Ubiquitous Detection of Artificial Sweeteners and Iodinated X-ray Contrast Media in Aquatic Environmental and Wastewater Treatment Plant Samples from Vietnam, The Philippines, and Myanmar.

Water samples from Vietnam, The Philippines, and Myanmar were analyzed for artificial sweeteners (ASs) and iodinated X-ray contrast media (ICMs). High concentrations (low micrograms per liter) of ASs, including aspartame, saccharin, and sucralose, were found in wastewater treatment plant (WWTP) influents from Vietnam. Three ICMs, iohexol, iopamidol, and iopromide were detected in Vietnamese WWTP influents and effluents, suggesting that these ICMs are frequently used in Vietnam. ASs and ICMs were found in river water from downtown Hanoi at concentrations comparable to or lower than the concentrations in WWTP influents. The ASs and ICMs concentrations in WWTP influents and adjacent surface water significantly correlated (r (2) = 0.99, p < 0.001), suggesting that household wastewater is discharged directly into rivers in Vietnam. Acesulfame was frequently detected in northern Vietnamese groundwater, but the concentrations varied spatially by one order of magnitude even though the sampling points were very close together. This implies that poorly performing domestic septic tanks sporadically leak household wastewater into groundwater. High acesulfame, cyclamate, saccharin, and sucralose concentrations were found in surface water from Manila, The Philippines. The sucralose concentrations were one order of magnitude higher in the Manila samples than in the Vietnamese samples, indicating that more sucralose is used in The Philippines than in Vietnam. Acesulfame and cyclamate were found in surface water from Pathein (rural) and Yangon (urban) in Myanmar, but no ICMs were found in the samples. The ASs concentrations were two-three orders of magnitude lower in the samples from Myanmar than in the samples from Vietnam and The Philippines, suggesting that different amounts of ASs are used in these countries. We believe this is the first report of persistent ASs and ICMs having ubiquitous distributions in economically emerging South Asian countries.

A meta-analysis of randomized controlled studies on the hepatoxicity induced by polybrominated diphenyl ethers (PBDEs) in rats and mice.

Several toxicological studies were conducted to evaluate the hepatoxicity of PBDEs using different animal models, congeners, duration of exposure, and other parameters. These variations in different animal models and conditions might have an impact on extrapolating experimental results to humans. Hence, by the meta-analysis, we aimed to clarify and elucidate the species differences in hepatoxicity induced by PBDE exposure in rats and mice across different conditions and moderators. Fourteen in vivo studies that utilized rats and mice models were identified, and data such as author names, year of publication, type of PBDE congeners, rodent species, life stage of exposure, dosage, duration, and hepatoxicity indicators were extracted. The pooled standard mean difference (SMD) with a 95% confidence interval (95% CI) was used to evaluate the association between hepatoxicity and PBDE exposure across multiple approaches of measurement. Subgroup analysis, meta-regression, and interaction analysis were utilized to elucidate the species-related differences among the results of the involved studies. The pooled SMD of hepatoxicity of PBDE exposure in the involved in vivo studies was 1.82 (p = 0.016), indicating exposure to PBDE congeners and mixtures is associated with a significant increase in liver toxicity in rodents. Moreover, findings showed that rats were more sensitive to PBDEs than mice with the BDE-209 had the highest SMD value. Among the life stages of exposure, embryonic stage was found to be the most sensitive to hepatoxicity induced by PBDE congeners. Positive relationships were found between the incidence of hepatoxicity with dosage and duration of exposure to PBDE. Interaction analyses showed significant interactions between rodent species (rats or mice), dosage, length of exposure, and hepatotoxicity endpoints. Rats demonstrated an increased susceptibility to variations in organ weight, histopathological changes, mitochondrial dysfunction, and oxidative stress markers. Conversely, mice showed pronounced lipid accumulation and modifications in liver enzyme expression levels. However, significant differences were not found in terms of endoplasmic reticular stress as a mechanistic endpoint for hepatotoxicity. In conclusion, this meta-analysis showed that there might be some species-related differences in hepatoxicity induced by PBDE exposure in rats and mice depending on the parameters used. This study highlights the importance of cross-species extrapolation of results from animal models to accurately assess the potential risks to human health from exposure to PBDEs.

