Assessment of chlorinated pesticide exposure to white-rumped vulture Gyps bengalensis in India.

Populations of the critically endangered white-rumped vulture (WRV) Gyps bengalensis have declined drastically due to the use of diclofenac for veterinary purposes in Indian subcontinent. Thirty-two dead WRVs collected from three states, namely Gujarat, Assam and Tamil Nadu in India between 2011 and 2014 were investigated to understand the role of diclofenac in the death, and the results were published. Furthermore, since organochlorine pesticides have been linked to long-term impact on populations in many species of birds across the globe, available tissues of 21 WRVs were tested also for six organochlorine pesticides (DDT, HCH, endosulfan, heptachlor, dieldrin and dicofol) and chlorpyrifos. All vultures were found to have had one or more detectable levels of pesticides in their tissues except one. Similarly, all the pesticides included in the study were detected in at least one of the vultures analysed. DDT (95.2%) was the most frequently detected pesticide followed by HCH (90.5%), and DDT (73.6%) contributed the most to the total pesticide load. Total pesticide load ranged between below detection limit (BDL) and 8753.4 ng/g. High levels of total pesticide load recorded in gut contents showed recent exposure to these legacy pesticides even long after their ban. However, it is perceived that studied pesticides' exposure to birds and their presence in the environment is in decreasing trend in India. Although, varying levels of pesticides were detected, all of which were below the levels reported to be toxic, and also reported earlier in the same species in India. Recorded levels may not create a problem to vultures unlike diclofenac; nevertheless, as continued exposure to the pesticides studied may lead to sub lethal effects in birds, it is prudent to monitor these pesticides along with new generation pesticides and NSAIDs in the critically endangered white-rumped vulture in India, towards its conservation.

Placental concentrations of xenoestrogenic organochlorine pesticides and polychlorinated biphenyls and assessment of their xenoestrogenicity in the PA-MAMI mother-child cohort.

BACKGROUND: Organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCB), they have contributed to the exposure of women to persistent organic pollutants (POPs). These compounds can cross the placental barrier and interfere with the hormonal system of newborns. AIM: To determine concentrations of OCPs and PCBs and their xenoestrogenic activity in placentas of women from the PA-MAMI cohort of Panama. METHODS: Thirty-nine placenta samples from women in the Azuero peninsula (Panama) were analyzed. Five OCPs [p-p'-dichlorodiphenyldichloroethylene (p-p'-DDE), beta-hexachlorohexane (ß-HCH), γ-hexachlorohexane (lindane), hexachlorobenzene (HCB) and mirex] and three PCB congeners (PCB-138, PCB-153 and PCB-180) were quantified in placenta extracts. The xenoestrogenic activity of extracts was assessed with the E-Screen bioassay to estimate the total effective xenoestrogen burden (TEXB). RESULTS: All placental samples were positive for at least three POP residues and >70% for at least six. The frequencies of quantified OCPs ranged from 100% for p,p'-DDE and HCB to 30.8% for ß-HCH. The highest median concentration was for lindane (380.0 pg/g placenta), followed by p,p'-DDE (280.0 pg/g placenta), and HCB (90.0 pg/g placenta). Exposure to p,p'-DDE was associated with greater meat consumption, suggesting that animal fat is a major source of exposure to DDT metabolites. The frequency of detected PCBs ranged between 70 and 90%; the highest median concentration was for PCB 138 (17.0 pg/g placenta), followed by PCB 153 (16.0 pg/g placenta). All placentas were positive in the estrogenicity bioassay with a median TEXB-α of 0.91 pM Eeq/g of placenta. Exposure to lindane was positively associated with the xenoestrogenicity of TEXB- α, whereas this association was negative in the case of exposure to PCB 153. CONCLUSIONS: To our best knowledge, this study contributes the first evidence on the presence of POPs and xenoestrogenic burden in placentas from Latin-American women. Given concerns about the consequences of prenatal exposure to these compounds on children's health, preventive measures are highly recommended to eliminate or minimize the risk of OCP exposure during pregnancy.

Status, sources, and human health risk assessment of DDT pesticide residues in river sediments in a highly developed agricultural region in the upper Yangtze River in China.

