Seasonal change of persistent organic pollutant concentrations in air at Niigata area, Japan

Past, present and future trends of selected pesticidal and industrial POPs in Kuwait

Given the background of current global initiatives for controlling persistent organic pollutants (POPs), an overview of the scientific knowledge about the POPs issues in Kuwait is presented in this study. Both acute and chronic exposure to POPs can be associated with a wide range of deleterious health effects, including illness and death. POPs have drawn significant political and scientific interest in their fate and actions, particularly where local releases have resulted in dispersed contamination far from the source regions. These concerns inevitably led to the establishment of the Stockholm Convention (SC) on POPs. In recent years, Kuwait has carried out a wide variety of environmental research, in particular, on the monitoring of POPs in different matrices. The technological development facilitated to achieve the opposite monitoring of pesticidal and industrial POPs. The majority of these POPs are from a point source. Kuwait does not have pesticide manufacturing facilities and has not produced pesticides for POPs in the past. In the agriculture sector, Kuwait primarily imports pesticides for pest and disease control. This review encompasses the historical presence and current status of (pesticidal) organochlorine pesticides (OCPs) and (industrial POPs) PCBs and PBDEs in Kuwait based on the export, import, consumption and usage. This research also contrasts pesticide and industrial POP data from various Kuwaiti environmental matrices with data from other parts of Asia, the EU, the USA and Africa.

Assessment of organochlorine pesticides in the atmosphere of South Korea: spatial distribution, seasonal variation, and sources

Organochlorine pesticides (OCPs) are widely used in certain countries. We determined atmospheric concentrations, distribution patterns, and seasonal variations of OCPs at four sites in South Korea for 1 year. Samples of 22 OCPs were collected using a high-volume air sampler, and measured via the isotope dilution method with HRGC/HRMS. In South Korea, pentachlorobenzene (PeCB), hexachlorocyclohexane (HCB), and endosulfan (EnSF) were dominant, accounting for > 87% of total OCPs. Spatial distributions showed significant differences and the highest levels were observed in Seosan (295.2 pg·m^-3), indicating the compounding potential of diverse sources as Seosan has concentrated large-scale industrial complexes and agricultural activity (Seoul: 243.6 pg·m^-3 > Jeju: 193.5 pg·m^-3 > Baengnyeong: 178.2 pg·m^-3). The isomeric ratios of OCPs in the South Korean atmosphere indicated that the dominant sources of HCB and dichlorodiphenyltrichloroethane were primarily used in the past; meanwhile, chlordane (CHL) and EnSFs were derived from recent material inputs. Seasonally, OCP concentrations largely peaked in summer with minimum values in winter. This apparent temperature dependence suggests the re-volatilization of accumulated chemicals into the atmosphere. Additionally, an air mass back trajectory indicated the influence of pollutants released from a reservoir through long-range atmospheric transport in the summer. In particular, restricted OCPs are primarily released into the atmosphere by inadvertent sources, such as industrial activities and volatilization from contaminated areas. Thus, severe OCP pollution in Korea is due to the mobile nature of the particles. These data can be useful for the continuous monitoring of long-range transported air pollutants that are transferred between countries.

First report of organochlorine pesticides (OCPs) in coral tissues and the surrounding air-seawater system from the South China Sea: Distribution, source, and environmental fate

The levels, fate, and potential sources of 22 organochlorine pesticides (OCPs) in coral tissues and the surrounding air-seawater system from the South China Sea (SCS) were elucidated for the first time. ∑₂₂OCPs (total concentration of 22 OCPs) (16.1-223 pg L^-1) was relatively higher in coastal seawater than in offshore seawater, which may be the widespread influence of coastal pollution inputs under the western boundary current. The atmospheric ∑₂₂OCPs were predominantly distributed in the gas phase (48.0-2264 pg m^-3) and were mainly influenced by continental air mass origins. The air-seawater exchange of selected OCPs showed that OCPs tended to migrate from the atmosphere to seawater. The distribution of ∑₂₂OCPs in coral tissues (0.02-52.2 ng g^-1 dw) was significantly correlated with that in air samples, suggesting that OCPs may have a migration pattern of atmosphere-ocean corals in the SCS. Corals exhibited higher bioaccumulation ability (Log BAFs: 2.42-7.41) for OCPs. Source analysis showed that the new application of technical Chlordanes (CHLs) was primarily responsible for the current levels of CHLs in the surrounding environment over the SCS, while historical residues were the primary sources of other OCPs.