Microplastics in dumping site soils from six Asian countries as a source of plastic additives.

The ubiquitous distribution of microplastics (MP) is a serious environmental issue in Asian countries. In this study, 54 open-dumping site soils collected from Cambodia, India, Indonesia, Laos, the Philippines, and Vietnam were analyzed for MP. Soil samples were also divided into light (floating) and heavy (sedimentation) fractions by density separation and analyzed for plastic additives. The highest abundance of MP was found in a soil from Cambodia at 218,182 pieces/kg. The median of MP in soils ranged from 1411 pieces/kg in India to 24,000 pieces/kg in the Philippines, suggesting that dumping sites are a major source of MP into the environment. Polyethylene, polypropylene, and polyethylene terephthalate were dominant polymers in soil samples analyzed. This indicates that daily-used plastic products are main sources of MP in dumping site soils in Asian countries. The high concentrations and burdens of phthalates and an antioxidant were detected in floating fraction accounting for 40 to 60% of the total additives in soils. Previous studies on soil pollution have assumed that the organic hydrophobic chemicals analyzed are adsorbed on the surface of soil particles. However, this result indicates that approximately half of the additives in dumping site soils were derived from MP, not soil particle. Monitoring study on soil pollution should be considered the occurrence of MP in the matrices.

Sources of sedimentary PAHs in tropical Asian waters: differentiation between pyrogenic and petrogenic sources by alkyl homolog abundance.

We collected surface sediment samples from 174 locations in India, Indonesia, Malaysia, Thailand, Vietnam, Cambodia, Laos, and the Philippines and analyzed them for polycyclic aromatic hydrocarbons (PAHs) and hopanes. PAHs were widely distributed in the sediments, with comparatively higher concentrations in urban areas (Sigma PAHs: approximately 1000 to approximately 100,000 ng/g-dry) than in rural areas ( approximately 10 to approximately 100g-dry), indicating large sources of PAHs in urban areas. To distinguish petrogenic and pyrogenic sources of PAHs, we calculated the ratios of alkyl PAHs to parent PAHs: methylphenanthrenes to phenanthrene (MP/P), methylpyrenes+methylfluoranthenes to pyrene+fluoranthene (MPy/Py), and methylchrysenes+methylbenz[a]anthracenes to chrysene+benz[a]anthracene (MC/C). Analysis of source materials (crude oil, automobile exhaust, and coal and wood combustion products) gave thresholds of MP/P=0.4, MPy/Py=0.5, and MC/C=1.0 for exclusive combustion origin. All the combustion product samples had the ratios of alkyl PAHs to parent PAHs below these threshold values. Contributions of petrogenic and pyrogenic sources to the sedimentary PAHs were uneven among the homologs: the phenanthrene series had a greater petrogenic contribution, whereas the chrysene series had a greater pyrogenic contribution. All the Indian sediments showed a strong pyrogenic signature with MP/P approximately 0.5, MPy/Py approximately 0.1, and MC/C approximately 0.2, together with depletion of hopanes indicating intensive inputs of combustion products of coal and/or wood, probably due to the heavy dependence on these fuels as sources of energy. In contrast, sedimentary PAHs from all other tropical Asian cities were abundant in alkylated PAHs with MP/P approximately 1-4, MPy/Py approximately 0.3-1, and MC/C approximately 0.2-1.0, suggesting a ubiquitous input of petrogenic PAHs. Petrogenic contributions to PAH homologs varied among the countries: largest in Malaysia whereas inferior in Laos. The higher abundance of alkylated PAHs together with constant hopane profiles suggests widespread inputs of automobile-derived petrogenic PAHs to Asian waters.

Occurrence of benzotriazole ultraviolet stabilizers (BUVSs) in human breast milk from three Asian countries.

The environmental contamination by benzotriazole ultraviolet stabilizers (BUVSs) has received consider attention due to their long-term and widespread usage in various consumer and industrial products in accordance with solar UV radiation increase. The present study shows the baseline data of BUVSs in human breast milk from several areas in Japan, the Philippines, and Vietnam. Total concentrations of the 8 BUVSs in breast milk ranged from

Distribution and transportability of hexabromocyclododecane (HBCD) in the Asia-Pacific region using skipjack tuna as a bioindicator.

