and general climatic conditions of the Adelaide area are conducive for
significant loads of atmospheric origin to be delivered directly to the coastal zone. The
strong Mediterranean climate of the area with its long dry summer combined with strong
northerly winds that occur during high to low pressure changes produces significant dust
deposition. Several significant dust deposition events occur each year. Major dust sources
include organic and other detritus that collects on impervious urban surfaces (roads, parking
lots, and roofs), agricultural fields especially to the north of Adelaide in the North Adelaide
Plains, and tidal-estuary mudflats. Major gaseous sources of pollution relevant to the coastal
zone include motor vehicles, cement plants, and other industrial activity. It is generally
thought that burning of fossil fuels is the source of most NOx and SOx (NPI, 2000).
3.
Methodology
The selection of dust sampling sites was constrained by existing high-volume dust sampling
sites maintained by the EPA. The Osborne site was chosen because it is the most proximal
high-volume sampler to Gulf St Vincent and is approximately in the middle of the airshed.
Only one high-volume sampler was analysed due to time and budget constraints for this
sampling. The rainfall collector was deployed at the Adelaide Airport due to the airports
central and near coastal location (within 1.5 km of the coast) and adjacent to the Airport
Bureau of Meteorology weather monitoring station (photos: Appendix I).
In order to estimate urban pollution loads to the coastal strip, the Adelaide airshed was
segmented on a north to south axis according to the percentage urbanised land cover which
was used to proportion the atmospheric loads. In addition estimates of the dry deposition of
nitrogen were provided by the EPA air quality modelling group (Appendix VIII), these were
used to compliment the values estimated from the high-volume filter analyses and
calculations.
In the Adelaide area, the EPA has collected particulate matter from the air column for
approximately the past 20 years. Also included in the EPA dataset are particulate matter
samples from the Port Pirie area. The samples are from high volume dust samplers which
trap dust on glass fibre mats. These samplers record the volume of air that has passed
through the sampler so that mass of particulate matter per volume of air can be calculated.
Adelaide Coastal Waters Study Technical Report No. 17
2
Particulate matter samples have been continuously collected over this 20 year time frame
for various of the sites at a frequency of one day in every six. Each sampling period is for 24
hours. The samples are archived in Adelaide under constant humidity conditions and have
at least one half to three fourths of the sample remaining. The samples have been analysed
for total suspended particulates (TSP) and lead (pers. comm. Rob Mitchell, EPA scientist,
2002). The ACWS Input Studies Sub-program 4 obtained approval to use one third of these
samples to analyse for rates of dryfall for a range of elements.
Existing dust sample data were compiled on mass per volume over the years of record and
this data was evaluated to arrive at yearly average particulate masses collected as well as to
identify dust storm events. Selected samples were acid digested and analysed using ICP­
AES (inductively coupled plasma atomic emission spectrometry) by CSIRO Energy
Technology, Lucas Heights, in order to determine the concentration of major and trace
elements (Appendix II). Forty one bulked samples were analysed by ICP-AES. Samples
were bulked in three month groupings: Jan.-Feb.-March; April-May-June; July-AugustSeptember; October-November-December. Elements obtained are presented in Appendix
III. Quarterly bulked samples were used in order to provide an indication of seasonal
variation and variation from year to year as well as having the advantage of diminishing
sample to sample variation in load collected on each individual filter. Each bulked composite
sample comprised between 10 and 15 sub-samples. In addition to the ambient sampling
filters, high dust concentration event filters were selected and analysed. In addition to the
ICP-AES analyses, the filters were analysed for total Kjeldahl nitrogen (TKN).
Only eight years of actual filters were available, therefore it was not possible to investigate
dust composition over as long a period as originally intended.
Rainfall samples were collected by an automated sampler that was installed at the Adelaide
Airport for the purposes of this study. Samples were analysed for a variety of nutrients
including nitrogen species (NO2, NO3, NH3), carbon species (total, inorganic and total
organic), and phosphorus species (dissolved, soluble and reactive). The sampler collected
rainfall through the wet season of 2004 and several events in early 2005. Samples were
analysed in the Environmental Health Laboratory at Flinders University.
The overall nitrogen loading by wetfall to the entire coastal zone was calculated by summing
each sample volume and its concentration to yield a total average load for all data points at
the sampling location. The overall load throughout the coastal zone was estimated by the
technique of grouping the coastline into 5 km wide east-west strips extending 10 km off­
shore. Loads were calculated on the basis of the percent urbanised area in each strip and
weighting the loading to each strip accordingly. The Adelaide airshed was defined as an
area 115 km by 60 km wide, centred on the urbanised metropolitan area between the
Adelaide Hills and the coast.
The overall load to the 10 km wide strip from the coastline out into Gulf St Vincent from
Gawler River to Sellicks Creek was calculated by summing the load in each strip. A value of
85 µg N/L was used as the un-urbanised background concentration based on the lowest five
percentile concentration measured during onshore storms when maximum washout had
already occurred. This background concentration results in a load of 1.65 g N/m2/y.
Dryfall TKN was estimated using the same approach as for wetfall nitrogen. Literature
values of the deposition rate were the basis for the calculations and were between 1.7 and
3.4 kg N/ha/y, to give an upper and lower estimate.
Adelaide Coastal Waters Study Technical Report No. 17
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4.
Results
4.1
Wetfall and Dryfall Nitrogen Load
Total Wetfall N (Tonnes)
The wetfall nitrogen deposition for 2004 to a 10-km-wide strip of the ACWS coastline from
the Gawler River to Sellicks Beach was estimated at approximately 33 tonnes.
The total load of wetfall nitrogen to the coastal zone based on the measured concentrations
and calculated loads totals 32.8 tonnes with a maximum loading of 8.1 kg N/ha/y (wetfall).
The loading follows an expected pattern based-on the extent of urbanised area. The
maximum urban loading above an assumed ambient loading in the central zone is 6.5 kg
N/ha/y.
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
Sector 12 = Airport Wetfall Collector
Urban Loading
Background
1
2
3
4
5
Total N Load for 10 km strip:
32.8 Tonnes
6
7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22
Coastal Sector, Gawler to Sellicks Beach
Figure 2. Total load of nitrogen from wetfall across 5 km strips along the coastal zone in
Adelaide. There was 213 GL of direct rainfall during the 2004/5 hydrological year.
Dryfall TKN was estimated at between 800 and 1600 kg/y to the 10 km coastal strip. The
EPA has estimated dryfall oxides of nitrogen at 40 tonnes/y to a 2 km strip between the Light
River and Marino (M. Hartley, EPA, pers comm., 2005). The EPA estimates used the TAPM
air quality model which gives a range of deposition rates ranging from approximately 0.3 kg
N/ha/yr in the off-shore zone to 8 kg N/ha/y adjacent to major sources of NOx such as the
Pelican Point power plant. The mean deposition rate for the 2 km wide strip was 2.9 kg
N/ha/y. For dryfall TKN the mean deposition rate was 0.016 kg N/ha/y, similar to that
estimated for Chicago by Lestari et al. (2003). This lower mean is not surprising given that
the estimation strip extends 10 km off-shore. The Pelican Point power plant emission was
not included in the TKN estimate. As can be seen in the maps in Appendix VIII Pelican Point
power plant dominates the deposition of dry NOx in the Barker Inlet area. Elsewhere the
deposition rate is significantly lower.
In summary, the dry TKN load is approximately 1.6 tonnes into 1050 km2 and the EPA 2 km
strip NOx deposition is 40 tonnes into 142 km2. Assuming a deposition rate of approximately
0.5 kg N/ha/y NOx to the remaining 908 km2, an additional 45 tonnes per year NOx would
be deposited into the off-shore part of the 10 km strip. This brings the estimated total
nitrogen to the coastal zone to approximately 86 tonnes a year. This figure approaches the
total input of stormwater nitrogen and is less than a tenth of the load from waste-water
treatment plant discharges.