Factors affecting multiple persistent organic pollutant concentrations in the air above Japan: A panel data analysis

Numerous reports have elucidated different statistical approaches to identify temporal trends in atmospheric persistent organic pollutant (POP) time series. However, the correlation of industrial activity with concentrations of atmospheric POPs in Japan has not yet been determined. Herein, a panel data analysis of a 16-year monitoring program (2003-2018) conducted by the Japanese Ministry of Environment was used to investigate a range of POPs in the atmosphere above Japan. This work focuses on polychlorinated biphenyls (PCBs), polychlorinated naphthalenes (PCNs), polybrominated diphenyl ethers (PBDEs), hexachlorobenzene (HCB), and pentachlorobenzene (PeCBz) collected each year at 53 sites across Japan. The panel analysis revealed that PCB, PCN, and PBDE concentrations were influenced by a combination of factors including year, industrial activity (municipal and industrial waste incinerators, cement kilns, steel industry, and secondary zinc production), population, temperature, and atmospheric boundary layer. However, HCB and PeCBz were not significantly affected by these factors. Industrial activity showed stronger positive correlations with all homologues of PCBs, PCNs, and PBDEs as compared to those demonstrated by population. Significant decreasing trends were identified for the atmospheric ∑PBDEs (half-life t_1/2 = 9.4 years), ∑PCNs (t_1/2 = 8.9 years), and ∑PCBs (t_1/2 = 13.5 years) concentrations, while HCB and PeCBz showed slightly increasing or steady levels. As a statistical tool, panel data analysis can contribute to the assessment of spatial and temporal trends of POPs at a national scale, while elucidating different behavioral responses to numerous environmental variables.

Persistent organic pollutants are still present in surface marine sediments from the Seto Inland Sea, Japan

Although persistent organic pollutants (POPs) are currently banned or strictly controlled under the Stockholm Convention on Persistent Organic Pollutants, POPs are still distributed worldwide due to their environmental persistence, atmospheric transport, and bioaccumulation. Herein we investigated the current concentrations of POPs in the sediments from Seto Inland Sea, Japan and sought to clarify the factors currently controlling the POPs concentration of the surface sediments from Seto Inland Sea. The concentrations of hexachlorocyclohexane isomers (HCHs), dichlorodiphenyltrichloroethane and its metabolites (DDTs), and chlordane isomers (CHLs) in sediments from Seto Inland Sea were <0.002-1.20 ng g^-1, 0.01-2.51 ng g^-1, and 0.01-0.48 ng g^-1, respectively. Resuspension increased the concentrations of HCHs, HCB, and DDTs in the surface sediment with the release of historically contaminated pollutants accumulated in a lower layer. We speculate that CHLs in air that were removed by atmospheric deposition affects the concentration of CHLs in surface sediments.

Selected persistent organic pollutants levels in the Ankara River by months

Persistent organic pollutants (POPs) are banned in almost all countries due to their adverse health effects while they are still present in the environment due to their persistence. As the dissipation and the emission factors of POPs change by temperature and other environmental factors current study aimed to determine selected POPs, including polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and organochlorine pesticides (OCPs) in water and sediment samples collected from 12 stations located in Ankara River, Turkey, for 12 months. C-18 solid-phase extraction technique was used to extract organic pollutants and the analysis were performed using a validated gas chromatography-mass spectrometry method. DDE was the most frequently detected contaminant in water samples. Even though no PCB residues were present in water samples, PCB101 was the most common contaminant in sediment. Although both matrices had the least load of pollutants in winter, there was an increase in presence and concentration of pollutants from late spring to autumn.

Residues and sources of organochlorine pesticides in soils of elementary schools and communities in Wenchuan 5.12 Earthquake-affected areas

The disinfectants and pesticides extensively used after Wenchuan 5.12 Earthquake on May 12, 2008 (so-called Wenchuan 5.12 Earthquake), for epidemic prevention purpose can raise great concerns of environmental pollution and potential personal exposure. To investigate the soil pollution caused by the intensive application in earthquake-affected areas, surface soil samples from two elementary schools, two communities and two background areas were collected in Beichuan County and Dujiangyan City once per location in spring and in autumn in 2011 and then analyzed by gas chromatography/mass spectrometry for organochlorine pesticides (OCPs). The results showed serious soil pollution of hexachlorocyclohexanes (HCHs, 0.05-60.05 ng/g) and dichloro-diphenyl-trichloroethane (DDTs, 0.06-35.79 ng/g) in the study areas compared with Wolong Nature Reserve (0.03-0.81 ng/g for HCHs and 0.02-0.40 ng/g for DDTs). The concentrations of most OCPs in soil of Beichuan County (e.g., 0.10-60.05 ng/g for HCHs and 0.17-35.79 ng/g for DDTs) were much higher than those of Dujiangyan City (e.g., 0.05-20.58 ng/g for HCHs and 0.06-10.69 ng/g for DDTs). In Beichuan County, the highest concentrations of HCHs and DDTs were found in the elementary school. In Dujiangyan City, the highest concentrations of HCHs and DDTs were found in the elementary school and the community, respectively. The concentrations of HCHs and DDTs were generally higher in spring than those in autumn. The predominant species (γ-HCH in ∑HCHs and 4,4'-DDT in ∑DDTs) and specific ratios suggested new inputs of lindane and technical DDT in the study areas. Therefore, continuous soil monitoring and possible intervention would be recommended to minimize local residents' exposure to these toxic chemicals.