The geographical distribution of hexabromocyclododecane (HBCD) was investigated through analysis of muscle tissue of skipjack tuna (Katsuwonus pelamis) collected from offshore waters of Asia-Pacific region (Japan, Taiwan, Philippines, Indonesia, Seychelles, Brazil, Japan Sea, East China Sea, South China Sea, Indian Ocean and North Pacific Ocean). HBCD was detected in almost all samples analyzed (<0.1 to 45 ng/g lipid weight basis), indicating widespread presence of this compound in the marine environment. Elevated concentrations of HBCD were found in skipjack tuna from areas around Japan, which have the larger modern industrial/urban societies, and implicated these areas as primary regional sources. All three individual HBCD isomers (alpha-, gamma- and beta-HBCD) were detected in almost all samples; the percentage contribution of the alpha-isomer to total HBCD increased with increasing latitude. The estimated empirical 1/2 distance for alpha-HBCD was 8500 km, which is one of the highest atmospheric transportability among various halogenated persistent organic pollutants (POPs).

Geographical distribution of polybrominated diphenyl ethers (PBDEs) and organochlorines in small cetaceans from Asian waters.

Polybrominated diphenyl ethers (PBDEs) are one of the flame retardants widely used in plastics, textiles, electronic appliances, and electrical household appliances. In this study, PBDEs and organochlorine compounds (OCs) were determined in the archived samples from the Environmental Specimen Bank for Global Monitoring (es-BANK) at Ehime University. The blubber of cetaceans found stranded along the coasts of Japan, Hong Kong, the Philippines and India during the period from 1990 to 2001 were employed for chemical analysis to understand the present status of contamination and the specific accumulation of PBDEs. PBDEs were detected in all the cetacean samples analyzed, and concentrations were one or two orders of magnitude lower than for PCBs and DDTs. Concentrations of PBDEs ranged from a low value of 6.0 ng/g lipid wt. in spinner dolphin (Stenella longirostris) from India to a high value of 6000 ng/g lipid wt. in Indo-Pacific humpback dolphin (Sousa chinensis) from Hong Kong. No difference in PBDE levels between coastal and offshore species from Japan was observed, implying the existence of pollution sources in this region other than Japan. Highest concentrations of PBDEs were found in animals from Hong Kong, followed by Japan, and much lower levels from the Philippines and India, suggesting that developing nations may also have pollution sources of PBDEs. Geographical distribution of PBDEs in Asian waters was different from PCBs but similar to DDTs.

Global pollution monitoring of polychlorinated dibenzo-p-dioxins (PCDDs), furans (PCDFs) and coplanar polychlorinated biphenyls (coplanar PCBs) using skipjack tuna as bioindicator.

In order to elucidate the global distribution of dioxins and related compounds, such as PCDDs, PCDFs and coplanar PCBs, levels of these compounds were determined in the muscle of skipjack tuna (Katsuwonus pelamis) collected from the offshore waters and open seas near Japan, Taiwan, Philippines, Indonesia, Seychelles and Brazil, and the Japan Sea, the East China Sea, the South China Sea, the Indian Ocean and the North Pacific Ocean. PCDDs, PCDFs and coplanar PCBs were detected in almost all the specimens collected from all the locations surveyed, indicating widespread contamination by these compounds in the marine environment. Higher concentrations of dioxins and coplanar PCBs were detected in the samples from temperate Asian regions, plausibly due to larger usage and anthropogenic generation in highly industrialized countries around the East China Sea and the South China Sea, such as Japan, Korea, Taiwan, Hong Kong and coastal China.

Distribution of linear alkylbenzenes (LABs) in riverine and coastal environments in South and Southeast Asia.