The concentrations of DDT and its metabolites in 19 sediment samples from a highly developed agricultural region in the upper reaches of the Yangtze River were measured. Non-carcinogenic hazard quotient for different age groups was evaluated using reference doses provided by the USEPA, and the excess lifetime cancer risk due to eating fish was assessed based on the local eating habits. The results showed that this region had a high level of residual DDT (12.84 ± 8.97 ng/g), which mainly came from the historically used technical DDT in agriculture. The non-carcinogenic risk was just acceptable in the region, but 11 of the 19 sites showed an unacceptable carcinogenic risk. Although DDT has been banned for decades, there were still notable health risks, especially for children. Special attention should be given to the potential health risks in historically developed agricultural regions.

Organochlorines in the riverine ecosystem of Punjab province, Pakistan: contamination status, seasonal variation, source apportionment, and ecological risk assessment.

The aim of the present study was to determine the occurrence, spatio-temporal variations, source apportioning, and ecological risk assessment of selected PCBs and OCPs in surface water and sediments collected riverine environment of Punjab province, Pakistan. The concentration of ΣOCPs (water: 64-455 ng/L; sediments: 117-616 ng/g) and ΣPCBs (water: 2-132 ng/L; sediments: 3.27-200 ng/g) was found comparatively higher than the levels reported from other parts of the world. The higher concentrations of DDTs and HCHs were detected in both studied matrices, whereas among PCBs, CB-28, 49 and CB-37, 82 were dominant in water and sediments, respectively. The isomeric ratios including α-HCH/γ-HCH, (DDE + DDD) / DDTs, and α /ß-endosulfan reflected the recent use of lindane, technical DDT, and endosulfan in the study area. The WHO-TEQ values of DL-PCBs ranged from 3.6 × 10-6 to 0.115 ng/L and 8.7 × 10-6 to 0.157 ng/g in surface water and sediments in both seasons, respectively. The spatial variation analysis revealed that the sites in the industrial and agricultural zones were highly contaminated. The OCPs and PCBs fluxes to downstream areas were estimated to be 12.4 tons/year and 1.9 tons/year, respectively. The significant ecological risks were estimated to be posed by OCPs and PCBs, as their levels in 67% and 62% of surface water and sediment samples were exceeding the threshold limits, highlighting effects to ecological integrities.

Outdoor Atmospheric Micro-/Nanomineral-Mediated Organochlorine Pesticides in Sichuan Basin, China: Adsorption, Occurrence, and Risk Assessment.

Atmospheric micro-/nanominerals play an important role in the adsorption, enrichment, and migration of organochlorine pesticides (OCPs). In the present study, the correlations between OCPs and minerals in outdoor atmospheric dustfall were investigated, and the correlations were used to speculate the source of p,p'-(dicofol+dichlorobenzophenone [DBP]), which is the sum of p,p'-dicofol and p,p'-DBP. Atmospheric dustfall samples were collected from 53 sites in the Chengdu-Deyang-Mianyang economic region in the Sichuan basin. In this region, 24 OCPs were analyzed by gas chromatography-tandem mass spectrometry. The average concentration of 24 OCPs was 51.2 ± 27.4 ng/g. The results showed that the concentration of Σ24 OCPs in urban areas was higher than that in suburban areas (p < 0.05). Minerals in atmospheric dustfall were semiquantitatively analyzed by X-ray diffraction. The primary minerals were quartz, calcite, and gypsum. A Spearman correlation analysis of OCPs and minerals showed that low-volatility OCPs could be adsorbed by minerals in atmospheric dustfall. A density functional theory simulation verified that p,p'-(dicofol+DBP) in atmospheric dustfall was primarily derived from the p,p'-dicofol adsorbed by gypsum. Isomeric ratio results suggested that the samples had weathered lindane and chlordane profiles and confirmed that residents in the Sichuan basin used technical dichlorodiphenyltrichloroethane. Finally, the OCPs were evaluated to determine the potential risk of cancer in adults and children from OCP exposure. Exposure to OCPs via atmospheric dustfall was safe for adults. The cancer risk for children exposed to OCPs was slightly lower than the threshold value (10-6 ) under a high dust ingestion rate, which poses a concern. Environ Toxicol Chem 2023;42:594-604. © 2022 SETAC.

