To elucidate contamination by persistent organic pollutants POPs—including dichloro-diphenyl-tri-chloroethane and its metabolites DDTs, hexachlorocyclo-hexanes HCHs, chlordanes, hexach
Trang 1Contamination by Persistent Organic Pollutants in Dumping Sites of Asian
Developing Countries: Implication of Emerging Pollution Sources
N H Minh,1T B Minh,1N Kajiwara,1T Kunisue,1A Subramanian,1H Iwata,1T S Tana,2
R Baburajendran,3S Karuppiah,3P H Viet,4B C Tuyen,5S Tanabe1
1Center for Marine Environmental Studies, Ehime University (CMES), Bunkyo-cho 2-5, Matsuyama 790-8577, Japan
2Social and Cultural Observation Unit, Cabinet of the Council of Minister, Phnom Penh, Cambodia
3Centre of Advanced Study in Marine Biology, Annamalai University, Annamalai Nagar, 608 002, India
4
Centre for Environmental Technology and Sustainable Development, Hanoi National University, Hanoi, Vietnam
5
Nong Lam University, Hochiminh, Vietnam
Received: 7 April 2005 /Accepted: 15 August 2005
Abstract In Asian developing countries, large amounts of
municipal wastes are dumped daily in open dumping sites
without proper management This practice may cause several
adverse environmental consequences and increased health risk
to local communities To elucidate contamination by persistent
organic pollutants (POPs)—including
dichloro-diphenyl-tri-chloroethane and its metabolites (DDTs),
hexachlorocyclo-hexanes (HCHs), chlordanes, hexachlorobenzene (HCB), and
polychlorinated biphenyls (PCBs)—in such dumping sites, soil
samples were collected from open dumping sites and
respec-tive control sites in Cambodia, India, and Vietnam from 1999
through 2001 Our results demonstrated that DDTs, PCBs, and
HCHs were dominant contaminants in the dumping sites.
However, the contamination pattern was not consistent,
showing higher HCHs in India than in Cambodia and Vietnam.
Interestingly, in all of the countries, extremely higher levels of
POPs were observed in the dumping sites compared with those
in the respective control sites, suggesting significant
amplifi-cation of POP contamination in the dumping sites of Asian
developing countries Mean concentrations of DDTs and PCBs
were 350 and 140 ng/g dry weight, respectively, in the
dumping sites of Cambodia and 26 and 210 ng/g, respectively,
in India These residue levels were hundreds to thousands
times higher than those in general soils, implying possible risk
to human health of the local communities, especially to the rag
pickers, including children who work in these sites to collect
recyclable materials Composition of DDT compounds
sug-gested their recent use in populated areas, which in turn might
have caused increased levels of DDTs in the open dumping
sites In addition, composition of HCH isomers revealed their
different use pattern in different countries.
During the past few decades, several persistent organic
pollu-tants (POPs), including polychlorinated biphenyls (PCBs) and
organochlorine pesticides (OCPs), were used extensively in Asian developing countries for industry, agriculture, and vector control Available data demonstrated approximately 4.9 million tons of hexachlorocyclohexanes (HCHs) and 400 thousand tons
of dichloro-diphenyl-trichloroethane and its metabolites (DDTs) were produced in China between the 1950s and 1980s, accounting for 33% and 20% of world production, respectively (Zhang et al 2002) In India, annual consumption of pesticides
is approximately 85,000 metric tons, of which DDTs, HCHs, and malathion accounted for 70% (Gupta 2004) In other countries such as Vietnam, use of OCPs—including DDTs, HCHs, etc., continued until 1995 (Sinh et al 1999) Persistence
of such chemicals in soils, air, and water, together with natural processes such as evaporation to the atmosphere and washout
by rain and flood, give rise to their ubiquitous distribution in the environment and eventual penetration into food chains and bioaccumulate in humans Public concern about contamination
by POPs increased recently because several of these com-pounds are identified as hormone disrupters, which can alter normal function of endocrine and reproductive systems in hu-mans and wildlife (Cheek et al 1999; Colborn et al 1993; Kelce 1995; Vos et al 2000) Recognition of these conse-quences has led to the international restriction and ban on 12 POPs, including dioxins, PCBs, and several OCPs, to limit their harmful impacts on global environment and human health (Anonymous 2001).