The omission of the Pelican Point power plant discharge from the estimate of wetfall
nitrogen, undoubtedly results in an underestimation of nitrogen from wetfall and it is possible
that there may be in excess of 20 tonnes wetfall NOx annually in the vicinity of the power
plant.
Adelaide Coastal Waters Study Technical Report No. 17
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4.2
Wetfall, Washout and Individual Rainfall Events
Of the carbon, nitrogen and phosphorus measured in rainfall at Adelaide Airport, carbon was
in the highest concentration with total carbon at 2.55 mg/L (Table 1). Organic carbon was
the largest subset of the total carbon. The geometric mean of the total nitrogen results was
only 0.275 mg/L, and ammonia nitrogen was generally the largest component of the nitrogen
(Table 1, Figure 3); 60% by concentration for the whole dataset. Phosphorus was only
present at concentrations of a few tens of micrograms per litre.
Table 1. Wetfall carbon, nitrogen and phosphorus concentrations from the automatic rainfall
sampler sited at Adelaide Airport.
The maximum concentration of nitrogen was somewhat greater than 2.5 mg TN/L. In
general, ammoniacal nitrogen was a large component of the high TN results, however, there
were a number of events that had high TN that were almost entirely oxidised nitrogen. The
reason for this is not clear, these events do not correlate with wind direction or other
variables.
Summarising the wetfall nitrogen data into monthly mean concentrations and total loads
demonstrates that, for the 2004-5 rainfall season, oxides of nitrogen are the dominant
components of the total nitrogen concentration from March to the end of May (Figure 4).
From June onwards into the wet season, the mean monthly total nitrogen concentration is
significantly lower and ammonia nitrogen is the dominant form of nitrogen. An obvious
interpretation of these results is that, during late summer and Autumn, air pollution sources
of nitrogen are dominant. Then, with the wetting of soils and streams, microbial ammonia
sources become dominant.
Adelaide Coastal Waters Study Technical Report No. 17
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2500
Total Nitrogen (mg/L)
NOx_N, 37.2%
2000
1500
NH3_N, 62.8%
High NOx events
1000
500
0
Figure 3. Rainwater samples ranked by total nitrogen concentration showing the proportion
of oxidised and reduced nitrogen species.
An examination of wind speed and direction associated with the antecedent period for each
rainfall event offers no surprises in the interpretation of the monthly mean nitrogen
concentration and load (Figure 4). Greater rain totals are associated with stronger westerly
winds whereas easterly light winds with less rain are associated with lower nitrogen loads. In
2004, there was a tendency for winds to go from southerly to northerly as the season
progressed.
Figure 4 gives a false indication that there was no rain between from October to March
2004/5. This was not the case. It was simply that the events that did occur were small and
infrequent and hence did not result in sufficient liquid volume to analyse. The use of a bulk
rainfall collector in tandem with the automatic rainfall sampler would have been valuable.
This would have made analysis for metals feasible, as it was there was rarely sufficient
liquid volume to run the analyses. In addition, some measure of total ionic strength such as
electrical conductivity would have been informative to identify marine influence in the
collected wetfall.
A useful outcome of the automatic rainfall collector was that it was possible to investigate
washout events following periods of dry weather. These demonstrate the accumulation of
nutrients and total carbon in the atmosphere and their subsequent washout during rainfall
events. Figures 5 and 6 show two washout events, one from early, and one from the middle
of the wet season. White bars on upper graph represent duration over which samples were
bulked (Figures 5 and 6). Note the high levels of nitrogen and carbon species in the first
parts of the rainfall events (Figure 5). In the June event (Figure 6), the overall levels of
nitrogen and carbon species were lower compared to the March event, yet washout of
nitrogen and carbon still occurred.
The return to elevated concentrations of nutrients and total carbon was relatively rapid (a
day or two), and occurred during the wet season and after early wet season storms. An
examination of nitrogen concentrations and antecedent dry days demonstrated some
confirmation of a build-up washout process (Figure 7). A moderate correlation between
antecedent dry time greater than 12 hours and nitrogen concentration was found (Figure 7).
This pattern exists for total nitrogen, nitrate and ammonia. Thus, from a minimum of twelve
hours, the concentration of nitrogen species increases with increasing antecedent dry time.
Adelaide Coastal Waters Study Technical Report No. 17
6
Rainfall Total
(mm)
0
50
Rainfall
Wind Strength
(m/s)
1
Wind
Strength
20
0
1 = westerly, 0 = easterly
Westerly
1 = northerly, 0 = southerly
Northerly
0.5
0
1.5
1
0.5
0
8000
NH3N
6000
NOxN
4000
2000
0
1000
750
NH3N
500
NOxN
250
December
November
October
September
August
July
June
May
April
March
February
0
January
Nitrogen concentration (ug/L)
Nitrogen Load (kg)
40
Wind Tendency Wind Tendency
100
Figure 4. Seasonal variation in total rainfall, mean wind strength and wind direction at
Adelaide Airport, nitrogen load for the 10-km coastal strip and, nitrogen concentration at
Adelaide Airport.
Adelaide Coastal Waters Study Technical Report No. 17
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Adelaide Coastal Waters Study Technical Report No. 17
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M a r c h 2 8 e v e n t: An t. D r y d a ys 1 9
4.5
4
3.5
3
2.5
2
1.5
1
0.5
0
M arch 28 e v e nt
1400
1200
1000
800
600
400
200
0
TC
NO3
IC
NH3
TO C
Time (hours)
Figure 5. Hydrograph and corresponding analyses of precipitation event March 28, 2004.
J u n e 1 2 -1 6 E v e n t: A n t. D r y d a y s 0
4
3 .5
3
2 .5
2
1 .5
1
0 .5
0
J u n e 1 2 -1 6 E v e n t
1400
1200
1000
800
600
TC
NO3
NH3
400
IC
TO C
200
0
Figure 6. Hydrograph and corresponding analyses of precipitation events over June 12-16,
2004.
8
10000
10000
0.7857
y = 62.126x
2
R = 0.0828
1000
Total Nitrogen (ug/L)
Total Nitrogen (ug/L)
0.0906
100
y = 12.485x
2
R = 0.762
1000
12 hr < T < 400 hr
All Data
100
10
0.0
913
1553
0.1
1.0
10
100.0 1000.0 10000.
0
Time between events (hours)
144
10.0
1000
10000
10000
0.7694
y = 8.4793x
2
R = 0.6835
1.1569
y = 0.6897x
2
R = 0.7067
1000
NH3_N (ug/L)
NO3_N (ug/L)
100
Time between events (hours)
100
1000
100
70 < [NH3_N]
12 hr < T < 400 hr
12 hr < T < 400 hr
10
10
10
100
1000
Time between events (hours)
10
100
1000
Time between events (hours)
Figure 7. Correlation plots for antecedent dry days between rainfall events and nitrogen
species.
4.3
Dryfall Particulate Matter
Total suspended particulates and PM10 (particulate matter that passes through a 10 µm
filter) collected by the high volume air sampler at Osborne were found to be highly variable
(Figure 8). Overall seasonal variation and day-to-day variation in dust concentration is
apparent from both Figure 8 and 9. Over the eight years and 350 days of high volume data
available for the Osborne station, the low reading was 3.6 µg/m3, high reading was 263
µg/m3, with an average of 57 µg/m3 (standard deviation of 49 µg/m3). Thus, the high dust
days had only 2-5 times the average dust concentration, less than anticipated. In fact, low
dust days (< 10 µg/m3) are five times lower than the average. These data support the overall
view of the Adelaide area being a moderately to strongly, windy and dusty place. The dust
concentration data when analysed with the rainfall data illustrate the well-known process of
washout of dust and aerosols by rainfall. In addition, the dust concentration data and rain
wash-out data show that in the Adelaide metropolitan area, dust levels require only a few
days of dry weather to get back to average and even above average levels.