This paper reports the result of sewage pollution monitoring conducted in South and Southeast Asia during 1998-2003 using linear alkylbenzenes (LABs) as molecular tracers of sewage contamination. Eighty-nine water samples collected from Malaysia, Vietnam, and Japan (Tokyo), and 161 surface sediment samples collected from Tokyo, Thailand, Malaysia, Philippines, Vietnam, Cambodia, Indonesia, and India were analyzed for alkylbenzenes. The concentration range of SigmaLABs in river water particles in Southeast Asia (<0.005-0.913 microg/L) was comparable to or higher than those found in Tokyo (<0.005-0.638 microg/L). I/E ratios (a ratio of internal to external isomers of LABs) in tropical Asian waters were close to the value of LABs in raw sewage ( approximately 1) and much lower than those in secondary effluents (3-5). This suggests that untreated or inadequately treated sewage is discharged into the water. SigmaLABs concentrations in sediments from South and Southeast Asia ranged from <0.002-42.6 microg/g-dry with the highest concentration occurring at several populous cities. Low I/E ratios of the sediments with high SigmaLABs concentrations suggest a heavy load of untreated sewage. Clearly in view of the current data and evidence of the implications of sewage pollution, this paper highlights the necessity of the continuation of water treatment system improvement in tropical Asia.

Accumulation features of persistent organochlorines in resident and migratory birds from Asia.

Concentrations of organochlorine contaminants including polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane and its metabolites (DDTs), hexachlorocyclohexane isomers (HCHs), chlordane compounds (CHLs), hexachlorobenzene (HCB) were determined in the resident and migratory birds, which were collected from India, Japan, Philippines, Russia (Lake Baikal) and Vietnam. Accumulation patterns of organochlorine concentrations in resident birds suggested that the predominant contaminants of each country were as follows: Japan--PCBs Philippines--PCBs and CHLs, India--HCHs and DDTs, Vietnam--DDTs, and Lake Baikal--PCBs and DDTs. The migratory birds from Philippines and Vietnam retained mostly the highest concentrations of DDTs among the organochlorines analyzed, indicating the presence of stopover and breeding grounds of those birds in China and Russia. On the other hand, migratory birds from India and Lake Baikal showed different patterns of organochlorine residues, reflecting that each species has inherent migratory routes and thus has exposure to different contaminants. Species which have breeding grounds around the Red Sea and Persian Gulf showed high levels of PCBs, indicating the presence of areas heavily polluted by PCBs in the Middle East.

Asia-Pacific mussel watch: monitoring of butyltin contamination in coastal waters of Asian developing countries.

Butyltin compounds (BTs) including mono-, di-, and tributyltin and total tin (sigmaSn), were determined in green mussels (Perna viridis) from various Asian developing countries, such as Cambodia, China (Hong Kong and southern China), Malaysia, India, Indonesia, the Philippines, and Vietnam, to elucidate the contamination status, distribution, and possible sources and to assess the risks on aquatic organisms and humans. Butyltin compounds were detected in green mussels collected from all the sampling location investigated, suggesting widespread contamination of BTs along the coastal waters of Asian developing countries. Among butyltin derivatives, tributyltin (TBT) was the predominant compound, indicating its ongoing usage and recent exposures in Asian coastal waters. Higher concentrations of BTs were found in mussels collected at locations with intensive maritime activities, implying that the usage of TBT as a biocide in antifouling paints was a major source of BTs. In addition, relatively high concentrations of BTs were observed in mussels from aquaculture areas in Hong Kong and Malaysia, as it has been reported in Thailand. With the recent improvement in economic status in Asia, it is probable that an increase in TBT usage will occur in aquaculture. Although contamination levels were generally low in mussel samples from most of the Asian developing countries, some of those from polluted areas in Hong Kong, India, Malaysia, the Philippines, and Thailand revealed levels comparable to those in developed nations. Furthermore, the concentrations of TBT in some mussels from polluted areas exceeded the threshold for toxic effects on organisms and estimated tolerable average residue levels as seafoods for human consumption. A significant correlation was observed between the concentrations of sigmaBTs and sigmaSn in mussels, and sigmaBTs were made up mostly 100% of sigmaSn in mussels taken from locations having intensive maritime/human activities. This suggests that anthropogenic BTs represent the major source of tin accumulation in mussels. To our knowledge, this is a first comprehensive report on butyltin pollution monitoring in developing countries in the Asia-Pacific region.

Asia-Pacific mussel watch: monitoring contamination of persistent organochlorine compounds in coastal waters of Asian countries.