A new insight into the emission source of DDT in indoor environment from rural area of South China and comprehensive human health exposure assessment.

Human exposure to dichlorodiphenyltrichloroethanes (DDTs) and the subsequent risk to human health remain an important concern due to the "new" input of DDTs in the environment, especially since exposure to DDTs in indoor microenvironments is often ignored. In this study, we identified a new source of DDT emission in indoor environments and evaluated the health risk from the exposure to DDTs by investigating DDTs in indoor and outdoor dust, air, and coatings of household items in rural areas of Qingyuan, South China. The concentrations of DDTs in house dust and air were < MQL (method quantification limit)-3450 ng/g (median 42.4 ng/g) and 22.7-965 pg/m3 (median 49.5 pg/m3), respectively, which were significantly higher than the outdoor DDT values. Dichlorodiphenyldichloroethylene (DDE) was the main isomer in air samples, while DDT was the dominant isomer in indoor dust. Significant correlations between different DDT isomers were observed in indoor samples but not in outdoor samples. Furniture coating was identified as a source of DDTs in the indoor dust. The total daily exposure dose of DDTs (1.75 × 10-2 ng/kg bw/day for adults and 1.28 × 10-1 ng/kg bw/day for toddlers) through inhalation, dust ingestion, and dermal contact was found unlikely to pose a health risk. Our findings provide new insights into the emission sources and health risks caused by DDT indoors, highlighting the need to further investigate the toxicity mechanisms of parent DDT compound.

Distribution characteristics, sources, and risk assessment of organochlorine pesticides in the Fildes Peninsula and Adelaide Island.

This work analyzed the distribution characteristics, sources, and corresponding environmental risks of 10 organochlorine pollutants (OCPs) in soil samples from 13 stations on the Fildes Peninsula and Adelaide Island in Antarctica in 2020. Results showed that the total amount of OCP residues in the study area ranged from N.D. to 2.66 ng·g-1 with an average concentration of 0.90 ng·g-1. Six organochlorine pesticides were detected, and the residue level of DDTs was slightly lower than that of HCHs. The residues of HCHs were mainly γ-HCH and those of DDTs were mainly O, P'-DDT. Source analysis revealed that the residues mainly originated from atmospheric transport and human activities. Environmental risk analysis showed that in the study area, the residues of HCHs and DDTs were present at low levels, and their ecological risk was low.

Organochlorine pesticides in therapeutic teas and human health risk assessment.

This study evaluated commercially available therapeutic teas for their organochlorine pesticides (OCPs) residue levels to estimate the potential health risks associated with their prolonged consumption. Tea samples that were produced for therapeutic uses were obtained commercially. Organochlorine pesticide residues were extracted from the samples using the modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) method and analysed using Gas Chromatography with Electron Capture Detector (GC-ECD). Results showed that the tea samples contained a large number of OCPs residue at levels that were significantly higher than the maximum residue limits (MRLs) set by the European Union (p > 0.05). Aldrin was detected in all samples, methoxychlor, and p,p'-DDT were detected in ≥88% of the samples while γ-HCH, δ-HCH, endosulfan II, and endosulfan sulphate were detected in ≥69% of the samples. Health risk assessment indicated that the highest risk of cancer was associated with aldrin.

Occurrence and risk assessment of endocrine-disrupting compounds in fish muscle: The case study of the Douro River estuary (North East Atlantic Ocean).