Adelaide Coastal Waters Study Technical Report No. 17
9
Osborne/2000
160.0
140.0
120.0
ug/M3
100.0
TSP
80.0
TSP-PM10
60.0
40.0
20.0
09/09/2000
26/08/2000
12/08/2000
29/07/2000
15/07/2000
01/07/2000
17/06/2000
03/06/2000
20/05/2000
06/05/2000
22/04/2000
08/04/2000
25/03/2000
11/03/2000
26/02/2000
12/02/2000
29/01/2000
15/01/2000
01/01/2000
0.0
Figure 8. An example of a dust year for the station at Osborne (near Port Adelaide). As
expected, the PM10 concentrations are much less than the TSP, although at some low
concentrations the two measurements approach similar values.
TSP-95-avg/month
140.0
120.0
100.0
TSP-95-avg/month
TSP-96-avg/m
TSP-97
80.0
ug/M3
TSP-98
TSP-99
TSP-00
60.0
TSP-01
TSP-02
TSP-03
40.0
20.0
0.0
Jan-95
Feb-95
Mar-95
Apr-95
May-95
Jun-95
Jul-95
Aug-95 Sep-95
Oct-95
Nov-95
Dec-95
Figure 9. Plot of monthly averaged high-volume filter data over the years from 1995-2003.
Data illustrate the rough seasonal pattern of lower TSP during wet winter months and higher
TSP during drier months.
The annual load of atmospheric particulate matter deposited into the 10 km coastal strip was
estimated at between 1,800 and 3,860 tonnes. This assumed a peak deposition rate of
between 215 kg/ha/y and 450 kg/ha/y. The deposition rates assumed mean settling velocity
of between 0.012 and 0.025 m/s and mean TSP of 57 µg/m3. The mean deposition rate over
the entire 10 km coastal strip was 36 kg/ha/y.
Adelaide Coastal Waters Study Technical Report No. 17
10
4.4
High-volume Sampler Particulate TKN
The high-volume sampler filters were analysed for a wide range of elements by ICP-AES, in
addition analysis for TKN nitrogen was undertaken. Appendix III provides the analytical
results and the calculated concentrations of TKN in ambient air and total particulates
collected on the Osborne sampler filters. The TKN values were estimated for three, 4-month
periods covering each year of the approximately 8-year period of record. Table 2
summarises the mean, maximum and minimum TKN concentrations in the analytical digest
solution, air passed through the filters and on the particulates collected by the filters. As
discussed in Section 4.5 below, the variability of the blank unexposed filters over time is not
known. There were two results of greater than 0.05 µg/m3 in the period from late 2001 to
2004, these include around 20 filters each and span a four month period. The surrounding
results are around the mean concentration, it seems possible that these results may
represent early summer and late summer dust storms in 2001 and 2003.
Table 2. Basic descriptive statistics for TKN concentration of digested filters, ambient air and
particulates collected on the filters.
n
Mean
Min
Max
4.5
TKN analysis result
(blank corrected) Average TKN in air Average TKN on
mg/L
ug/m3
particulates mg/g
22
22
22
0.196
0.025
0.446
0.100
0.011
0.238
0.350
0.057
1.383
High-volume Sampling Particulate Composition
An examination of the content of a wide range of major and trace elements in particulates
collected by the high volume air sampler at Osborne indicates a number of major changes in
composition. These are:
• Increased sulfur content;
• reduced lead;
• reduced trace element concentrations, and;
• three grouped periods of self consistent composition.
Interpretation of the high-volume filter analytical results was severely hampered by the lack
of representative blank filters for analysis. The filters were sourced from different suppliers
during the period of use of the samplers. The change in suppliers meant that the elemental
composition of the filters changed with each new supply of filters. The composition of the
filters was not of significance for the original EPA study which was intended to examine
PM10 particulates and total suspended particulates (TSP) and lead concentration. It was not
anticipated that the filters would be of such variable quality and contain high concentrations
of a wide range of elements.
Adelaide Coastal Waters Study Technical Report No. 17
11
Na
Ca
100.000
1.000
0.100
0.001
Blank
Mean exposed filters
90 Zr
0.010
95 Mo
78 Se
163 Dy
118 Sn
238 U
45 Sc
59 Co
157 Gd
172 Yb
111 Cd
166 Er
147 Sm
153 Eu
141 Pr
133 Cs
107 Ag
159 Tb
121 Sb
209 Bi
169 Tm
175 Lu
182 W
195 Pt
232 Th
205 Tl
105 Pd
9 Be
93 Nb
202 Hg
Cr
10.000
Pb
208 Pb
47 Ti
63 Cu
85 Rb
Mn
60 Ni
7 Li
127 I
140 Ce
51 V
139 La
146 Nd
75 As
1000.000
69 Ga
P
88 Sr
Concentration in digested filter (mg/g)
10000.000
Mg
B
K
Al
S
137 Ba
Zn
Fe
100000.000
0.000
Figure 10. Comparison of elemental concentrations in blank and exposed filters.
The implications of the changes in filter composition did not become fully apparent until after
the laboratory analyses were completed. The consequence of the changing filter
composition is that three distinct compositional groups are apparent in the analytical results
for the digested exposed filters. Since the composition of the blank filters used to correct the
results was not specifically chosen to match the batch of exposed filters for each subsample and hence bulked filter digest, it is almost impossible to separate the filter
composition offset of the results from the true composition of the particulate matter collected.
Figure 10 charts the concentration of each element analysed in the blank and the mean of
the exposed filters, the results are expressed as the proportion of the digested filter mass.
Appendix IV presents all of the raw data for each element with the blank value. Even if it had
it been known that the filter composition would vary so greatly, there was insufficient
unexposed filter material available to provide representative individual blanks for each filter
sub-sample, and if there had been, the need to run tandem blanks for each bulked digest of
sub-samples would have halved the number of results analysed because of the available
analysis budget.
Since the data were exhaustively investigated in order to assess whether some useful or
informative outcome could be attained, the observations made are presented below. In
Appendix V the elements that are auto-correlated are plotted on the same axis to
demonstrating which elements co-vary and their relative abundance.
Should additional funding and sufficient contemporary blank filter material be sourced it is
possible that appropriate blank assays might be carried-out to allow the current results to be
corrected and the true patterns of abundance and variability of the elemental composition of
the collected high volume air sampler particulates be revealed.
The elements Na, Ca, Mg, B, K, Al, Cu, Cr, Rb, Li, As, Se, Be, Ba, Zn, Ga and Eu appear to
have been most strongly influenced by the changes in filter composition. For this reason
these elements are not discussed below. In addition, various other variables were eliminated
from the analysis on the basis of the elevated blank concentration. These were Pt, Pd, W
and Zr. The loss of platinum from the analysis was unfortunate because Pt is an important
component of roadside dust (Batley, pers. comm.) A range of the other elements were
clearly influenced by the filter compositional variation (Figure 11), and others show no
apparent variation with the filters (TSP, Fe, Mn, Sr, Ti, Bi) (Figure 12).
Adelaide Coastal Waters Study Technical Report No. 17
12
Mass on one filter (ug)
10000.0
137 Ba
Data Point 1 = Blank
Zn
1000.0
69 Ga
153 Eu
100.0
10.0
1.0
0.1
0.0
1
2
3
5
7
9
11 13 15 17 19 21 23 25 27 29 31 33 35 37 Figure 11. Variation in concentration of four variables clearly influenced by the major
variations in filter composition, in this case the result for the exposed filter was less than the
blank.
The results presented below summarise the investigation of the elements whose
concentration was significantly higher than the blank and that were less affected by the
changes in composition of the unexposed filters. Appendix VI summarises the mean
concentrations in air and particulates for these elements.