Contamination of persistent organochlorines (OCs) such as PCBs (polychlorinated biphenyls), DDT and its metabolites (DDTs), HCH (hexachlorocyclohexane) isomers (HCHs), chlordane compounds (CHLs), and HCB (hexachlorobenzene) were examined in mussels collected from coastal waters of Asian countries such as Cambodia, China, Hong Kong, India, Indonesia, Japan, Korea, Malaysia, Philippines, Far East Russia, Singapore, and Vietnam in 1994, 1997, 1998, 1999, and 2001 to elucidate the contamination status, distribution and possible pollution sources and to assess the risks on aquatic organisms and human. OCs were detected in all mussels collected from all the sampling sites investigated. Considerable residue levels of p,p(')-DDT and alpha-HCH were found in mussels and the concentrations of DDTs and HCHs found in mussels from Asian developing countries were higher than those in developed nations suggesting present usage of DDTs and HCHs along the coastal waters of Asian developing countries. On the other hand, lower concentrations of PCBs detected in mussels from Asian developing countries than those in developed countries indicate that PCBs contamination in mussels is strongly related to industrial and activities. To our knowledge, this is a first comprehensive report on monitoring OCs pollution in the Asia-Pacific region.

Organophosphorus flame retardants (PFRs) in human breast milk from several Asian countries.

In this study, the concentrations of 10 organophosphorus flame retardants (PFRs) were determined in 89 human breast milk samples collected from Japan, the Philippines and Vietnam. Among the targeted PFRs, tris(2-chloroexyl) phosphate (TCEP) and triphenyl phosphate (TPHP) were the predominant compounds and were detected in more than 60% of samples in all three countries. The concentrations of PFRs in human breast milk were significantly higher (p<0.05) in the Philippines (median 70 ng g(-1) lipid wt.) than those in Japan (median 22 ng g(-1) lipid wt.) and Vietnam (median 10 ng g(-1) lipid wt.). The present results suggest that the usage of products containing PFRs in the Philippines is higher than those of Japan and Vietnam. Comparing with a previous literature survey in Sweden, the levels of PFRs in human breast milk from the Philippines were 1.5-2 times higher, whereas levels in Japan and Vietnam were 4-20 times lower, suggesting that these differences might be due to their variation in the usage of flame-retarded products utilized in each country. When daily intake of PFRs to infants via human breast milk was estimated, some individuals accumulated tris(2-butoxyethyl) phosphate (TBOEP) and TCEP were close to reference dose (RfD). This is the first report to identify PFRs in human breast milk samples from Asian countries.

Accumulation of brominated flame retardants and polychlorinated biphenyls in human breast milk and scalp hair from the Philippines: levels, distribution and profiles.

Paired human breast milk and scalp hair samples (n=30) were obtained in 2008 from primipara and multipara mothers living in two locations in the Philippines viz., Payatas, a waste dumpsite, and Malate, a non-dumpsite. Samples were analyzed for three groups of organohalogenated compounds, such as polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecanes (HBCDs). PCBs were the predominantly identified compounds (median: 70 ng/g lipid wt.) in all the breast milk samples. In the human milk, CB-153 was the most dominant PCB congener (17-44% contribution to the sum PCB), closely followed by CB-138 (12-35%), CB-118 (4-12%), CB-180 (2-13%), CB-187 (3-13%), and CB-170 (1.5-10%). Levels of PBDEs (median: 3.0 ng/g lipid wt.) in human milk samples from the Philippines were similar to other Asian or European countries. BDE-47, -99, -100 and -153 were the major PBDE congeners. For HBCDs, the α-isomer was predominant followed by the γ-HBCD isomer in the both locations. PBDE levels in human milk were significantly higher in the dumpsite (3.9 ng/g lipid wt.) than in the non-dump site (2.2 ng/g lipid wt.). PBDE concentrations (including BDE-209) were significantly higher (median: 70 ng/g hair) than those of PCBs (median: 30 ng/g hair) and HBCDs (median: 1.0 ng/g hair) in all the scalp hair samples. To our knowledge, this is the first report on HBCDs in human scalp hair. PBDE congeners in scalp hair were dominated by BDE-209 and BDE-47. On a congener basis, the levels of PBDEs found in scalp hair were higher than those in Spain (children and adults) and China (general people). PCB levels found in scalp hair were higher than those in Greece, Romania and Belgium, but lower than those in China. In this study, there were no significant differences in the concentration of PCBs and HBCDs in human milk; and PCBs, HBCDs and PBDEs in human scalp hair from the two different locations. No significant correlations were observed between PCBs, PBDEs and HBCDs levels and age of mothers in this study, which may be due to the small number of samples. Furthermore, there was no correlation between milk and hair levels for more persistent compounds (PCB-153, PCB-138, or BDE-47), and thus it is worthy to follow-up in future studies along with more number of samples. This is the first report to provide measurement data for PCBs, PBDEs and HBCDs in paired milk and hair of populations in the Philippines.