Although prohibitions on uses of POPs have been imple-mented in developed nations, a number of them are still in use
in Asian developing countries For instance, recent input of DDTs to environment has been recorded constantly in China, India, and Vietnam (Minh et al 2002; Monirith et al 2003; Nakata et al 2004) Because of the ability of POPs to undergo long-range transport, their continuous use in Asian developing countries may cause contamination in other parts of the globe
as well, even in pristine areas such as the Arctic and Antarctic.
In addition, recycling of POPs from contaminated soils into the atmosphere is another pollution source to the global environ-ment (Harner et al 2001) All of these facts may further
Correspondence to:S Tanabe; email: shinsuke@agr.ehime-u.ac.jp
DOI: 10.1007/s00244-005-1087-3
Trang 2support the previous assumption that contamination by POPs
still remains a critical environmental issue in Asian developing
countries (Tanabe 2002).
In Asian developing countries, because of the lack of
ad-vanced facilities, large amounts of municipal wastes from
populated areas are directly dumped into open dumping sites
with very poor management This practice raises public
con-cern over potential harmful effects to local communities and
the environment These concerns probably become more
pragmatic when recent intensive studies demonstrated
in-creased human health risk caused by exposure to toxic
chemicals, such as dioxins and related compounds, and heavy
metals in these dumping sites (Minh et al 2003; Agusa et al.
2003) Given that several POPs have been used extensively for
various purposes in Asian developing countries, their increased
contamination in these open dumping sites is likely However,
no comprehensive study so far has examined potential sources
of POPs pollution as well as their effects to the environment
and human health In this study, we report, for the first time,
increased contamination by several POPs, such as PCBs,
DDTs, HCHs, HCB, and CHLs (chlordane-related
com-pounds), in dumping sites from Asian developing countries,
suggesting open dumping sites as significant pollution sources
of POPs in the region.
Materials and Methods
Sample Collection
Soil samples were collected from some municipal dumping sites in
Hanoi and Hochiminh (Vietnam), Chennai (India), and Phnom Penh
(Cambodia) from 1999 through 2001 Urban or agricultural soils
were also collected in appropriate sites that were at least
approxi-mately 30 km far away from any dumping site and hereafter
re-ferred as control samples relative to the dumping soil samples
Locations and major characteristics of dumping and control sites are
shown in Figure 1 In general, the open dumping sites were located
close to human habitats, and many people work in the dumping
sites of Cambodia and India to collect reusable materials Soil
samples were collected at depths from 0 to 10 cm at five points
with an area of approximately 25 m2, combined together, and
considered as a representative sample Soils were kept in clean
plastic bags, maintained at 4C, transported to our laboratory in
Japan, and stored at –20C until chemical analysis
Analytic Method
POPs in soil samples were analyzed according to the method
de-scribed by Iwata et al (1994) with some modifications Briefly, 15
ml hexane-washed water followed by 100 ml acetone was added to
a conical flask containing 15 g air-dried soil The flask was shaken
vigorously for 60 minutes in an electric shaker, and soil solution
was filtered into a separating funnel containing 600 ml
hexane-washed water and 100 ml hexane The funnel was shaken for 15
minutes and kept in a stand for at least 8 hours to entirely separate
the aqueous from the hexane layers The aqueous layer was
dis-charged, and the hexane layer was washed three times with 100 ml
water times Hexane volume in the final solution was measured for
calculating recovery from the initial 100 ml and then concentrated
by Kuderna-Danish (KD) apparatus to approximately 10 ml and
further blown down by nitrogen stream to 5 ml This 5-ml solution
was transferred to a multilayer column packed with silica gel,
H2SO4-absorbed silica gel, and AgNO3-absorbed silica gel Three layers in the column was packed in the following order: 0.5 g silica gel, 2 g H2SO4-absorbed silica gel, 0.5 g silica gel, 2 g AgNO3 -absorbed silica gel and, finally, 0.5 g Na2SO4 After transferring the samples into the multilayer column, the elution was made by passing 250 ml 5% dichloromethane in hexane through the column The collected mixture was concentrated by KD and blown down by nitrogen to exactly 5 ml Hexane-washed water was added to wash this 5 ml solution three time Four ml of this solution was collected