This work was focused on evaluating the occurrence of endocrine-disrupting compounds (EDCs) in fish muscles, such as bisphenol analogues, personal care products, including some UV-filters and musk fragrances, and selected pesticides. A total of 238 muscle samples of three fish species (Platichthys flesus, Mugil cephalus, and Dicentrarchus labrax) of an important estuary ending in the North East Atlantic Ocean (Douro River estuary, Portugal), in different seasons of the year, was analysed. M. cephalus was the species with a greater occurrence of contaminants, mainly in fishes collected during the spring. Bisphenol A was the main bisphenol analogue detected with an average content of 23.1 µg/kg wet weight (w.w.). Among chemicals used in personal care products, galaxolide, tonalide, and 2-ethylhexyl salicylate, were the most often found, being present in 15.9% (2.2-538.4 µg/kg w. w.), 4.6% (1.1-57.8 µg/kg w. w.) and 3.4% (3.9-56.1 µg/kg w. w.) of the samples, respectively. About 14% of the samples contained residues of at least one pesticide, being alachlor, aldrin, p,p'-DDT, permethrin, and prochloraz the main chemicals observed, varying from 0.1 µg/kg w. w. (p,p'-DDT) to 37.8 µg/kg w. w. (prochloraz). The daily intake estimates of the most frequent EDCs found in the fish muscles suggested that there are no health concerns, based on the recommended weekly consumption of fish for adults.

Freely dissolved organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) along the Indus River Pakistan: spatial pattern and risk assessment.

Freely dissolved OCPs and PCBs were measured by using polyethylene passive samplers at 15 sites during 2014 throughout the stretch of the Indus River to investigate the spatial pattern and risk assess. Levels (pg/L) of dissolved ∑OCPs and ∑PCBs ranged from 34 to 1600 and from 3 to 230. Among the detected OCPs, dissolved DDTs (p,p'-DDE, followed by p,p'-DDT) predominated with levels of 0.48 to 220 pg/L. The order of occurrence for other studied OCPs was as follows: HCB, endosulfans, chlordanes, and HCHs. Spatially, dissolved (pg/L) ∑OCPs varied (p < 0.05) as the following: surface water of the alluvial riverine zone (ARZ) showed the highest levels (114) followed by the frozen mountain zone (FMZ) (52.9), low-lying zone (LLZ) (28.73), and wet mountain zone (WMZ) (14.43), respectively. However, our zone-wise PCB data did not exhibit significant differences (p > 0.05). Principal component analysis/multilinear regression results showed pesticide usage in the crop/orchard fields and health sector, electric and electronic materials, and widespread industrial activities as the main source of OCPs and PCBs along the Indus River. Our results showed that OCPs and PCBs contaminated water intake, playing an important role towards the considerable cancer/non-cancer risk (HI and CR values) along the Indus River Flood-Plain.

Occurrence, source, and ecological risk assessment of organochlorine pesticides and polychlorinated biphenyls in the water-sediment system of Hangzhou Bay and East China Sea.

The pollution characteristics, potential sources, and potential ecological risk of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) were investigated in the Hangzhou Bay (HZB) and East China Sea (ECS). Total OCPs concentration ranged from 2.62 to 102.07 ng/L and 4.41 to 75.79 µg/kg in the seawater and sediment samples, with PCBs concentration in the range of 0.40-51.75 ng/L and 0.80-45.54 µg/kg, respectively. The OCPs were positively correlated with nutrients, whereas PCBs presented a negative correlation. The newly imported dichlorodiphenyltrichloroethane (DDT) in HZB is mainly the mixing of technical DDT and dicofol sources. The PCB source composition is more likely related to the mixture of Kanechlor 300, 400, Aroclor 1016, 1242, and Aroclor 1248. Risk assessment results indicate that OCPs posed low risk in seawater. The potential risk of DDTs in the sediments is a cause of concern.

Distribution, sources, and ecological risk assessment of HCHs and DDTs in water from a typical coal mining subsidence area in Huainan, China.