Organophosphorus flame retardants in house dust from the Philippines: occurrence and assessment of human exposure.

The use of organophosphorus flame retardants (PFRs) as flame retardants and plasticizers has increased due to the ban on common polybrominated diphenyl ether mixtures. However, only limited information on PFR contamination is available so far from Southeast Asia. In the present study, residual levels of PFRs in house dust and exposure through dust ingestion were investigated in the Philippines. House dust samples (n = 37) were collected from Malate (residential area) and Payatas (municipal dumping area) in the Philippines and analyzed using ultra-high-performance liquid chromatography coupled with tandem mass spectrometry. Among the targeted seven PFRs, triphenyl phosphate (TPP) was the predominant compound. Median levels of ΣPFRs in Malate (530 ng/g) were two times higher (p < 0.05) than in Payatas (240 ng/g). The estimated daily intake of PFRs in the Philippines (of areas studied) via house dust ingestion was below the guideline values. House dust may be an important contributor in the overall exposure of humans to TPP even when considering dietary sources. To our knowledge, this is a first report on PFR contamination in house dust from developing country. PFRs were ubiquitously detected in the home environments in the Philippines. Although estimated exposure levels through dust ingestion were below the guideline, it was suggested that toddlers are at higher risk. Therefore, further investigations to understand the behavior of PFRs in house and other microenvironments and overall exposure pathways for the country's populace to PFRs are necessary.

Contamination of benzotriazole ultraviolet stabilizers in house dust from the Philippines: implications on human exposure.

Seven compounds of benzotriazole ultraviolet stabilizers (BUVSs) were determined in house dust samples collected from a residential area (Malate: n = 17) and municipal dumping area (Payatas: n = 20) in the Philippines. Total concentrations of the 7 BUVSs in house dust ranged from ND (not detected) to 1020 ng/g in Malate and ND to 277 ng/g in Payatas. Among the target compounds, the most abundant BUVS was UV-234, with a median value of 84 ng/g (ND-813 ng/g) in Malate and 41 ng/g (ND-212 ng/g) in Payatas, respectively. Significantly higher concentrations of UV-326 (p<0.01) and UV-327 (p<0.05) were found in house dust samples from Malate than those from Payatas, suggesting that the household products are the major sources of contamination in the indoor microenvironment. The estimated daily intakes (EDIs) of BUVSs through house dust ingestion in the Philippines were two to four orders of magnitude lower than the guideline values. However, the EDI of 5 BUVSs for toddlers in this study was 5 times higher than those for adults, suggesting that toddlers are at higher risk. House dust may be an important exposure route of UV-234 (88%) and UV-326 (69%) in worst-case scenarios, which using high dust ingestion and worst-case exposure (P95). To our knowledge, this is the first comprehensive study on BUVSs in house dust samples from Asian developing countries and reporting the occurrence of UV-234 and UV-320 in dust samples.

Asia-Pacific mussel watch for emerging pollutants: Distribution of synthetic musks and benzotriazole UV stabilizers in Asian and US coastal waters.

We analyzed 68 green and blue mussels collected from Cambodia, China, Hong Kong, India, Indonesia, Japan, Korea, Malaysia, Philippines, Vietnam and the USA during 2003 and 2007, to elucidate the occurrence and widespread distributions of emerging pollutants, synthetic musks and benzotriazole UV stabilizers (BUVSs) in Asia-Pacific coastal waters. Synthetic musks and BUVSs were detected in mussels from all countries, suggesting their ubiquitous contamination and widespread distribution. High concentrations of musks and BUVSs were detected in mussels from Japan and Korea, where the levels were comparable or greater than those of PCBs, DDTs and PBDEs. Significant correlations were found between the concentrations of HHCB and AHTN, and also between the concentrations of UV-327 and UV-328, which suggest similar sources and compositions of these compounds in commercial and industrial products. To our knowledge, this is the first study of large-scale monitoring of synthetic musks and BUVSs in Asia-Pacific coastal waters.