by pipette for further cleanup by gel-permeation chromatography and separated by Florisil (Wako Chemicals USA) chromatography column to obtain PCB and OCP fractions as previously described (Minh et al 2003) The final solution was further concentrated, if necessary, before instrumental analysis PCBs, DDTs, HCHs, CHLs, and HCB were quantified by gas chromatography (GC)–electron-capture detection (ECD) (Agilent 6890N) using DB-1 fused silica capillary column (30 m · 0.25 mm i.d · 0.25-lm film thickness) The column oven temperature was programmed from 60C (1 minute) to 160C at a rate of 20C/min, held for 10 minutes, then increased to 260C at a rate of 2C/min, and held for 20 minutes The PCB standard used for quantification was a mixture of 62 PCB congeners (Wellington, Ontario, Canada) Concentrations of indi-vidually resolved peaks of PCB isomers and congeners were sum-med to obtain total PCB concentrations Recovery rates obtained by this procedure were as follows: HCHs 85% to 91%; HCB 91%; PCBs 108%; CHLs 87% to 98%, and DDTs 82% to 103% A procedural blank was run for every batch of five samples for cross-verification
Statistical Analysis
The statistical analysis was performed with StatView Version 5 software (SAS, Cary, NC) SpearmanÕs rank correlation test was used
to examine significance of correlation between residue levels of the contaminants
Results and Discussion
Residue Levels and Contamination Pattern of POPs in the Dumping Sites
In general, DDTs and PCBs were found in high levels in dumping sites of Vietnam, India, and Cambodia (Table 1) Contamination pattern of POPs in Cambodia and Vietnam followed the order of DDTs > PCBs > HCHs > CHLs > HCB In contrast, the pattern in India revealed higher levels of HCHs than DDTs (PCBs > HCHs > DDTs > CHLs > HCB) The difference in such patterns indicates more extensive use of HCHs in India compared with Cambodia and Vietnam The residue patterns in our study highlighted contamination by DDTs, PCBs, and HCHs in Asian developing countries
Concentrations of PCBs and DDTs in dumping site soils varied largely with their highest concentrations found in Chennai and Phnom Penh, respectively (Table 1) Interestingly, levels of PCBs and DDTs
in all the dumping sites were higher than those in the respective control sites, implying their increased contamination in such dumping sites However, the extent of difference between residue levels in the dumping site soils and the control soils also varied in different countries Although in India and Cambodia, PCBs and DDTs con-centrations in the dumping site soils were hundreds to thousands of times higher than their control soils, in Vietnam this difference was not very high, suggesting larger amplification of the contamination in the dumping sites of India and Cambodia compared with Vietnam
Trang 3Particularly, DDTs levels in Cambodian dumping sites were >15
times higher than the other dumping sites and 300 times higher
compared with the respective control sites Heavy dumping in the
relatively small area of dumping sites in Cambodia (Minh et al 2003)
might have led to the higher concentrations of DDTs in this area It is
noteworthy that Monirith et al (2003) reported low levels of DDTs in
mussels collected from coastal areas of Cambodia In this context,
such highly contaminated dumping sites in Cambodia would be of
particular concern as they become pollution sources of DDTs to the
environment and biota During the sampling surveys, we observed a
large number of local people working in such dumping sites to collect
reusable waste Therefore, the increased contamination by POPs such
as PCBs and DDTs in Indian and Cambodian dumping site soils may
increase toxic exposure and cause health risks to the local
commu-nities, especially rag pickers
In contrast to the ranking of PCBs and DDTs in the dumping site
soils, residue levels in the control soils of such countries followed the
opposite pattern, showing the highest concentration in Vietnam
fol-lowed by Cambodia and India (Table 1) In fact, higher
concentra-tions of PCBs and DDTs in mussels, birds, and human breast milk
collected from Vietnam compared with other Asian developing
countries were also reported in previous studies (Monirith et al 2003;
Minh et al 2002; Minh et al 2004) In Vietnam, likely source of
PCBs could be releases from old electric capacitors and transformers,
which were imported into Vietnam until the mid-1980s (Sinh et al