Figure 13 demonstrates the inter-elemental relationships between the particulates on high
volume air sampler filter papers by presenting multiple X-Y scatter plots of the data. The
plots demonstrate certain correlations in the elements present. The strongest relationships
are between the lanthanide elements, atomic numbers 57 to 70. These elements form two
closely correlated groups:
• Lanthanum, cerium, praseodymium, neodymium, promethium and samarium;
and
• Terbium, dysprosium, erbium, thulium, ytterbium and lutetium.
1000000
Mass
(TSP)
Mass on one filter (ug)
100000
Fe
10000
1000
Mn
100
88 Sr
10
47 Ti
1
0.1
209 Bi
0.01
1.
1
3
5
7
9
11
13
15
17
19
21
23
25
27
29
31
33
Figure 12. Elements that co-vary with total suspended particulates and show no long term
trend (data point 1 is the blank).
Adelaide Coastal Waters Study Technical Report No. 17
13
Figure 13. Inter-elemental composition of constituents of particulates collected by the highvolume air sampler at Osborne, Metropolitan Adelaide. “Dust” represents the concentration
of particulates in µg/m3 of air sampled.
The elements in these groups correlate very closely (r2 > 0.92) and the two groups have
been represented by dysprosium and neodymium which cross-correlate most strongly within
their respective groups (see Appendix VII).
While discussing the lanthanides, it is worth noting that previous studies have used the
ratios of lanthanides, lanthanum and cerium in atmospheric samples (e.g. Kitto et al., 1992;
Wilkinson et al., 1997) as a tracer. Ratios of La:Ce ≈ 1 are indicative of a petrochemical
catalytic cracking agents used in the refining of oil products. In the current study the ratio of
La:Ce in solids collected on the high volume air samplers varied from 0.41 to 0.56 (mean
0.457), this is consistent with a crustal source (Table 3, Figure 14).
Adelaide Coastal Waters Study Technical Report No. 17
14
Table 3. Sources and ratios of Lanthanum and Cerium
Source
Ratio La:Ce
Reference
Particulates on high volume air
filters: Adelaide
Earths crust
Marine shale
Bermuda aerosol
Soil and road dust (Japan)
Mineral monazite
Coal-fired power station (US)
0.457 (0.41 – 0.56)
Current study
0.50 ± 0.04
0.49 (0.39 – 0.52)
0.454
0.45 (0.25 – 0.68)
0.51
0.51 ± 0.04
Olmez and Gordon (1985)
Sholkovitz (1990)
Sholkovitz (1990)
Mizohata (1986)
Mizohata (1986)
Mizohata (1986)
18
Lanthanum (ug/g)
16
14
12
10
8
y = 0.4555x
6
R2 = 0.9252
4
2
5
15
25
35
Cerium (ug/g)
Figure 14. Correlation of lanthanum and cerium in particulates collected on high volume air
sampler filters at Osborne between 1995 and 2004.
The apparent variation in trace element content of the particulates was used to partition the
data and highlighted both the three compositional blocks of time during which the elemental
composition remained consistent and the dramatic change between blocks (associated with
the change in the blank filter composition). The use of a multiple-scatter was highly effective
in demonstrating the major variations in elemental composition. An initial interpretation of the
data was that the differing compositional relationships were a consequence of air masses of
differing sources, however, an examination of the data tables indicated sharp transitions in
discrete blocks. This demonstrates the value of multiple visualisation techniques in
investigating large datasets relating to environmental variables (also used by Wilkinson et
al., 1997; 2005).
Adelaide Coastal Waters Study Technical Report No. 17
15
50
.12
20
Particulate matter g/m3
Iron mg/g
Sulphur mg/g
18
9
.10
40
16
.08
30
14
.06
12
20
.04
N=
2.5
9
11
12
1
2
3
FE
8
0.00
0
S
DUST_AIR
10
10
.02
N=
3.5
EPOCH2
Phosphorus mg/g
9
11
11
1
2
3
EPOCH2
N=
20
Lead mg/g
3.0
9
11
12
1
2
3
EPOC H2
EPOCH2
Lanthanum ug/g
18
2.0
16
2.5
14
2.0
1.5
6
12
1.5
10
1.0
1.0
6
.5
6
9
11
12
1
2
3
4
LA
P
N=
PB
0.0
31
0.0
-.5
N=
EPOCH2
9
11
12
1
2
3
2
N=
EPOCH2
5
Dysprosium ug/g
4
8
.5
.7
Samarium ug/g
5
9
11
12
1
2
3
EPOC H2
EPOCH2
Mercury ug/g
.6
4
4
.5
3
3
.4
34
2
.3
2
34
4
1
34
.2
4
1
N=
6
.1
9
11
12
1
2
3
HG
39
SM
DY
0
-1
0
N=
EPOCH2
9
11
12
1
2
3
0.0
N=
10 EPOCH2
3.5
Thorium mg/g
9
11
12
1
2
3
EPOCH2
Caesium mg/g
5
Uranium mg/g
3.0
1
10
8
4
2.5
20
6
21
3
2.0
2
34
2
1.5
4
4
15
1
1.0
2
.5
-1
N=
EPOCH2
9
11
12
1
2
3
30
28
0
U
CS
TH
0
N=
9
11
12
1
2
3
EPOCH2
0.0
N=
9
11
12
1
2
3
EPOCH2
Figure 15. Box and whisker plots demonstrating changes in the elemental content of
particulates collected from ambient air by the high-volume sampler sited at Osborne,
Metropolitan Adelaide.
The three periods between which significant compositional variations were found are:
(i)
January 1995 to end August 1997;
(ii)
September 1997 to end May 2000; and
(iii)
September 2000 to end august 2004.
During periods (i) and (ii) the concentration of lead is still elevated, in period iii the lead
concentration is low as are many of the other trace element concentrations. It is not clear
Adelaide Coastal Waters Study Technical Report No. 17
16
whether this reduction in purely associated with the changing filter composition of the
reduction in lead.
The later period (iii) samples in Figure 13 have blue coloured markers. Period (i) data points
have red markers and period ii data and marked green. As can be seen, the period (i) and
period (ii) data are quite distinct in their trace element composition. Figure 15 represents the
same three blocks of samples with box and whisker plots for data on a various elements.
In Figure 13 the plot of neodymium (ND) and dysprosium (DY) demonstrates that the two
groups of lanthanides were present in different ratios. This difference was what highlighted
the block composition of particulates. In period i the lighter lanthanides (atomic numbers 41
to 62) represented by ND were present in higher proportion than the heavier ones (atomic
numbers 65 to 71) represented by DY. In period (ii) the opposite was the case. In period iii,
the lanthanides and many of the other trace elements as well as minor elements were
significantly reduced.
0.70
Jan'95 to Sept'97
Lutetium (ug/g)
0.60
Sept'97 to Jun'00
0.50
Jun'00 to Sept'04
0.40
0.30
0.20
0.10
Recent low Lead samples
0.00
0
1000
2000
3000
4000
Lead (ug/g)
Figure 16. Relationship between lead and the trace element lutetium in particulates
collected by the high volume air sampler at Osborne.
The box and whisker plots of Figure 15 indicate this very clearly. Although many of the trace
elements undergo major reductions in concentration from periods (i )and (ii) to period (iii),
the actual particulate concentration per cubic metre of air sampled did not fall. The fact that
the dust concentration in the air did not fall but the reduction in trace element concentrations
coincided with the elimination of lead could mean that the removal of lead in petrol has also
reduced many other elements that were associated with lead.
In addition to the differing lanthanide composition of periods (i) and (ii), Figure 15
demonstrates that the changes in the thorium and uranium concentrations coincide with the
variation in the lanthanides. Uranium was elevated in period ii along with the DY heavier
lanthanides. Conversely, thorium was elevated in period (i) and significantly lower in period
(ii) and (iii).