Coal mining subsidence areas are a special and widespread ecosystem in China and many developing countries in the world. However, limited research has focused on HCHs and DDTs in coal mining subsidence areas. Investigating the concentration, distribution, and sources of HCHs and DDTs at the Yangzhuang coal mining subsidence area in Huainan, China, is the object of this study. Water samples from different depths were collected from this region to detect and analyze HCHs and DDTs using gas chromatography-mass spectrometry. The result showed that the concentrations of HCHs and DDTs increased with increasing water depth, and the average concentrations of HCHs and DDTs in the top (T-layer), middle (M-layer), and bottom (B-layer) layers were 152, 169, and 182 ng∙L-1, respectively. Spatial distribution of HCH and DDT concentrations in the study area revealed that the concentrations gradually decreased in the direction of water flow, and the highest concentration was observed at the entrance of the Nihe River. The T-layer was easily influenced by environmental and human activities, while the M-layer and B-layer were mainly influenced by sediment. Using principal component analysis and diagnostic ratios, we found that HCHs and DDTs in the study area mainly originated due to natural and human activities (such as pesticide use). Hexachlorocyclohexanes (HCHs) were mainly derived from lindane, and dichlorodiphenyltrichloroethanes (DDTs) mainly originated due to the recent agricultural use of dicofol; both of these are directly related to agricultural activities. Based on a comparison of reported concentrations of HCHs and DDTs in the rivers and lakes throughout China, we found that the overall ecological risk of HCHs and DDTs in the study area was elevated. The results are important for further understanding the transfer characteristics of HCHs and DDTs as well as the ecological health of the water in coal mining subsidence areas.

Legacy organochlorines in estuarine sediment in relation to socioeconomic pattern in multi-coastal watersheds.

Estuarine sediment quality is highly associated with anthropogenic activities in watersheds. This study attempts to couple socioeconomic patterns with estuarine sediment quality via legacy organochlorines in 14 Chinese coastal watersheds. Sedimentary concentrations of HCHs, DDTs, and PCBs showed a significant spatiality in estuary, up to 48.7 ± 15.1, 89.0 ± 46.4, and 54.5 ± 17.2 ng g-1, which were predominated by ß-HCH, p,p'-DTs, and tri- to penta-PCBs, respectively. Ecological risk of organochlorines was negligible except few moderate risks for DDTs and PCBs against the first class quality of the marine sediment quality guidelines of China. Sedimentary DDT and PCB concentrations were significantly delineated by an environmental Kuznets curve model as a function of non-agricultural GDP per capita in watersheds, while HCHs by an increasing linear model. Findings of this study provide a tool to quantify the contribution of anthropogenic development in watershed to environmental change in estuary across the world.

The concentration of persistent organic pollutants in water resources: A global systematic review, meta-analysis and probabilistic risk assessment.

The persistent organic pollutants (POPs) are environmentally stable and highly toxic chemicals that accumulate in living adipose tissue and have a very destructive effect on aquatic ecosystems. To analyze the evolution of the concentration and prevalence of POPs such as α-HCH, ß-HCH, γ-HCH, ∑-HCH, Heptachlor, Aldrin, p,p'-DDE, p,p'-DDT, ∑-DDT, and ∑-OCP in water resources, a search between January 01, 1970, to February 10, 2020, was followed using a systematic review and meta-analysis prevalence. Among the 2306 explored articles in the reconnaissance step, 311 articles with 5315 exemplars, 56 countries, and 4 types of water were included in the meta-analysis study. Among all studied POPs, the concentration of p,p'-DDT in water resources was the highest, especially in drinking water resources. The overall rank order based on the concentration and prevalence of POPs were surface water > drinking water > seawater > groundwater. To identify POPs-contaminated areas, the distance from the mean relative to their distribution was considered. The most to the least polluted areas included: South Africa, India, Turkey, Pakistan, Canada, Hong Kong, and China. The highest carcinogenic risk was observed for ß-HCH (Turkey and China), followed by α-HCH (Mexico). The highest non-carcinogenic risk was identified for Aldrin (all analyzed countries), followed by Dieldrin (Turkey) and γ-HCH (Mexico). The Monte Carlo analysis (under the assumption that γ-HCH has a normal distribution), the mean obtained was 8.22E-07 for children and 3.83E-07 for adults. This is in accordance with the standard risk assessment approach. In terms of percentiles, the Monte-Carlo approach indicates that 75% of child population is under the 1.07E-06 risk and 95% of adults under 7.35E-06.

Health risks of exposure to soil-borne dichlorodiphenyltrichloroethanes (DDTs): A preliminary probabilistic assessment and spatial visualization.