Recent decline of DDTs among several organochlorine pesticides in background air in East Asia

Hexachlorocyclohexanes (HCHs), chlordanes (CHLs), and dichlorodiphenyltrichloroethanes (DDTs) in air-mass outflows from East Asia were recorded monthly from April 2009 to March 2014 at Cape Hedo in Japan. These organochlorine pesticides (OCPs) were collected by a high volume air sampler equipped with a quartz fiber filter, a polyurethane foam plug, and activated carbon fiber and analyzed by using a gas chromatograph-high resolution mass spectrometer. The overall (and geometric mean ± SD) concentration over the period was 4.9-43 pg m(-3) (15 ± 7.8 pg m(-3)) in HCHs (sum of α-/β-/γ-/δ-HCH), 1.5-83 pg m(-3) (8.8 ± 11 pg m(-3)) in CHLs (sum of cis-/trans-chlordane, cis-/trans-nonachlor, and oxychlordane), and 0.71-16 pg m(-3) (2.5 ± 2.0 pg m(-3)) in DDTs (sum of o,p'-/p,p'-DDD, o,p'-/p,p'-DDE, and o,p'-/p,p'-DDT). Clear seasonal changes, i.e. higher in summer and lower in winter, were observed in HCHs and CHLs, suggesting the dominant effect of temperature-dependence, secondary sources in these OCPs. DDT concentration as well as the ratio of (o,p'-DDT + p,p'-DDT) to total DDTs, on the other hand, showed clear a declining trend during the five year sampling period, suggesting the decrease of input of newly produced DDTs in the regional environment by reflecting recent activities in the East Asian region to eliminate production and use of DDTs under the Stockholm Convention.

Wet deposition of persistent organic pollutants (POPs) in Izmir, Turkey

Concentrations of several polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), polycyclic aromatic hydrocarbons (PAHs), and polybrominated diphenyl ethers (PBDEs) were measured in precipitation (n = 33) at a suburban site in Izmir, Turkey. Total (dissolved + particle) volume weighted mean (VWM) concentrations for Σ16PAHs, Σ18PCBs, Σ17OCPs, and Σ7PBDEs were 785, 19.2, 50.5, and 29.6 ng l(-1), respectively. Low molecular weight (LMW) compounds (acenaphthylene, fluorene, phenanthrene) and congeners (PCB-18, 28, and 31) dominated the PAH and PCB concentrations, respectively. For PBDEs, BDE-209, and for OCPs, chlorpyrifos, a currently used pesticide, were the predominant compounds. Annual Σ7PBDEs flux was 18.74 μg m(-2) year(-1). PBDE fluxes were mainly in dissolved phase for all congeners except BDE-209 which had comparable proportions in both phases. Annual flux for Σ16PAHs was 497.4 μg m(-2) year(-1); higher molecular weight (MW) PAH fluxes had comparable amounts in both phases while lower MW ones were mostly in dissolved phase. Wet deposition fluxes for Σ18PCBs and Σ17OCPs were 9.40 and 31.94 μg m(-2) year(-1), respectively, and they were predominantly in dissolved phase. Wet deposition fluxes were compared to previously measured annual dry deposition fluxes at the study site to determine their relative contributions to annual total (dry particle + wet) deposition. Dry deposition was the major removal mechanism for most of the PAHs and PCBs contributing >80 % to total (wet + dry) deposition. However, both processes were comparable for PBDEs. Wet deposition was the predominant process for some OCPs such as α-chlordane, γ-chlordane, and trans-nonachlor while both processes were comparable for chlorpyrifos and heptachlor epoxide.