Adelaide Coastal Waters Study Technical Report No. 17
17
160
TSP in Air (ug/m3)
140
120
100
Osborne
Port Adelaide
Thebarton
80
60
40
20
3/
12
/0
125
1/
/2
6/
/0
02
2
2
4/
6/
12
8/
/0
02
226
2/
/2
6/
/0
03
3
-3
5/
1/
12
8/
/0
03
327
2/
/2
6/
/0
04
4
-3
1/
8/
04
3/
1/
95
-2
6/
2/
2/
6/
95
95
31
5/
/8
12
/9
/9
5
627
2/
/2
6/
/9
96
6
-3
5/
1/
12
8/
/9
96
627
3/
/2
6/
/9
97
7
-2
6/
6/
12
8/
/9
97
728
4/
/2
6/
/9
98
8
2
1/
7/
12
8/
/9
98
823
5/
/2
6/
/9
99
9
-2
2/
8/
12
8
/9
/9
9
924
/2
/0
0
0
800
Lead in Air (ng/m3)
700
600
500
Osborne
Port Adelaide
Thebarton
400
300
200
100
3/
12
/0
125
1/
/2
6/
/0
02
2
26
4/
/8
12
/0
/0
2
226
2/
/
2
6/
/
0
03
3
-3
5/
1/
12
8/
/0
03
327
2/
/2
6/
/
04
04
-3
1/
8/
04
3/
1/
95
-2
6/
2/
2/
6/
95
95
-3
5/
1
/8
12
/9
/9
5
627
2/
/
2/
6/
96
96
-3
5/
1/
12
8
/9
/9
6
627
3/
/2
6/
/
9
97
7
-2
6/
6/
12
8/
/9
97
728
4/
/2
6/
/
98
98
-2
1/
7/
12
8
/9
/9
8
823
5/
/2
6/
/
9
99
9
-2
2/
8/
12
8/
/9
99
924
/2
/0
0
0
Figure 17. Quarterly TSP and lead in air sampled at Osborne, Port Adelaide and Thebarton.
Figure 17 demonstrates the dramatic reduction in lead concentration in ambient air at
Osborne, Port Adelaide and Thebarton. Thebarton is in an area of far greater traffic
movement and hence had a much higher initial lead concentration. By 2002, the
concentration of lead in air at Thebarton was approximately the same as that at Osborne.
Figure 16 further demonstrates the periods of differing composition, and highlights that
recent low lead results were also low in trace elements (the blue points in Figure 13 above).
Again, to reiterate from above, this may be significant if it demonstrates that the trace
elements were associated with lead. It is certainly nothing new to report reduced lead in air.
This has been known for some time and the elimination of lead in petrol was prompted by
health studies of the impact of lead on the development of children.
Figure 18 shows the gradual change-over in sales of leaded petrol to un-leaded petrol in
Australia from 1986 to 2004. For the period over which high volume filters were analysed,
1995 to 2004, the reduction in lead concentration is clear (Figure 19). The reduction in the
lead concentration in particulates in ambient air at Osborne indicated by the data analysed
for this report is greater than 82%. The reduction in the concentrations of a suite of minor
and trace elements (Figure 19), these include antimony, tin, silver, mercury and various
others may be associated with the decline in the use of lead.
Adelaide Coastal Waters Study Technical Report No. 17
18
Australian Petrol Usage (kBl)
20000
18000
16000
Leaded (-92%)
Unleaded (+88%)
14000
12000
10000
8000
6000
4000
2000
0
1986 1988 1990 1992 1994 1996 1998 2000 2002 2004
Figure 18. The reduction in sales of leaded petrol in Australia from 1987 to 2002 (data from
Australian Institute of Petroleum).
If there has been a genuine reduction in the concentrations of these other contaminants at
the same time as the removal of lead this must be beneficial since these elements would not
have been present in such high concentrations prior to European settlement.
The surprising corollary of the reduction of lead in petrol is that the concentration of lead in
stormwater has also declined significantly (see Wilkinson et al., 2005). The percentage
change in the central metropolitan creeks range from a 65 to 83% reduction in median lead
concentrations from the peak annual median for each site, for the available record.
Figure 19 demonstrates the relative abundance of the measured analytes in filtered
particulates from the Osborne high-volume sampler. The data are presented on a log10 yaxis, this makes it possible to see the concentrations of the trace elements and allows a
comparison of the relative increase or reduction in concentration. Sulfur, TKN and iron are
three of the larger constituents of particulates that were analysed for. Lead and phosphorus
were two of the other constituents in larger proportion until recent times (Table 4).
Of the constituents that appear to have reduced at the same time as lead, there is P, Sn, Sb
and Hg. Silver had also reduced in concentration, however, as indicated in Appendix V there
appear to have been a number of extreme silver events that resulted in the elevated means
in periods i and ii. Certain of the elements/constituents appear to have increased in
concentration, for example S, TKN, Cu, Ni, As, Se and Be. The reason for this is not clear
and while many of these elements are in concentrations greater than the blanks analysed, in
the absence of representative blanks, it is still unclear whether the increases are genuine or
simply due to the filter composition variations.
Sulfur presents an interesting case. Sulfur is greater in the later air samples. Is this due to a
deterioration in fuel quality as a consequence of elevated sulfur in petroleum products, or is
it simply representative of a decay mechanism whereby sulfur on the stored high volume
papers has been sequestered away?
Adelaide Coastal Waters Study Technical Report No. 17
19
100000.000
S, 90.1%, 29091
Period i (Jan'95 to end Aug'97)
Period ii (Sept'97 to end Aug'00)
Fe, -22.7%, 11557
TKN, 48.3%, 556
P, -65.6%, 467
Mn, -7.3%, 305
Sr, 18.1%, 255
Ti, 56.6%, 244
Pb, -85.4%, 222
Cu, 84.7%, 140
I, 148.7%, 45.7
V, 46.6%, 42.8
Ni, 219.0%, 37.8
As, 203.2%, 17.8
Ce, -44.7%, 15.8
Co, 76.6%, 10.47
Nd, -45.2%, 8.09
La, -49.4%, 7.13
Se, 568.5%, 6.02
Mo, -33.1%, 4.83
Cd, -27.3%, 3.07
Pr, -44.1%, 2.21
Sm, -51.3%, 1.56
Be, 123.8%, 1.410
Gd, -56.8%, 1.34
Cs, -59.5%, 1.34
Bi, -13.0%, 1.037
U, -50.6%, 0.861
Th, -78.6%, 0.839
Ag, -81.7%, 0.808
Dy, -75.8%, 0.790
Sn, -87.4%, 0.727
Tl, -42.7%, 0.675
Er, -84.9%, 0.445
Sb, -64.9%, 0.407
Yb, -92.1%, 0.216
Tb, -68.2%, 0.156
Nb, -66.9%, 0.141
Hg, -62.5%, 0.128
Lu, -87.6%, 0.049
Tm, -90.7%, 0.042
10000.000
Lead
Period iii (Sept'00 to end
Aug'04)
Mean Concentration (ug/g)
1000.000
100.000
10.000
1.000
0.100
0.010
0.001
Figure 19. Relative abundance of analytes in high-volume air sampling particulates,
showing the mean concentration of period iii and maximum percentage change between the
grouped periods; period (i) (January 1995 to end August 1997), period (ii) (September 1997
to May 2000) and, period (iii) (September 2000 to end August 2004).
Figure 20 demonstrates the seasonal variation in TSP and lead. The particulate
concentration is lowest during the winter months (June to the end of August).
The lead concentration on the particulates was highest during the winter. This was probably
due to there being less particulate matter to adsorb to, but the same degree of motoring
activity and hence the same amount of lead available in the air. There was also more lead
per cubic metre of air sampled during the winter. This may have been related to the lack of
particulates which would have reduced the scavenging of lead from the atmosphere and
subsequent settling-out. Put another way, the exhaust fume and associated lead would hang
in the air for longer. This effect is likely to have been exacerbated by inversion conditions
trapping exhaust fume rich air in a shallow layer of a few tens of metres above the ground.