1999) In addition, additional sources of PCBs might relate to
dif-ferent kinds of military heavy weapons used extensively during the
Vietnam War as suggested earlier (Thao et al 1993) Similarly, more
intensive use of DDT in past decades in Vietnam probably caused
higher background levels in the environment as well as food chains
In Asian developing countries, DDT has been used extensively for
both agriculture and vector control during the last few decades
(Tanabe et al 1994) Although its application in agriculture is now
officially prohibited in most of the countries, the use for vector control
is allowed to continue in some countries such as India, China,
Thailand, Myanmar, etc (Anonymous 2001) This could be a
plausible reason for relatively higher DDTs levels in urban compared
with rural areas (Minh et al 2001; Nhan et al 2001; Phuong et al
1998) Continuous application of DDT in highly populated areas for
vector control and other hygienic purposes might have led to the presence of DDTs in municipal waste Accumulating such garbage in small areas such as open dumping sites in turn might have amplified the levels of DDTs in soil
In global comparison, PCBs levels in dumping site soils were com-pared with those in general soils worldwide, including industrial coun-tries, which are known to have higher background levels of PCBs (Breivik et al 2002; Meijer et al 2003) In general, PCB levels in the global background soils were considerably lower than those in the dumping site soils of India and Cambodia and slightly lower than those
of Vietnam (Table 2) This fact again highlighted the importance of open dumping sites as pollution sources of PCBs in Asian developing coun-tries Moreover, increased concentrations of PCBs in our sampling sites under tropical conditions may enhance their recycling from soil to atmosphere and undergoing long-range atmospheric transport to reach regions at higher latitudes (Wania and Mackay 1996) In this context, large number of open dumping sites in Asian developing countries may
be important sources of such chemicals to the global environment As a consequence of insufficient management in the open dumping sites, PCBs may again escape from these sites to contaminate the local envi-ronment and pose health risks to local communities
DDT concentrations in dumping sites of Asian developing countries were higher than urban soils from many locations over the world (Ta-ble 2) DDT levels in dumping sites were probably higher or compa-rable with those in agricultural soils collected in the early 1990s from areas with intensive application of DDT such as the United States, Argentina, and Russia It should be emphasized that although DDTs are
no longer used in some regions such as North America and Europe, their re-emission from DDT-contaminated soils still remains as an important source of DDTs to the atmosphere, making them available for long-range transport to remote areas such as the Arctic region (Harner et al 2001) In this aspect, emerging pollution sources of DDTs in Asian developing countries may not be only an environmental issue for the region but also a concern for the global environment
Mean concentrations of HCHs, CHLs, and HCB were rather low compared with DDTs and PCBs, except in India However, their levels in dumping-site soils were also higher compared with those in control soils Particularly, HCH levels in the Indian dumping-site soils were much higher than those in control soils (Table 1) as well as other Fig 1 Sampling locations in Vietnam, Cambodia, and India
Trang 4Table 1 Concentration (ng/g dry weight) of POPsain dumping-site and control-site soils from Asian developing countries
Vietnam, Hanoi (DS)
Vietnam, Hanoi (CS)
Vietnam, Hochiminh (DS)
Vietnam, Hochiminh (CS)
India, Chennai (DS)
India, Chennai (CS)
Cambodia, Phnom Pen (DS)
Cambodia, Phnom Penh (CS)
aHCHs = a–HCH + b–HCH + c–HCH: DDTs = p,p¢-DDE + p,p¢-DDD; + p,p¢-DDT; CHLs = trans-chlordane + cis-chlordane + trans-nonachlor + cis-nonachlor
bWhen results were less than quantification limits, the limits were inserted to calculate means
CHLs - Chlordanes
CS - Control site soil
DDTs - Dichloro-diphenyl-trichloro ethanes
DS - Dumping-site soil
HCHs – Hexachlorocyclohexanes
NQ - Not quantified because of large interfering peaks
Trang 5countriesÕ soils in the global comparison (Table 2) This result implied
extreme contamination by HCHs in Indian dumping sites
HCH technical mixtures have been produced and used largely in
India until very recently, leading to increased HCH levels in various