Human health risk assessment and dietary intake of organochlorine pesticides through air, soil and food crops (wheat and rice) along two tributaries of river Chenab, Pakistan

To assess the organochlorine pesticides (OCPs) contamination and their probable hazardous effects on human health; cereal crops (wheat and rice; n=28) agricultural soil (n=28) and air (n=6) samples were collected from Gujranwala division, Punjab Province, Pakistan. ∑OCPs concentration ranged between 123 and 635 pg m(-3), 31 and 365 ng g(-1) (dw), 2.72 and 36.6 ng g(-1) (dw), 0.55 and 15.2 ng g(-1) (dw) for air, soil, rice and wheat samples, respectively. DDTs were the predominant over other OCPSs detected from screened samples while the source apportionment analysis suggested the new inputs of DDTs in the study area. EDI (estimated daily intake) of ∑OCPs through rice and wheat was found 39 and 40 ng kg(-1) day(-1), respectively. Hazard ratios (HRs) on the basis 95th percentile concentrations were exceeding the integrity for most of the investigated OCP in rice and wheat. The results revealed that there is a severe risk to the human population of the study area through consumption of contaminated cereal crops.

Concentrations and relationships between classes of persistent halogenated organic compounds in pooled human serum samples and air from Laizhou Bay, China

Persistent halogenated organic compounds, including polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), polybrominated diphenyl ethers (PBDEs), dechlorane plus (DP), pentabromobenzene (PBBz), and pentabromotoluene (PBT), were analyzed in pooled human serum samples from different age groups and air samples from the south coast of Laizhou Bay, Shandong Province, China. The ∑25OCP and ∑8PBDE congeners were found at higher concentrations than the other compounds, with mean concentrations of 1500 and 240ng/g lipid in serum and 330 and 140,000pg/m(3) in the air, respectively. PBBz and PBT were detected in every serum and air sample, with mean concentrations of 4.9 and 1.4ng/g lipid in serum and 100 and 250pg/m(3) in air, respectively. In serum, the mean concentrations of ∑14PCBs and ∑DP were 7.1 and 3.6ng/g lipid, respectively, and in air, the mean concentrations of ∑12dioxin-like (DL-) PCBs and ∑DP were 1.7 and 1.4pg/m(3), respectively. Different relationships were observed between the concentrations of different compounds in serum and the volunteers' ages, and the concentration distributions with age were closely related to the historic production and usage volumes of each chemical in China. The ubiquity of PCBs, OCPs, PBDEs, DP, PBBz, and PBT in serum and air is potentially concerning, and effective measures should be taken to control the concentrations of these chemicals in the environment and humans. Significant correlations were found between the chemical concentrations in serum and air, suggesting that inhalation may be an important exposure route for the residents of Laizhou Bay.

Distributions, possible sources and biological risk of DDTs, HCHs and chlordanes in sediments of Beibu Gulf and its tributary rivers, China

Thirty-five surface sediment samples collected from Beibu Gulf and its tributary rivers, China were analyzed for DDTs, HCHs and chlordanes. Total concentrations of DDTs, HCHs and chlordanes in sediments ranged from 0.59 to 126 ng g(-)(1), ND to 2.65 ng g(-)(1) and 0.27 to 3.41 ng g(-)(1) based on dry weight (dw), respectively. Concentrations of DDTs were higher than those reported in the sediments from other regions of the world, while concentrations of HCHs and chlordanes were relatively low. High concentrations of DDTs were observed in the harbor region and aquaculture bases and high concentrations of HCHs were found in the Qin River Estuary. The ratios of (DDE+DDD)/DDTs reflected a mixed input of weathered and fresh DDTs. The predominant β-HCH indicated that HCHs in the study area mainly originated from the historical usage of technical HCH. The residues of DDTs would pose adverse biological effects on the study area.

Water-gas exchange of organochlorine pesticides at Lake Chaohu, a large Chinese lake

Organochlorine pesticides (OCPs), a potential threat to ecosystems and human health, are still widely residual in the environment. The residual levels of OCPs in the water and gas phase were monitored in Lake Chaohu, a large Chinese lake, from March 2010 to February 2011. Nineteen types of OCPs were detected in the water with a total concentration of 7.27 ± 3.32 ng/l. Aldrin, DDTs and HCHs were the major OCPs in the water, accounting for 38.3%, 28.9% and 23.6% of the total, respectively. The highest mean concentration (12.32 ng/l) in the water was found in September, while the lowest (1.74 ng/l) was found in November. Twenty types of gaseous OCPs were detected in the atmosphere with a total concentration of 542.0 ± 636.5 pg/m(3). Endosulfan, DDTs and chlordane were the major gaseous OCPs in the atmosphere, accounting for 48.9%, 22.5% and 14.4% of the total, respectively. The mean concentration of gaseous OCPs was significantly higher in summer than in winter. o,p'-DDE was the main metabolite of DDT in both the water and gas phase. Of the HCHs, 52.3% existed as β-HCH in the water, while α-HCH (37.9%) and γ-HCH (30.9%) were dominant isomers in the gas phase. The average fluxes were -21.11, -3.30, -152.41, -35.50 and -1314.15 ng/(m(2) day) for α-HCH, γ-HCH, HCB, DDT and DDE, respectively. The water-gas exchanges of the five types of OCPs indicate that water was the main potential source of gaseous OCPs in the atmosphere. A sensitivity analysis indicated that the water-gas flux of α-HCH, γ-HCH and DDT is more vulnerable than that of HCB and DDE to the variation of the parameters. The possible source of the HCHs in the water was from the historical usage of lindane; however, that in the air was mainly from the recent usage of lindane. The technical DDT and dicofol might be the source of DDTs in the water and air.