Clearly these data present some interesting puzzles that might be worthy of further
investigation, however, for the purposes of the current study these matters remain
supplementary to the project objective and any further investigation might be done within a
student dissertation if funding to analyse representative blanks is available.
Adelaide Coastal Waters Study Technical Report No. 17
20
Table 4. The concentration of each element whose exposed filter analytical results were
significantly greater than the blank for three periods associated with changes in filter
composition and reduced lead.
Valid
N
Mean
(ug/g)
Valid
N
Mean
(ug/g)
Valid
N
%
change
Period iii
Mean
(ug/g)
S
Fe
TKN
Pb
P
Mn
Sr
Ti
Cu
V
Ce
I
Nd
La
Ni
Mo
Co
As
Sn
Ag
Th
Pr
Cd
Cs
Sm
Gd
Dy
Er
Tl
U
Sb
Bi
Yb
Se
Be
Nb
Hg
Tb
Tm
Lu
Period ii
Valid
N
Particulates
(mg/m3)
Total
Particulates (g)
Period i
Mean
(ug/g)
All values
0.0572
N=32
0.0529
N=9
0.0624
N=11
0.0557
N=12
18.0
1.593
21333
12839
523
778
808
313
237
244
119
38.9
23.7
38.9
12.12
10.80
26.0
5.33
7.67
14.7
2.179
1.87
1.904
3.29
3.00
2.08
2.49
2.23
1.901
1.580
0.840
1.253
0.678
1.020
1.306
4.05
1.139
0.284
0.206
0.309
0.222
0.197
N=32
N=31
N=32
N=22
N=32
N=32
N=32
N=32
N=32
N=32
N=32
N=32
N=32
N=32
N=32
N=32
N=32
N=32
N=32
N=32
N=32
N=32
N=32
N=32
N=32
N=32
N=32
N=32
N=32
N=31
N=32
N=32
N=32
N=32
N=32
N=32
N=32
N=32
N=32
N=32
N=32
1.548
15300
14943
463
1523
1356
329
239
186
76
29.2
28.5
19.1
14.25
14.09
11.9
6.88
6.07
6.0
5.769
4.408
3.928
3.91
3.47
3.30
2.86
2.35
1.708
1.419
1.178
1.177
1.160
1.088
1.032
0.90
0.630
0.426
0.341
0.292
0.181
0.155
N=9
N=9
N=9
N=5
N=9
N=9
N=9
N=9
N=9
N=9
N=9
N=9
N=9
N=9
N=9
N=9
N=9
N=9
N=9
N=9
N=9
N=9
N=9
N=9
N=9
N=9
N=9
N=9
N=9
N=9
N=9
N=9
N=9
N=9
N=9
N=9
N=9
N=9
N=9
N=9
N=9
1.701
18510
12517
476
776
731
309
216
291
131
42.6
28.5
47.6
14.77
12.12
24.8
4.60
5.93
18.3
0.824
0.953
1.411
3.96
2.52
1.90
3.19
3.11
3.271
2.949
0.734
1.743
0.579
0.947
2.719
4.46
1.261
0.326
0.182
0.49
0.453
0.394
N=11
N=11
N=11
N=8
N=11
N=11
N=11
N=11
N=11
N=11
N=11
N=11
N=11
N=11
N=11
N=11
N=11
N=11
N=11
N=11
N=11
N=11
N=11
N=11
N=11
N=11
N=11
N=11
N=11
N=10
N=11
N=11
N=11
N=11
N=11
N=11
N=11
N=11
N=11
N=11
N=11
1.528
29091
11557
615
222
467
305
255
244
140
42.8
15.8
45.7
8.09
7.13
37.8
4.83
10.47
17.8
0.727
0.808
0.839
2.21
3.07
1.34
1.56
1.34
0.790
0.445
0.675
0.861
0.407
1.037
0.216
6.02
1.410
0.141
0.128
0.156
0.042
0.049
N=12
N=11
N=12
N=8
N=12
N=12
N=12
N=12
N=12
N=12
N=12
N=12
N=12
N=12
N=12
N=12
N=12
N=12
N=12
N=12
N=12
N=12
N=12
N=12
N=12
N=12
N=12
N=12
N=12
N=12
N=12
N=12
N=12
N=12
N=12
N=12
N=12
N=12
N=12
N=12
N=12
-10.2
90.1
-22.7
32.8
-85.4
-65.6
-7.3
18.1
56.6
84.7
46.6
-44.7
148.7
-45.2
-49.4
219.0
-33.1
76.6
203.2
-87.4
-81.7
-78.6
-44.1
-27.3
-59.5
-51.3
-56.8
-75.8
-84.9
-42.7
-50.6
-64.9
-13.0
-92.1
568.5
123.8
-66.9
-62.5
-68.2
-90.7
-87.6
Adelaide Coastal Waters Study Technical Report No. 17
21
summer
Particulates mg/m3
0.12
autumn
0.10
winter
0.08
spring
0.06
0.04
0.02
Particulates
0.00
1994 1996
1998 2000 2002
2004 2006
summer
3.5
autumn
Lead mg/g
3
winter
2.5
spring
2
1.5
1
0.5
Lead
0
1994
1996
1998
2000
2002
2004
2006
summer
0.10
autumn
Lead mg/m3
0.08
winter
spring
0.06
0.04
0.02
Lead
0.00
1994 1996 1998
2000 2002 2004 2006
Figure 20. Changes in lead concentration of air and filtered particulates from 1994 to 2004
showing seasonal differences.
Adelaide Coastal Waters Study Technical Report No. 17
22
5.
Conclusions
The wetfall and dryfall contribution of nitrogen input to the Adelaide Coastal Waters is a
minor component of the overall load (less than 1% of the total or about 33 tonnes/y) and is
about the same as stormwater flows. This low loading is due to the low concentrations in
rainwater and particulate matter of nitrogen and other pollutants. Dryfall contributes a
significant amount to the total solids (approximately 18%), however again the concentration
of nitrogen and other pollutants is low. With the gradual reduction of lead in the air due to
unleaded petrol over the last 15 years, lead input has declined significantly. Nitrogen
species washed out in rainwater are dominated by oxidised nitrogen (NOx) during the
summer and autumn, presumably from fossil fuel burning sources. During the winter wet
season, reduced ammonia nitrogen dominates the washout. Dusty wind events do not
contribute much greater loads than background dust and wind conditions. Dust and
pollutants in the atmosphere are quickly returned to background levels after only a day or
two following washout events (rain). However, generally, the longer the dry period prior to a
rainfall event, the higher the concentration of dust and pollutants will be.
Adelaide Coastal Waters Study Technical Report No. 17
23
6.
References
Busacca, A., Wagoner L., Mehringer, Jr., P., and Bacon, M., (Barber. 2000. African Dust
and the Demise of Caribbean Coral Reefs. Geophysical
Research Letters. 27(19), p. 3029-3032.
Busacca, A., et al., 1998). Effect of human activity on dustfall: a 1,300-year lake core record
of dust deposition on the Columbia Plateau, Pacific Northwest U.S.A.. p. 8-11. In A.J.
Busacca (ed.) Dust Aerosols, Loess Soils, and Global Change. College of Agriculture
and Home Economics Miscellaneous Publication MISC0190, Washington State
University, Pullman, WA.
Castro, M.S., and Driscoll, C.T. (2002). Atmospheric nitrogen deposition to estuaries in the
mid-Atlantic and northeastern United States. Environmental Science Technology, 26,
3242-3249.