environmental media (Pandit et al 2001; Bhattacharya et al 2003;
Monirith et al 2003) Kannan et al (1995) stated that 1 million tons
of HCHs were used in India during 1948 through 1995 However, it
should be noted that in the tropical atmosphere of India, HCH isomers
exhibited very short half-lives in agricultural soils, varying between
10 and 30 days (Samuel et al 1991; Tanabe et al 1991)
Conse-quently, increased residue levels of HCHs found in the dumping site
of Chennai may reflect current use of a significant amount of HCHs
Moreover, the fast disappearance of HCHs in the Indian soils did not
necessarily mean they were highly degraded Approximately 90% of
their residues evaporated into the atmosphere (Tanabe et al 1991) In
dumping sites, increased levels of HCHs in soil may likely cause
disequilibrium in the air–soil interface, thus favoring their emission
from the soil In view of the global environment, HCHs evaporated
from dumping sites would increase their availability for long-range
atmospheric transport to remote areas (Wania and Mackay 1996)
For CHLs, although their major application in the Asian
devel-oping countries are not very clear (Iwata et al 1994), Monirith et
al (2003) observed relatively higher CHLs residues in mussels from
highly populated areas, from industrial areas, and, especially, from
fishing harbors The investigators therefore suggested use of CHLs
against termites as a likely source of CHLs to those environments
In contrast, HCB was used in the Asian developing countries as
fungicide in the past In addition, it should be noted that some of
the HCB in the environment would be byproduct discharged during
production as well as use of several agrochemicals and industrial
substances (Macdonald et al 2000; Monirith et al 2003)
Composition of POPs in Dumping Site Soils
Figure 2 shows the comparison of DDT composition in dumping site
soils from three countries The proportion of p,p¢-DDT in dumping site
soils ranged from 18% to 38% on average, with the highest value found in the dumping site of India Interestingly, p,p¢-DDT proportion (Fig 3) and the ratio of p,p¢-DDT to p,p¢-DDE (data not shown) were higher in dumping site compared with control soils, implying recent input of the parent compound into dumping sites Considering that the control sites were usually located in agricultural areas, these results may strengthen the recent findings that DDT was perhaps mainly used for hygienic purposes and vector control rather than for agriculture in recent years (Minh et al 2004; Monirith et al 2003; Nhan et al 2001)
Available data demonstrated that DDT levels in general soils col-lected from Hanoi in 1992 were several times higher than present levels (Table 2; Thao et al 1993) In addition, the proportion of p,p¢-DDT in the soils collected in 1992 was also twice those in 2000 (70% and 30%, respectively) This observation probably indicates decreasing application of DDT in the Hanoi area In contrast, in Chennai (India), DDT level in general soils from the late 1980s were from 1 to 6 ng/g with an average p,p¢-DDT proportion of 33% (Ra-mesh et al 1991), which is comparable with the present data from the Chennai dumping site (Table 1)
Composition of HCH isomers varied among the dumping-site soils (Fig 3), showing higher c-HCH in Hanoi and lower values in Chennai, reflecting differences in their use patterns Because lin-dane contains mostly c-HCH and although the technical mixture has more a-HCH, the pattern found in Hanoi soils suggests use of more lindane in this region, whereas patterns in India would provide evidence for predominant use of the technical mixture In our survey on the variation of HCH isomer composition in Hanoi, we found that the proportion of c-HCH increased during the last decade from 23% (Thao et al 1993) to 40% (the present study), probably indicating a shift from primary use of technical mixture to lindane
in the Hanoi region (Fig 3) The dominant presence of c-HCH has also been observed in various environmental matrices in this area, such as surface water (Hung et al 2002) and sediments (Nhan et al 2001) Similar to our results, a study of pine needles from Beijing, China, also observed lower ratios of a-/c-HCH (0.9 to 1.5), revealing increasing recent use of lindane in this country (Xu et al 2004)
Table 2 Global comparison of some POP residue levels (ng/g dry weight) in various soils
aRange is given when mean value is not available
bMedian value
NA - Not available
Trang 6Examining correlations among POPs could be interesting to