Levels, temporal-spatial variations, and sources of organochlorine pesticides in ambient air of Lake Chaohu, China

The residual levels of OCPs in the gas phase and particle phase in Lake Chaohu, China, were measured using GC-MS from March 2010 to February 2011. The temporal-spatial variations and sources of OCPs were also analyzed. Twenty types of OCPs were detected in the gas phase with a total concentration of 484.8 ± 550.4 pg/m³. Endosulfan, DDTs and chlordane were the primary OCPs in the gas phase. The mean concentration of OCPs in the gas phase was significantly higher in the summer than in the winter. Seventeen types of OCPs were detected in the particle phase with a total concentration of 18.3 ± 26.1 pg/m³. DDTs were major OCPs in the particle phase. The mean concentration of OCPs in the particle phase decreased at first and then increased during the period. The potential source of the HCHs in ambient air of Lake Chaohu might come from recent lindane usage. DDTs mainly came from historical dicofol usage, and an input of DDT was observed in the spring, which may result from the present use of marine paint that contains technical DDT. Endosulfan and chlordane in the air may be due to the present use of technical endosulfan and chlordane.

The concentration and distribution of organochlorine pesticides in the air from the karst cave, South China

Organochlorine pesticides (OCPs) in the air of Dayan Cave in Guilin were analyzed, to investigate the source and contamination levels. Generally, air outside of the cave had much higher concentrations than inside air, and both outside and inside air showed much lower contamination levels than those observed in other regions in China and abroad. The ratios of α-/γ-HCHs and the percentages of β-(or δ-)HCH implied a residue of historical local technical HCH contamination. The DDT concentrations, o,p'-DDT/p,p'-DDT, and p,p'-DDE/p,p'-DDT suggested fresh DDT-containing products acted as the primary source of DDT for the air in Dayan Cave. An intermediate level concentration of α-endosulfan (156.00 pg/m(3)) was observed in the outside air, implying local source was dominant. Based on the similar sources of HCH and DDT and the relationships between outside and inside air, it appeared that outside air pollutants affected on inside HCH and DDT's distribution. For other OCPs, outside air might be major contributor to inside air contamination under conditions of high concentrations in outside air compared with low levels in inside air for semi-closed karstic caves.

[Levels and distribution of PCBs and organochlorine pesticides in the air, pine needles, and human milk]

This review presents the findings on the distribution and levels of 20 congeners of polychlorinated biphenyls (PCBs) and 7 organochlorine pesticides (OCPs) all over the world, based on measurements in samples of air, human milk and pine needles. The Institute for Medical Research and Occupational Health has been conducting research in all three matrices for many years, and this review summarises its results too. Significant decrease in concentrations of organochlorine compounds has been seen after the legal ban of their use, but that decresing trend has been slowed down and they are still found in all samples. In general, higher PCB levels are found in samples from urban locations, pesticides levels are higher in samples from locations where has been their probable usage in agriculture, while HCB levels are usually indicator of industrial activity.γ-HCH has been found in the highest concentration in air and pine needles samples, while in humans DDE and β-HCH are the most abundant compounds. Indicator PCB congeners are also differently present in environment and humans: in air and pine needles lower-chlorinated, more volatile PCB congeners have higher concentrations while in humans that goes for more persistent higher-chlorinated PCB congeners. Among toxic ortho-substituted PCB congeners in human and environmental samples the most abundant is PCB-118 while three non-ortho substituted congeners (PCB-77, PCB-126 and PCB-169) that are the most toxic ones are rarely detected. From organochlorine pesticides, DDD is found in lowest concentrations in all samples.