Residues of dichlorodiphenyltrichloroethane and its metabolites (DDTs) in soils continue to severely threaten and endanger human health. This present study comprehensively interprets the health risks associated with exposure to soil-borne DDTs and also identifies the spatial visualization of risks at a large regional scale in Fujian, China. There was significant spatial variability of human risk across the region, while levels of health risk displayed a significant positive correlation with population density (p < 0.05). High risk levels occurred mostly in the coastal areas in northeastern Fujian, with additional hotspots in inland areas. The highest total incremental lifetime cancer risks (ILCRs) occurred in Sanming, reaching up to 9.52 × 10-5, 3.27 × 10-5, and 1.76 × 10-4 for children, teens, and adults, respectively. Further, the highest hazard index (HI) value was observed in Fuzhou, reaching up to 6.09, 3.84, and 2.37, respectively. The 95% confidence interval of data regarding ILCRs exceeded the recognized safe threshold, whereas the HI has been deemed accepted. Adults were identified as the most susceptible population in terms of cancer risks, with o,p'-DDT being the primary contributor of ILCRs. Moreover, children were showed to be the most vulnerable in terms of non-cancer risks, with p,p'-DDD being the main contributor of HI. Food ingestion appeared to be the dominant exposure pathway, for both cancer and non-cancer risks. The concentration of DDTs (Csoil) and exposure duration (ED) also greatly influenced the risk, together contributing to over 99% of the ILCRs and HI.

Bioaccumulation and human health risk assessment of DDT and its metabolites (DDTs) in yellowfin tuna (Thunnus albacares) and their prey from the South China Sea.

DDTs were detected in yellowfin tuna (Thunnus albacares, 92.1-221.8 ng‧g-1 lipid weight) and their prey (54.9-93.5 ng‧g-1 lipid weight) from the South China Sea (SCS). DDT levels reported in this study were lower than those of the previous studies indicated the recent mitigation of DDT contamination in the SCS. Higher DDT levels were observed in fat abdominal muscle than lean dorsal muscle in adult yellowfin tuna. Meanwhile, DDT levels in adult yellowfin tuna were higher than the young ones. The composition profiles of DDT and its metabolites suggested DDTs in fish in the SCS were mainly derived from the historical use of technical DDTs. DDTs were biomagnified through food chains with the trophic magnification factor of 2.5. Risk assessment results indicated that dietary exposure to DDTs through lifetime fish consumption from the SCS would pose little cancer and noncarcinogenic risk to coastal residents.

Pesticide residues in breast milk and the associated risk assessment: A review focused on China.

This review aims to provide an overview of studies on pesticide residues in breast milk in China and the related health risk to mother and infants. Results showed that the investigations of breast milk covered 22 provincial administrative regions of China. Beijing and some densely populated and economically developed areas have most publications. The study frequency was followed the order of DDTs>HCHs>HCB > ∑Drins,∑Chlordane. While the residue levels were ranked as DDTs, HCHs > ∑Drins>HCB > ∑Chlordane. The highest residue levels of DDTs and HCHs in breast milk were found in 1980s (~10,000 ng/g lipid), then experienced a sharp decrease in 1990s (~1000-2000 ng/g lipid). In 2000s and 2010s, DDTs, and HCHs residue still showed a decreasing trend. Spatially, people located in urban area, coastal areas and southern China tend to have higher pesticide residues as compared to rural area, inland area and northern China, respectively. Other factors such as dietary habit, living environment, the maternal age, the parity, body mass index, lactation period, menstruation characteristics as well as hormonal drug intake and infertility treatment will also affect the pesticide residues in breast milk of Chinese people. According to the estimated daily ingestion (EDI) of breast milk, the average health risk for infants were generally exceeded the acceptable level before 2006, while after that, most EDI values were within the standard. Body burden of pesticides in mother can also be evaluated by using the residue data in breast milk, but no relevant guidelines were available. Other knowledge gap included 1) for some provinces with large consumption of pesticides or located in remote and plateau areas, there are few/no studies available; 2) current study on pesticide residues in breast milk in China were only focused on organochlorine pesticides, research on current used pesticides (such as pyrethroids, organophosphorus, carbamate) were necessary in the future.

Spatial Distribution and Ecological Risk Assessment of Residual Organochlorine Pesticides (OCPs) in South American Marine Environments.