understand their accumulation and sources in dumping site soils In
the samples from all dumping sites, DDTs and PCBs were
signifi-cantly correlated (Fig 4), suggesting their similar sources and
accu-mulations in soil Correlations were not significant for other pairs of
POPs, probably because their use pattern was not constant in different
countries
Insight Into Sources of POPs to Dumping Sites
The increased residue levels of DDTs, PCBs, and other POPs found in
open dumping sites were important indications of input and release of
these chemicals The input was believed to involve direct dumping of
municipal and industrial wastes However, some highly contaminated
items may have contributed to a greater extent the increased
con-tamination by POPs than general municipal wastes Such items might
include small equipment, which may contain PCB-containing oils;
industrial wastes from wood-processing factories where OCPs are
heavily used; OCP packing material; and wastes from cleaning small
equipment used to spray the OCPs Other less contaminated items
might consist of house and garden wastes that were contaminated with
OCPs during spray for malaria control campaigns Large residues of the contaminants in such waste ultimately could spread out and thus increase overall concentration in dumping soils
In the present study, no correlation between DDT and PCB residue levels in dumping sites and factors such as daily discharge of municipal wastes (or daily discharge per unit area) and metropolitan population was found However, the lack of such correlations might
be related to the fact that the number of the investigated sites in this study was small and thus insufficient to distinguish the correlations It may also be presumed that such relationships do not exist and that the residue levels of POPs solely depend on random use and discharge of pesticides and other materials in the respective metropolitan area
As for the Stockholm Convention, use of DDT for agricultural purposes was officially banned in most countries in Southeast Asia However, its application for vector control to fight malaria has been allowed in countries such as China, India, Thailand, and Myanmar In addition, illegal use of DDT from remaining local stockpiles can also
be anticipated from other countries in this region According to the International POPs Elimination Network (IPEN 2002), DDT is pro-duced in India and China Hindustan Insecticides Limited is the government-owned company responsible for production in India, and Shenzhen Jiangshan Commerce and Industry Corporation produces
Fig 2 Composition of DDT and its major metabolites in dumping-site soils (DS) and control soils (CS) from Vietnam, Cambodia, and India DDT = dichloro-diphenyl-trichloroethane
Fig 3 Composition of HCH isomers and technical mixtures in soils from Vietnam, Cambodia, and India Data Thao et al (1993)1and
Li et al (1998)2
Trang 7DDT in China Although information regarding exportation of DDT is
not available, DDT production of these companies is thought to be not
only for domestic demand but worldwide demand as well (IPEN
2002)
Continuous input of DDT and its metabolites to the
environ-ment, as well as their bioaccumulation in humans, has been
re-corded in several locations such as China, Cambodia, India,
Thailand, Vietnam, etc (Nakata et al 2005; Xu et al 2004;
Monirith et al 2003; Minh et al 2003; Minh et al 2004 ; Stuetz
et al 2001) A plausible reason for such continuing
contamina-tion claimed in these studies is the legal and illegal use of DDT
It is therefore not surprising that in many recent studies, higher
levels of DDTs are commonly found in highly populated
com-pared with agricultural areas Similar results were also observed
in the present study; furthermore, municipal dumping sites were
also found to be an important emission source of these
con-taminants Another source of DDT to the environment has been
suggested to be recent use of difocol (Kelthane; Dow
Agro-Sciences), a pesticide commonly used for termite control Xu et
al (2004) suggested that use of difocol, which contains 3.5% to
10.8% DDT as byproduct, may be partly responsible for fresh
residues of DDTs in Beijing, China DDT and its metabolites
were also observed in wastewater from dicofol manufacturing
factories (Ormad et al 1997) In Vietnam, dicofol (Kelthane 18.5
emuslfiable concentrate) is on the list of insecticides (Pesticides
Index 2002) Even so, no information is available regarding the
quantity of its recent use in Vietnam In this regard, further
investigations are needed to clarify potential sources of DDTs in