Organohalogen compounds in human breast milk from mothers living in Payatas and Malate, the Philippines: levels, accumulation kinetics and infant health risk.

Human breast milk samples (n=33) from primipara and multipara mothers from Payatas a waste dump site, and Malate a reference site in the Phillipines were collected in 2004 and analyzed for eight organohalogen compounds, viz., PCBs, DDTs, CHLs, HCHs, HCB, TCPMe, PBDEs and HBCDs. DDTs and PCBs were predominant in all the samples. Overall mean concentrations of PBDEs found in our study were higher (7.5 ng/g lipid wt.) than those reported for Japan and many other Asian countries. Primipara mothers had significantly higher levels of DDTs, CHLs and HCHs than multipara mothers, but not PBDEs and HBCDs. A few individuals accumulated CHLs close to or even higher than the tolerable daily intake guidelines proposed by Health Canada.

Transport and release of chemicals from plastics to the environment and to wildlife.

Plastics debris in the marine environment, including resin pellets, fragments and microscopic plastic fragments, contain organic contaminants, including polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons, petroleum hydrocarbons, organochlorine pesticides (2,2'-bis(p-chlorophenyl)-1,1,1-trichloroethane, hexachlorinated hexanes), polybrominated diphenylethers, alkylphenols and bisphenol A, at concentrations from sub ng g(-1) to microg g(-1). Some of these compounds are added during plastics manufacture, while others adsorb from the surrounding seawater. Concentrations of hydrophobic contaminants adsorbed on plastics showed distinct spatial variations reflecting global pollution patterns. Model calculations and experimental observations consistently show that polyethylene accumulates more organic contaminants than other plastics such as polypropylene and polyvinyl chloride. Both a mathematical model using equilibrium partitioning and experimental data have demonstrated the transfer of contaminants from plastic to organisms. A feeding experiment indicated that PCBs could transfer from contaminated plastics to streaked shearwater chicks. Plasticizers, other plastics additives and constitutional monomers also present potential threats in terrestrial environments because they can leach from waste disposal sites into groundwater and/or surface waters. Leaching and degradation of plasticizers and polymers are complex phenomena dependent on environmental conditions in the landfill and the chemical properties of each additive. Bisphenol A concentrations in leachates from municipal waste disposal sites in tropical Asia ranged from sub microg l(-1) to mg l(-1) and were correlated with the level of economic development.

Asian Mussel Watch Program: contamination status of polybrominated diphenyl ethers and organochlorines in coastal waters of Asian countries.

Mussel samples were used in this study to measure the levels of polybrominated diphenyl ethers (PBDEs) and organochlorines (OCs) in the coastal waters of Asian countries like Cambodia, China, Hong Kong, India, Indonesia, Japan, Korea, Malaysia, the Philippines, and Vietnam. PBDEs were detected in all the samples analyzed, and the concentrations ranged from 0.66 to 440 ng/g lipid wt. Apparently higher concentrations of PBDEs were found in mussels from the coastal waters of Korea, Hong Kong, China, and the Philippines, which suggests that significant sources of these chemicals exist in and around this region. With regard to the composition of PBDE congeners, BDE-47, BDE-99, and BDE-100 were the dominant congeners in most of the samples. Among the OCs analyzed, concentrations of DDTs were the highest followed by PCBs > CHLs > HCHs > HCB. Total concentrations of DDTs, PCBs, CHLs, and HCHs in mussel samples ranged from 21 to 58 000, 3.8 to 2000, 0.93 to 900, and 0.90 to 230 ng/g lipid wt., respectively. High levels of DDTs were found in mussels from Hong Kong, Vietnam, and China; PCBs were found in Japan, Hong Kong, and industrialized/urbanized locations in Korea, Indonesia, the Philippines, and India; CHLs were found in Japan and Hong Kong; HCHs were found in India and China. These countries seem to play a role as probable emission sources of corresponding contaminants in Asia and, in turn, may influence their global distribution.