PURPOSE OF REVIEW: Organochlorine pesticides (OCPs) have been intensely used and produced in South America. Although they were banned before the year 2000 (excepting endosulfan, which has been recently banned in several countries), OCPs remain detectable in marine environments of this continent, sometimes at risky levels for biota. This manuscript summarizes studies on OCP levels in the air, water, sediment, bivalves, fish, and marine mammals of the South American coasts and open waters over the last 20 years, tackling their spatial distribution and analyzing their associated ecotoxicological risk. RECENT FINDINGS: To the best of our knowledge, this is the first study integrating all available information on current levels of OCPs in South American marine environments. The 63 researches reviewed studied punctual sites or environmental compartments. The OCP levels were higher in semi-enclosed environments such as bays and estuaries, close to large cities. In terms of individual OCPs, dichlorodiphenyltrichloroethane (DDT) and its degradation products were more abundant than other OCPs in all the environmental compartments, excepting air, for which the most abundant OCP was endosulfan. Depending on the location and the environmental matrix, hexachlorocyclohexanes (HCHs), heptachlors, mirex, and endosulfans followed DDTs. Aldrin, dieldrin and endrin, hexachlorobenzene (HCB), and chlordanes were found at very low levels in most matrices and sites, with some exceptions. Considering their potential ecotoxicological risk, most sites would be safe for biota; however, the levels of some OCPs could damage the structure and function of the communities of several coastal sites in a short or long term, mainly in southeastern Brazil and on the coast of the Argentine Pampas. Moreover, it remains to evaluate many sites potentially contaminated by OCPs.

Exposure assessment of toxic metals and organochlorine pesticides among employees of a natural history museum.

Chemical compounds such as arsenic, mercury and organochlorine pesticides have been extensively used as preventive and curative conservation treatments for cultural and biological collections to protect them from pest and mold infestations. Most of the aforementioned compounds have been classified as carcinogenic, mutagenic and teratogenic and represent a health risk for members of staff exposed to contaminated objects. The present study addresses the internal exposure of 28 museum employees in Museum für Naturkunde Berlin by measuring arsenic species and mercury in urine as well as hexachlorocyclohexane isomers (α-HCH, ß-HCH, γ-HCH), hexachlorobenzene (HCB), dichlorodiphenyltrichloroethane (4,4'-DDT) and its main metabolite, dichlorodiphenyldichloroethylene (4,4'-DDE), and pentachlorophenol (PCP) in blood serum. This study was carried out in order to assess the internal exposure of Natural History Museum staff members to toxic metals and organochlorine pesticides. During a working week, two blood samples and five urine samples were taken from each participant, involving 8 women and 20 men. Information about work activity and exposure related factors such as dust development through work, use of personal protective equipment, as well as a nutrition diary were obtained through a questionnaire. Information on fish and seafood intakes as well as amalgam fillings was also available. The results of the study showed that the museum staff members had quantified concentrations of arsenic (median of 6.4 µg/l; maximum of 339 µg/l), mercury (median of 0.20 µg/l; max of 2.6 µg/l), ß-HCH (median of 0.12 µg/l; max of 0.39 µg/l) and 4,4'-DDT (median of 0.050 µg/l; max of 0.82 µg/l). Despite that all the concentrations were below the established reference values, multivariate regression models were able to show that museum staff members are currently exposed to the aforementioned compounds while handling museum objects. To validate our findings, further studies are required.

Geographical distribution and risk assessment of dichlorodiphenyltrichloroethane and its metabolites in Perna viridis mussels from the northern coast of the South China Sea.

Mussels (Perna viridis) were collected from the northern coast of the South China Sea (NSCS) to investigate the geographical distribution and potential risk of dichlorodiphenyltrichloroethane and its metabolites (DDTs). DDTs had concentrations that ranged from 248 ng/g to 4650 ng/g lipid weight (lw), with an average of 807 ± 932 ng/ng lw. A comparison of the levels of DDTs in mussels indicated that the NSCS is still one of the most polluted areas in the world, although a decreasing trend was observed. DDT metabolites were predominant in all samples, suggesting that historical residue was the main source of DDT pollution. However, there were new inputs of DDTs which likely associated with antifouling paints. The human health risk assessment revealed that the current concentrations of DDTs in mussels might pose little health risk for the consumers.