Vietnam, Cambodia, and India so that relevant policies for their
management can be implemented
Conclusion
In this study, we reported for the first time the increased
contamina-tion by POPs—such as DDTs, HCHs, and PCBs—in dumping sites of
Cambodia, India, and Vietnam Similarly, amplified contamination by
POPs could be expected in dumping sites of other Asian developing
countries considering their poor management in municipal wastes and
extensive use of such chemicals in past decades Increased POP levels
in dumping sites are of concern because these sites are located near
human habitats and thus cause higher risk of human exposure to such
toxic chemicals Further studies on redistribution of POPs from
dumping sites to the surrounding environment by way of leaching and
evaporation is necessary to assess their potential harmful effects on
human health and environmental quality
Acknowledgments This study was supported by the Core University Program between Japan Society for the Promotion of Science and National Center for Natural Science and Technology, Vietnam We also acknowledge support from the Research Revolution 2002 (RR 2002) project for Sustainable Coexistence of Human, Nature and the Earth (FY 2002) of the MEXT of the Japanese Government; 21st Century COE Program from MEXT; and Material Cycles Modeling of Persistent Toxic Chemicals and its Policy Research Applications for Recycling and Waste Management from Waste Management Re-search Grants from the Ministry of Environment, Japan
References
Ahmed MT, Ismail SMM, Mabrouk SS (1998) Residues of some chlorinated hydrocarbon pesticides in rainwater, soil and ground water and their influence on some soil microorganisms Environ Int 24:665–670
Agusa T, Kunito T, Nakashima E, Minh TB, Tanabe S, Subramanian
A, et al (2003) Preliminary on trace element contamination in dumping sites of municipal wastes in India and Vietnam J Physique (IV) 107:21–24
Anonymous (2001) Stockholm Convention on Persistent Organic Pollutants Report May 22, 2001
Breivik K, Sweetman A, Pacyna JM, Jones KC (2002) Towards a global historical emission inventory for selected PCB congen-ers—A mass balance approach: Global production and con-sumption Sci Total Environ 290:181–198
Cheek AO, Kow K, Chen J, McLachlan JA (1999) Potential mechanisms
of thyroid disruption in humans—Interaction of organochlorine compounds with thyroid receptor, transthyretin, and thyroid-bind-ing globulin Environ Health Perspect 107:273–278
Colborn T, vom Saal FS, Soto AM (1993) Developmental effects of endocrine-disrupting chemicals in wildlife and humans Environ Health Perspect 101:378–384
Fu J, Mai B, Sheng G, Zhang G, Wang X, Peng P, et al (2003) Persistent organic pollutants in environment of the Pearl River Delta, China: An overview Chemosphere 53:1411–1422 Grath DMC (1995) Organic micropollutant and trace element pollu-tion of Irish soils Sci Total Environ 164:125–133
Gupta PK (2004) Pesticide exposure—Indian scene Toxicology 198:83–90
Harner T, Bidleman T, Jantunen LMM, Mackey D (2001) Soil-air exchange model of persistent pesticides in the United States cotton belt Environ Toxicol Chem 20:1612–1621
Hung DQ, Thiemann W (2002) Contamination by selected chlorinated pesticides in surface waters in Hanoi, Vietnam Chemosphere 47:357–367
Fig 4 Correlation between DDT and PCB concentrations in the dumping-site soils DDT = dichloro-diphenyl-trichloroethane; PCB = polychlorinated biphenyl
Trang 8International POPs Elimination Network (2002) DDT & malaria fact
sheet: Answers to common questions Available at:
http://www.i-pen.ecn.cz or http://www.ipen.org Accessed: August 3, 2005
Iwata H, Tanabe S, Ueda K, Tatsukawa R (1995) Persistent
organo-chlorine residues in air, water, sediments and soils from the lake
Baikal region, Russia Environ Sci Technol 29:792–801
Kelce WR (1995) Persistent DDT metabolite p,p¢-DDE is a potent
androgen receptor antagonist Nature 375(6532): 581–585
Kim JH, Smith A (2001) Distribution of organochlorine pesticides in
soils from South Korea Chemosphere 43:137–140
Kunisue T, Watanabe M, Someya M, Monirith I, Minh TB,
Subra-manian A, et al (2002) PCDDs, PCDFs, PCBs and
organochlo-rine insecticides in human breast milk collected from Asian
developing countries: Risk assessment for infants Organohal
Comp 58:285–287
Li YF, Cai DJ, Singh A (1998) Technical hexachlorocyclohexane use
trends in China and their impact on the environment Arch
Environ Contam Toxicol 35:688–690
MacDonald RW, Barrie LA, Bidleman TF, Diamond ML, Gregor DJ,