Clark, R.D.S. (1987). Nitrogen and phosphorus in rainwater at locations near Adelaide,
South Australia: unpublished technical report for the Engineering and Water Supply
Department, South Australian Government, 44 p.
Darwin, C. (1846). An account of the fine dust which often falls on vessels in the Atlantic
Ocean. Quarterly Journal of the Geological Society of London, v. 2, p. 26-30.
Kayaalp, A.S. (2001). Application of rainfall chemistry and isotope data to hydrometeological modelling: unpublished Ph.D. thesis Flinders University, 273 p.
Kitto, M.E., Anderson, D.L., Gordon, G.E., and Olmez, I. (1992). Rare earth distributions in
catalysts and airborne particles. Environ. Sci. Technol., 26, 1368-1375.
Lestari, P., Oskouie, A.K., Noll, K.E. (2003). Size distribution and dry deposition of
particulate mass, sulphate and nitrate in an urban area. Atmospheric Environment 37,
2507-2516.
Mizohata, A.J. (1986). Rare earth elements in atmospheric particles and their sources. J.
Aerosol Res. Japan, 1, 966-968.
Nakamura, T., Matsumoto, K., Uematsu, M. (2005). Chemical characteristics of aerosols
transported from Asia to the East China Sea: an evaluation of anthropogenic
combined nitrogen deposition in autumn. Atmos. Environ. 39, 1749-1758.
National Pollutant Inventory Summary Report of Fourth Year Data 2001-2002: Environment
Australia; www.npi.gov..au.
Olmez, I. and Gordon, G.E. (1985). Rare earths: Atmospheric signatures for oil-fired power
plants and refineries. Science 229, 966-968.
Paramee, S. Chidthaisong, A., Towprayoon, S., Asnachinda, P., Bashkin, V.N., Tangtham,
N., 2005: Three-year monitoring results of nitrate and ammonium wet deposition in
Thailand DE nitrate, ammonium, wet deposition, Thailand: Environmental Monitoring
and Assessment, 102, 27-40.
Adelaide Coastal Waters Study Technical Report No. 17
24
Poor, N., Pribble, R., Greening, H. (2001). Direct wet and dry deposition of ammonia, nitric
acid, ammonium and nitrate to the Tampa Bay Estuary, FL, USA. Atmospheric
Environment, 35, 3947-3955.
Prospero, J.M. 1999). Long-term measurements of the transport of African mineral dust to
the southeastern United States: Implications for regional air quality: Journal of
Geophysical Research, 104, 15,917-15,927.
Pye, K. (1987). Aeolian Dust and Dust Deposits: Harcourt Brace Jovanovich, New York.
Shinn, E.A., Smith, G.W., Prospero, J.M., Betzer, P., Hayes, M.L., Garrison, V., and Barber,
R.T. (2000). African dust and the demise of Caribbean Coral Reefs. Geophysical
Research Letters, 27, 3029-3032.
Sholkovitz, E.R. (1990). Rare-earth elements in marine sediments and geochemical
standards. Cheimcal Geology 88, 333-347.
Singer, A., Ganor, E., Dultz, S., and Fischer, W. (2003). Dust deposition over the Dead Sea.
Journal of Arid Environments 53, 41-59.
Wilkinson R.J., Reynolds B., Neal C., Hill S., Neal M. and Harrow M.L. (1997). Major, minor
and trace element composition of cloud water and rainwater at Plynlimon, Mid-Wales.
Hydrology and Earth Systems Sciences (Special Issue: Water Quality of the Plynlimon
Catchments (UK)), 1, 557-570.
Wilkinson J, White, N., Smythe, L., Fallowfield, H., Hutson, J., Bestland, E., Simmons, C.
and Lamontagne, S. (2005). Volumes of inputs, their concentrations and loads
received by Adelaide metropolitan coastal waters. ACWS Technical Report No. 12
prepared for the Adelaide Coastal Waters Study Steering Committee by Flinders
Centre for Coastal and Catchment Environments, Flinders University of SA
September 2005.
Adelaide Coastal Waters Study Technical Report No. 17
25
Appendix I: The Wetfall Collector Located at BOM, Adelaide Airport
Adelaide Coastal Waters Study Technical Report No. 17 26
Adelaide Coastal Waters Study Technical Report No. 17 no air
no air
Vair
Blank
mwhole
Whole
filter
“n” msub-blank
“n” msub
Sub-sample
Vsol
Vsol
Acid
digest
= mg\L
ICP
msub
Vsol
ICP
= mg\L
x Vsol
mdig
mass in
digest
x Vsol
mdig
n
Subtract
blank
me
me-sub-sum
x npapers
:
n
mblank
mass element mass element mass in
subsamples
in one
in one
sum
sub sample
sub sample
from air
:
msam
mass in
whole papers
x mwhole
msub
me-whole
:
Vair
concair
Appendix II: Analysis flow diagram for high volume air sample filter papers.
27
Date range of bulked
filters
TKN analysis result
(Already Blank
Corrected)
Average TKN in air
Average TKN on
particulates
Appendix III: Concentrations of TKN nitrogen collected on high
volume air sampler filters per cubic metre of air sampled and per
gram of particulate matter collected
3/1/95-27/4/95
3/5/95-31/8/95
6/9/95-29/12/95
4/1/96-27/4/96
3/5/96-31/8/96
12/9/96-23/12/96
4/1/97-28/4/97
4/5/97-8/8/97
7/9/97-30/12/97
11/1/98-29/4/98
11/5/98-27/8/98
2/9/98-31/12/98
6/1/99-30/4/99
12/5/99-28/8/99
3/9/99-26/12/99
1/1/00-30/4/00
4/9/01-27/12/01
2/1/02-26/4/02
2/5/02-30/8/02
5/9/02-28/12/02
3/1/03-27/4/03
3/5/03-31/8/03
6/9/03-29/12/03
4/1/04-27/4/04
3/5/04-31/8/04
mg/L
0.26
<0.1
0.15
0.14
0.10
0.19
0.22
<0.1
0.16
0.13
0.14
0.22
0.20
0.18
0.19
0.17
0.35
0.14
0.12
0.18
0.35
0.14
0.28
0.30
<0.1
ug/m3
0.034
mg/g
0.74
Adelaide Coastal Waters Study Technical Report No. 17
0.015
0.015
0.011
0.022
0.023
0.28
0.29
0.32
0.39
0.24
0.021
0.019
0.017
0.020
0.025
0.026
0.037
0.017
0.050
0.024
0.013
0.021
0.057
0.017
0.029
0.031
0.29
0.30
0.43
0.30
0.36
0.76
0.43
0.25
1.38
0.40
0.32
0.37
0.83
0.45
0.40
0.30
28
Appendix IV: Comparison of mass of element in digest of blank and
exposed filters
ug/g
Na
Ca
Mg
B
K
Al
S
Ba
Zn
Fe
Ga
P
Sr
Cr
Pb (OES)
Pb (MS)
Ti
Cu
Rb
Mn
Ni
Li
I
Ce
V
Nd
La
As
Mo
Parts per million of digested filter matrix
Mean
exposed
Blank
filters
ug/g
Blank
41000
36900
Zr
0.056
6970
8182
Se
0.039
2380
2220
Dy
0.039
2200
1650
Sn
0.036
1270
1300
U
0.036
1070
1102
Sc
0.033
292
931
Co
0.032
229
239
Gd
0.032
161
176
Yb
0.028
53.3
457
Cd
0.027
19.0
12.8
Er
0.026
5.44
30.6
Sm
0.024
3.28
10.3
Eu
0.019
3.01
4.37
Pr
0.018
2.46
23.7
Cs
0.016
2.20
24.7
Ag
0.008
2.00
9.82
Tb
0.006
1.51
4.91
Bi
0.005
1.21
1.66
Sb
0.005
0.754
10.4
Tm
0.005
0.721
1.43
Lu
0.004
0.590
0.859
W
0.002
0.557
1.61
Pt
0.002
0.118
0.874
Th
0.001
0.102
1.27
Tl
0.001
0.072
0.455
Pd
0.000
0.072
0.413
Be
0.000
0.062
0.463
Nb
0.000
0.056
0.206
Hg -0.001
Adelaide Coastal Waters Study Technical Report No. 17
Mean
exposed
filters
0.002
0.153
0.100
0.094
0.076
0.050
0.271
0.103
0.069
0.108
0.076
0.103
0.032
0.122
0.079
0.064
0.016
0.036
0.024
0.012
0.010
0.003
0.002
0.064
0.029
0.008
0.033
0.009
0.005
29
Appendix V: Mass of element in digest of exposed filters
300000
10000.0
9000.0
8000.0
7000.0
6000.0
5000.0
4000.0
3000.0
2000.0
1000.0
0.0
250000
Mass (ug)
200000
150000
100000
50000
Bl
A u an k
tu
m
n
'95
Sp
rin
g'
95
W
in
te
r'
9
Au
6
tu
m
n
'97
Sp
rin
g'
97
Au
tu
m
n
'98
Sp
rin
g'
98
Au
tu
m
n
'99
Sp
rin
g'
99
Au
tu
m
n
'
00
Su
m
m
er
'01
W
in
te
r'
01
Su
m
m
er
'02
W
in
te
r'
02
Su
m
m
er
'03
W
in
te
r'
03
Su
m
m
er
'04
W
in
te
r'
04
0
Mass (TSP)
Mass 2 (filter + elements)
Mass 2 (minus Na, Ca, Mg, B, K, Al, S, Cu, Cr, Rb, Li, As, Se, Be, Ba, Zn, Ga and Eu[2nd y-axis])
1.