Atmospheric organochlorine pesticide (OCP) levels in a metropolitan city in Turkey

Air concentrations of organochlorine pesticides (OCPs) were measured at four different sites in Bursa, Turkey to determine current levels. For this purpose, about 35 samples were collected from June 2008 to June 2009 using a high volume air sampler (HVAS) equipped with particle and gas-phase units. Ten OCP compounds (alpha-, beta-, gamma-, delta-hexachlorocyclohexane, Heptachlor epoxide, Endrin, Endosulfan beta, Endrin aldehyde, p,p'-DDT and Methoxychlor) were reported within the scope of this study. The average concentrations of total (particle+gas) ∑OCPs were 550.9 ± 277.6 pg m⁻³ (coastal), 1030.7 ± 453.5 pg m⁻³ (urban/traffic), 519.7 ± 277.5 pg m⁻³ (semi-rural) and 722.8 ± 351.8 pg m⁻³ (urban/residential). The individual OCP concentrations were in line with reported concentrations. The maximum particle and gas-phase concentrations were determined for Endosulfan beta and beta-HCH for all sites, respectively. Available gas/particle partitioning models were applied in order to investigate the compatibility of the experimental data and the significant relationships were observed.

Selected organochlorine pesticides in the atmosphere of major Indian cities: levels, regional versus local variations, and sources

India has extensive production and usage of organochlorine pesticides (OCPs) for agriculture and vector control. Despite this, few data are available on the levels and distribution of OCPs in the urban atmosphere of India. Passive and active air sampling was therefore conducted between Dec 2006 and March 2007 in 7 metropolitan cities: New Delhi, Kolkata, Mumbai, Chennai, Bangalore, Goa, and Agra. Concentrations (pg·m(-3)) were as follows: HCHs 890-17000 (mean: 5400 ± 4110); DDTs 250-6110 (1470 ± 1010); chlordanes 290-5260 (1530 ± 790); endosulfans 240-4650 (1040 ± 610); and hexachlorobenzene 120-2890 (790 ± 510). HCHs observed in India appear to be the highest reported across the globe. Chlordanes and endosulfans are lower than levels reported from southern China. Passive sampling enabled within- and between-city variations to be assessed. As expected, paired-sample t-test analysis revealed higher regional than local variation. Comparisons with the limited data available from studies conducted in 1989 suggest general declines of HCHs and DDTs for most regions. γ-HCH dominated the HCH signal, reflecting widespread use of Lindane in India, although the isomeric composition in Kolkata suggests potential technical HCH use. High o,p'-/p,p'-DDT ratios in northern India indicate recent DDT usage. High HCB levels in the industrial areas of New Delhi and Kolkata indicate ongoing sources. Correlation between trans- and cis-chlordane implies ongoing usage. Endosulfan sulfate generally dominated the endosulfan signal, but high values of α/β-endosulfan at Chennai, Mumbai and Goa suggest ongoing usage. Backward trajectories were computed using the NOAA HYSPLIT model to trace the air mass history. Result shows local/regional sources of OCPs within India.

Biomonitoring of organochlorine compounds and trace metals along the Eastern Adriatic coast (Croatia) using Mytilus galloprovincialis

The paper presents the results of monitoring trace organic contaminants (17 PCBs and 7 OCPs) and 6 trace metals (Cd, Cr, Cu, Hg, Pb and Zn) in the coastal waters of the eastern Adriatic in 2006 using Mytilus galloprovincialis as indicator species. OCPs were found in all samples (0.07-14.3 ng g(-1)d.wt.), while in positive samples concentrations of PCBs ranged between 0.16 and 20.5 ng g(-1)d.wt. The α-HCH/γ-HCH and DDE/DDT ratios indicated recent input of γ-HCH and DDT. Spatial distributions of HCB, PCBs, DDTs and Hg were significantly correlated with population density. Although elevated concentrations of all trace metals and organic contaminants were recorded in the densely populated and industrialized areas, overall data point to relatively low level of contamination of the eastern Adriatic coast. Evaluation of the risks to human health associated with consumption of the mussels suggested that there is no health risk for moderate shellfish consumers.

Semi-volatile organic compounds (SVOCs) in ambient air and rainwater in a tropical environment: concentrations and temporal and seasonal trends