et al (2000) Contaminants in the Canadian Arctic: 5 years of
progress in understanding sources, occurrence and pathways Sci
Total Environ 254:193–234
Marta V, Viktor P, Jana K, JNn U (1997) Analytical methods for the
determination of organochlorine compounds—Application to
environmental samples in the Slovak Republic Chromatography
A 774:333–347
Mathur SC (1993) Pesticides industry in India Pestic Inf 19:7–15
Meijer SN, Ockenden WA, Sweetmen A, Breivik K, Grimalt JO,
Jones KC (2003) Global distribution of PCBs and HCB in
background surface soils: Implications for sources and
environ-mental processes Environ Sci Technol 37:667–672
Miglioranza KSB, Moreno JEA, Moreno VJ, Osterrieth ML, Escalate
AH (1999) Fate of organochlorine pesticides in soils and
terres-trial biota of Los Padres pond watershed, Argentina Environ
Pollut 105:91–99
Minh TB, Kunisue T, Yen NTH, Watanabe M, Tanabe S, Hue ND,
Qui V(2002) Persistent organochlorine residues and their
bio-accumulation profiles in resident and migratory birds from North
Vietnam Environ Toxicol Chem 21:2108–2118
Minh NH, Minh TB, Watanabe M, Kunisue T, Monirith I, Tanabe S,
et al (2003) Open dumping site in Asian developing countries: A
potential source of polychlorinated dibenzo-p-dioxins and
poly-chlorinated dibenzofurans Environ Sci Technol 37:1493–1502
Minh NH, Someya M, Minh TB, Kunisue T, Watanabe M, Tanabe S,
et al (2004) Persistent organochlorine residues in human breast
milk from Hanoi and Hochiminh city, Vietnam: Contamination,
accumulation kinetics and risk assessment for infants Environ
Pollut 129:431–441
Monirith I, Ueno D, Takahashi SH, Nakata H, Sudaryanto A,
Subramanian A, et al (2003) Asia-pacific mussel watch:
Moni-toring contamination of persistent organochlorine compounds in
coastal waters of Asian countries Mar Pollut Bull 46:281–300
Nakata H, Hirakawa Y, Kawazoe M, Nakabo T, Arizono K, Abe S,
et al (2005) Concentrations and compositions of organochlorine contaminants in sediments, soils, crustaceans, fishes and birds collected from Lake Tai, Hangzhou Bay and Shanghai city re-gion, China Environ Pollut 133:415–429
Nhan DD, Carvalho FP, Am NM, Tuan NQ, Yen NTH, Villeneuve JP,
et al (2001) Chlorinated pesticides and PCBs in sediments and mollusks from freshwater canals in Hanoi, Vietnam Environ Pollut 112:311–320
Pandit GG, Mohan Rao AM, Jha SK, Krishnamoorthy TM, Kale SP, Raghu K, et al (2001) Monitoring of organochlorine pesticide residues in the Indian marine environment Chemosphere 44:301– 305
Pesticides index (2002 Ministry of Agriculture and Rural Develop-ment of Vietnam, issued March 12, 2002 (in Vietnamese) Phuong PK, Son CP, Sauvain JJ, Tarradellas J (1998) Contamination
by PCBs, DDTs, and heavy metals in sediments of Ho Chi Minh cityÕs canals, Vietnam Bull Environ Contam Toxicol 60:347–354 Rajendran RB, Venugopalan VK, Ramesh R (1999) Pesticide residues
in air from coastal environment, South India Chemosphere 39:1699–1706
Ramesh A, Tanabe S, Murase H, Subramanian AN, Tatsukawa R (1991) Distribution and behaviour of persistent organochlorine insecticides in paddy soil and sediments in the tropical environ-ment: A case study in South India Environ Pollut 74:293–307 Sinh NN, Thuy LTB, Kinh NK, Thang LB (1999) The persistent organic pollutants and their management in Vietnam Pro-ceedings of the Regional Workshop on the Management of Persistent Organic Pollutants—POPs United Nations Environ-ment Programme, Hanoi, Vietnam, March 16–19, 1999, pp 385–406
Stuetz W, Prapamontol T, Erhardt JG, Classen HG (2001) Orga-nochlorine pesticide residues in human milk of a HÕmong hill tribe living in Northern, Thailand Sci Total Environ 273:53–60 Tanabe S (2002) Contamination and toxic effects of persistent endocrine disrupters in marine mammals and birds Mar Pollut Bull 45:69–77
Thao VD, Kawano M, Tatsukawa R (1993) Persistent organochlorines residues in soils from tropical and sub-tropical Asian countries Environ Pollut 81:61–71
Vos JG, Dybing E, Greim HA, Ladefoged A, LambrO C, Tarazona JV,
et al (2000) Health effects of endocrine-disrupting chemicals on wildlife, with special reference to the European situation Critic Rev Toxicol 30:71–133
Xu D, Deng L, Chai Z, Mao X (2004) Organohalogenated compounds
in pine needles from Beijing city, China Chemosphere 57:1343– 1353
Zhang G, Parker A, House A, Mai B, Li X, Kang Y, et al (2002) Sedimentary records of DDT and HCH in the Pearl River Delta, South China Environ Sci Technol 36:3671–3677
Wania F, Mackay D (1996) Tracking the distribution of persistent organic pollutants Environ Sci Technol 30:390A–396A