ICP Concentration (ug/L)
1000000.0
Na
Data Point 1 = Blank
Ca
Mg
B
100000.0
K
Al
S
10000.0
1000.0
1
1.1
3
5
7
9
11
13
15
17
19
21
23
25
27
29
31
33
35
37
ICP Concentration (ug/L)
100.0
63 Cu
Cr
85 Rb
7 Li
75 As
78 Se
9 Be
10.0
1.0
0.1
Data Point 1 = Blank
0.0
1
1.2
3
5
7
9
11
13
ICP Concentration (ug/L)
10000.0
15
17
19
21
23
25
27
29
31
33
35
37
137 Ba
Zn
69 Ga
153 Eu
Data Point 1 = Blank
1000.0
100.0
10.0
1.0
0.1
0.0
2
1
3
5
7
9
11
13
15
17
19
21
Adelaide Coastal Waters Study Technical Report No. 17
23
25
27
29
31
33
35
37
30
10.0
ICP Concentration (ug/L)
Data Point 1 = Blank
1.0
0.1
0.0
1
3
3
5
7
9
11
13
15
17
19
21
23
25
27
29
31
33
35
37
Fe
P
Mn
88 Sr
47 Ti
202 Hg
10000.0
ICP Concentration (ug/L)
140 Ce
146 Nd
139 La
141 Pr
147 Sm
157 Gd
163 Dy
238 U
166 Er
172 Yb
45 Sc
159 Tb
169 Tm
175 Lu
93 Nb
1000.0
100.0
10.0
1.0
0.1
0.0
Data Point 1 = Blank
0.0
0.0
1
4
3
5
7
9
11
13
15
17
19
21
23
25
27
29
31
33
35
37
10.0
ICP Concentration (ug/L)
Data Point 1 = Blank
118 Sn
232 Th
1.0
0.1
0.0
0.0
0.0
1
5
3
5
7
9
11
13
15
10.0
19
21
23
25
27
29
31
33
35
37
107 Ag
Data Point 1 = Blank
ICP Concentration (ug/L)
17
107 Ag
1.0
0.1
0.0
1
3
5
7
9
11
13
15
17
19
21
Adelaide Coastal Waters Study Technical Report No. 17
23
25
27
29
31
33
35
37
31
ICP Concentration (ug/L)
100.0
127 I
60 Ni
51 V
10.0
1.0
Data Point 1 = Blank
0.1
1
8
3
5
7
9
11
13
15
17
19
21
23
25
27
29
31
33
35
37
ICP Concentration (ug/L)
1.0
209 Bi
205 Tl
0.1
0.0
Data Point 1 = Blank
0.0
1
9
3
5
7
9
11
13
15
17
19
21
23
25
27
29
31
33
35
37
10.0
59 Co
95 Mo
133 Cs
121 Sb
ICP Concentration (ug/L)
Data Point 1 = Blank
1.0
0.1
0.0
1
10
3
5
7
9
11
13
15
17
19
21
23
25
27
29
31
33
35
37
ICP Concentration (ug/L)
1000.0
208 Pb
111 Cd
195 Pt
100.0
10.0
Data Point 1 = Blank
1.0
0.1
0.0
0.0
11
1
3
5
7
9
11
13
15
17
19
Adelaide Coastal Waters Study Technical Report No. 17 21
23
25
27
29
31
33
35
37
32
Appendix VI: Mean concentrations of elements analysed for in high
volume air samples.
Element
32 S
56 Fe
31 P
207 Pb
55 Mn
47 Ti
88 Sr
63 Cu
51 V
127 I
60 Ni
140 Ce
75 As
146 Nd
139 La
59 Co
95 Mo
78 Se
141 Pr
111 Cd
147 Sm
157 Gd
118 Sn
133 Cs
163 Dy
232 Th
107 Ag
166 Er
172 Yb
238 U
9 Be
209 Bi
205 Tl
121 Sb
159 Tb
93 Nb
169 Tm
202 Hg
175 Lu
Concentration in Particulates
ug/g
21845.554
12644.135
786.530
739.784
305.399
240.235
231.807
113.951
37.742
36.975
25.229
23.211
14.103
11.845
10.575
7.440
5.170
3.842
3.220
2.922
2.437
2.179
2.048
2.043
1.844
1.828
1.780
1.518
1.252
1.226
1.094
0.990
0.930
0.646
0.301
0.277
0.213
0.197
0.189
Adelaide Coastal Waters Study Technical Report No. 17
Concentration in Air
ng/m3
1224.905
1008.184
57.053
38.769
21.860
19.194
16.165
7.017
2.621
2.038
1.632
1.796
0.848
0.901
0.808
0.531
0.333
0.215
0.247
0.194
0.189
0.166
0.097
0.149
0.135
0.127
0.103
0.102
0.083
0.097
0.068
0.067
0.062
0.037
0.023
0.020
0.014
0.011
0.012
33
Appendix VII: Multiple scatter plots of minor and trace elements in
Adelaide high volume air samples.
Figure AVII.1. Inter-elemental relationships of log10 transformed concentrations of minor and
trace elements in solids collected on filter papers from air passing through high volume
samplers (excluding the actinides and lanthanides).
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34
Figure AVII.2. Multiple scatter plots of log10 transformed concentrations of lanthanides and
actinides in solids on high volume air sampling filter papers (values not shown are in ng/g
solids).
Adelaide Coastal Waters Study Technical Report No. 17
35
Appendix VIII: Dry deposition of nitrogen species to the central and
northern Adelaide Metropolitan Area and 2km buffer strip for estimating N load
(prepared by M. Hartley, South Australian EPA).
Figure AVIII.1. Dry nitrogen dioxide deposition to Adelaide Coastal Waters in tonnes per
year, 2002.
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Figure AVIII.2. Dry deposition total nitrogen oxides to Adelaide Coastal Waters in tonnes/y,
2002.
Adelaide Coastal Waters Study Technical Report No. 17 37
Figure AVIII.3. The buffer strip used to estimate the dry nitrogen oxide load to the
immediate coastal strip.
Adelaide Coastal Waters Study Technical Report No. 17 38