The levels of a range of SVOCs (PAHs, OCPs, and PCBs) in atmospheric particulate and gaseous phases and rainwater samples were studied in Singapore from June 2007 to May 2008. Yearly average concentrations of PAHs, OCPs and PCBs in air (particle+gas) were 136.5 ng m(-3), 695.8 pg m(-3) and 27 pg m(-3), respectively while those of PAHs and OCPs in rainwater (particulate+dissolved) were 1218.1 and 114.2 ng L(-1), respectively. The lower molecular weight (LMW) PAHs were more abundant than those higher molecular weight (HMW) PAHs in rainwater. Among OCPs, HCHs were found in rainwater in relatively larger amounts than DDTs. Similar distributions patterns were also found in air samples. Statistical correlation analysis indicated that the atmospheric occurrence of SVOCs had positive correlation with ambient temperature except for particulate PAHs and negative correlations with relative humidity and wind speed; incoming solar radiation (SR) was negatively associated with PAHs, but there was almost no correlation between SR and the occurrence of OCPs and PCBs. ANOVA analysis revealed that the temporal variations were statistically significant for PAHs and PCBs in air samples and for OCPs in rainwater. In addition, local traffic emissions, trans-boundary transport of pesticides from regional sources and Aroclors 1248 and 1254 were identified as probable sources for PAHs, OCPs and PCBs in the atmosphere, respectively, based on molecular diagnostic ratios and principal component analysis (PCA) together with the assistance of air mass backward trajectories.

Hexachlorobenzene sources, levels and human exposure in the environment of China

This article summarizes the published scientific data on sources, levels and human exposure of hexachlorobenzene (HCB) in China. Potential sources of unintended HCB emission were assessed by production information, emission factors and environmental policies. HCB was observed in various environmental compartments in China. HCB levels increased from South China to North China in most of environmental compartments (air, soil and mussel). Some hotspots were identified near the factories producing and using HCB. In terms of spatial distribution, HCB concentrations in air and shellfish showed much variation, which indicated some primary emission sources in China. HCB levels in air and human milk in China were relatively higher than those in other countries, but HCB levels in other compartments were similar to those in Europe and other countries in Eastern Asia. In the limited studies on temporal trends of HCB levels in China, HCB concentrations in air, sediment, fish and human milk did not show a consistent downward trend. Although HCB levels in food and human milk does not pose a health risk in China at present, long-term exposure to HCB should not be overlooked.

Persistent organochlorine compounds in human milk collected in Croatia over two decades

The distribution and time trend of organochlorine pesticide (OCP), polychlorinated biphenyl (PCB), and polychlorinated dibenzo-p-dioxin/polychlorinated dibenzofuran (PCDD/PCDF) concentrations in human milk samples from Croatia collected in 1981-2003 are presented. Between 1981/1982 and 1987/1989, the concentrations of HCB, beta-HCH, DDE, and total PCBs decreased about 50%, while for the last decade, the concentrations have been decreasing very slowly. In 2002/2003 the range of PCB congeners and OCPs was from below the limit of determination to 332 ng g(-1) milk fat. PCDD/PCDF concentrations in human milk samples collected in 1981-2000 ranged between 5.2 and 26.7 pg I-TEQ g(-1) milk fat and showed a decreasing trend.

Determination of semi-volatile organochlorine compounds in the atmosphere of Singapore using accelerated solvent extraction

Accelerated solvent extraction (ASE) has been applied to the quantitative extraction of organochlorine compounds (OCs), including organochlorine pesticides (HCHs, DDXs) and polychlorinated biphenyls (PCBs) present in both atmospheric particulate and gaseous phase. Extraction parameters such as the combination of solvents, extraction temperature, and static extraction time were investigated and optimized. Effective extraction can be carried out using a 3:1 mixture of n-hexane and acetone as extraction solvents at 100 degrees C in 20min for all the compounds studied. The entire analytical procedure developed in this study proves to be reliable as evident from the analysis of specific surrogate standards with the mean recoveries per sample being greater than 82%. The optimized method was validated using NIST-certified SRM 1649a. Semi-volatile OCs, in the atmosphere of Singapore were quantified using the optimized ASE method together with GC-MS. Total average concentrations of SigmaHCHs, SigmaDDXs, and SigmaPCBs in air samples were 244.9+/-88.5pgm(-3), 7.7+/-4.1pgm(-3), and 34.1+/-19.7pgm(-3), respectively. The distribution of these compounds between the gas and particulate phase is discussed. Possible sources of atmospheric OCs are evaluated based on the molecular ratio of specific compounds and backward air trajectory analysis.

Are pine needles bioindicators of air pollution? Comparison of organochlorine compound levels in pine needles and ambient air

Levels of six PCB congeners and seven organochlorine pesticides were investigated and compared in ambient air and in pine needle samples. The applied methods are suitable for the analysis of PCBs and organochlorine pesticides in environmental samples and for their detection in recent intakes. DDE, HCB, lindane, PCB-28, PCB-52, PCB-101, PCB-138 and PCB-153 were found in all pine needle and air samples. The highest median values were found for PCB-28, PCB-101 and gamma-HCH, and the lowest for PCB-180 and DDD. The median value of alpha-HCH/ gamma-HCH ratios was 0.2 in both matrices. DDE/DDT ratios were close to or below 1 in some pine needle and ambient air samples. The results showed a correspondence between air and pine needle pollution; the same compounds were present in the highest or in the lowest levels in both types of matrices. These results suggest that pine needles are passive biomonitors of air pollution.

Biodegradation of chlordane and hexachlorobenzenes in river sediment

Contamination of river sediments by persistent organic pollutants (POPs) is a worldwide concern, and microbial degradation is regarded as an important process for removal of POPs from river sediments. To date, there is still a lack of systematic study on chlordane biodegradation in river sediments, and the information on hexachlorobenzene (HCB) biodegradation in river sediments is very limited in Japan. We investigated the anaerobic biodegradation potential of trans-chlordane (TC), cis-chlordane (CC), and HCB in sediment samples collected at three sites along the Kamogawa River in Saitama Prefecture, Japan. Lag period and biodegradation rates of TC and CC in the three sediments varied greatly with their properties and contamination by TC and CC. In contrast, biodegradation of HCB in all three sediments started immediately with the start of the experiment without lag period, and major differences in biodegradation rates among the sediments were not observed. At the end of 20-week anaerobic incubation in the dark at 30 degrees C temperature, degradation rates ranged from 0.0% to 33.0% for TC, 0.0% to 12.0% for CC, and 47.6% to 59.4% for HCB. Results showed that the high-to-low order of biodegradation in the river sediments was HCB>TC>CC. Although the sediments were collected in the same river, their biodegradation potential varied with properties. Sediment with rich organic content and contamination by TC and CC or HCB was observed to have high biodegradation rates for these pollutants. In addition, biodegradation of TC, CC and HCB was companied by obvious methane generation and drop of oxidation-reduction potential (ORP).

Simultaneous Monitoring Method of Polycyclic Aromatic Hydrocarbons and Persistent Organic Pollutants in the Atmosphere Using Activated Carbon Fiber Filter Paper

In order to simultaneously monitor the concentrations of PAHs and POPs in the atmosphere, an activated carbon fiber filter paper (ACFP) was used as the adsorbing material in this study. The pressurized liquid extraction method (PLE method) was used to extract PAHs and POPs collected on the ACFP. Toluene was an effective solvent to extract them from ACFP using the PLE method, but some of PAHs, such as benzo(a)pyrene, benzo(g,h,i)perylene, dibenzo(a,h)anthracene and indeno(1,2,3-cd)pyrene, were hardly extracted. These PAHs were adsorbed on the particulate matter in the atmosphere. In general, these forms of particulate matter could be collected using a quartz fiber paper (QFP); these PAHs were efficiently extracted from the QFP using the PLE method with toluene. In this study, the collecting method of the PAHs was modified by using QFP overlapped in front of the ACFP. Atmospheric monitoring of PAHs and POPs in Niigata area was performed using this method, and most of the target compounds were detected. However, some of the POPs, such as aldrin, endrin, mirex, could not be detected. The POPs, such as hexachlorobenzene, alpha-hexachlorocyclohexane and chlordanes, and most of the PAHs were detected from all of the samples collected throughout the monitoring period. It was confirmed that these methods were effective to simultaneously monitor the concentrations of the PAHs and POPs in the atmosphere.

Hexachlorobenzene in the global environment: emissions, levels, distribution, trends and processes

Hexachlorobenzene (HCB) is considered here as a 'model persistent organic pollutant.' Data on its sources, emissions, environmental levels and distributions and trends are compiled and used to assess its fate and behaviour in the global environment. Consideration is given as to the extent to which it has undergone repeated air-surface exchange or 'hopping' to become globally dispersed, the balance between primary and secondary sources in maintaining ambient levels, and its ultimate sinks in the environment. Global production exceeded 100,000 tonnes and primary emissions to atmosphere probably peaked in the 1970s. There has been a consistent downward trend in the environment over the past 20 years. Temporal trends of HCB in the environment vary, dependent on time period measured, media studied and study location, but the average half-life from all the studies is approximately 9 years. Estimates are made of the contemporary burden in the environment; these range between 10,000 and 26,000 tonnes and are dominated by the loadings in treated and background soils, sediments and oceans. Estimates of the trends of HCB emissions from treated soils are derived. At its peak, the amount of HCB emitted from soil to air may have been in the hundreds to thousands of tonnes per year, which would have made it a significant source of HCB to the environment. Whilst the amount of HCB being emitted from contemporary soil is much lower, only a small amount of re-emission of HCB from soil to air is required to maintain contemporary air concentrations under the current primary emission scenario.