Organochlorine pesticides (OCPs) in South Asian region: a review

Advanced technologies for the remediation of pesticide-contaminated soils

The occurrence of pesticides in soil has become a highly significant environmental problem, which has been increased by the vast use of pesticides worldwide and the absence of remediation technologies that have been tested at full-scale. The aim of this review is to give an overview on technologies really studied and/or developed during the last years for remediation of soils contaminated by pesticides. Depending on the nature of the decontamination process, these techniques have been included into three categories: containment-immobilization, separation or destruction. The review includes some considerations about the status of emerging technologies as well as their advantages, limitations, and pesticides treated. In most cases, emerging technologies, such as those based on oxidation-reduction or bioremediation, may be incorporated into existing technologies to improve their performance or overcome limitations. Research and development actions are still needed for emerging technologies to bring them for full-scale implementation.

First report on organochlorine pesticides in water in a highly productive agro-industrial basin of the Central Valley, Chile

The Ñuble River flows through an agricultural area in the central zone of Chile in which different types of fruits are grown. The objective of this study was to identify the levels and source of organochlorine pesticides (OCPs) in the surface waters of the Ñuble River. Surface water samples were collected at 10 sampling points and analyzed for 19 organochlorine pesticides during the dry (spring-summer) and wet (autumn-winter) periods of 2013 and 2014. The results revealed that concentrations of total OCPs in surface waters ranged from 0.12 to 26.28 ng/l. Endosulfan and lindane were the main OCPs in the water. The maximum OCP levels were found in the dry period, while significantly lower concentrations were recorded in the wet period. This indicates that patterns of OCPs have varied in the last 10 years as this study found low concentrations of DDT and metabolites but significantly increased concentrations of α-endosulfan. Given the fact that OCPs were withdrawn from agricultural used many years ago, their presence indicates that they may be still in use clandestinely. Findings of significant concentrations of endosulfan and lindane in this study lead to the conclusion that the chemical fallow practices contribute to runoff into the river and surface water infiltration into groundwater. Because no studies have previously measured OCP levels in agricultural basins in Chile, this study is an important contribution to the knowledge of organochlorine contaminants present in surface water in Chile.

Distribution and enantiomeric profiles of organochlorine pesticides in surface sediments from the Bering Sea, Chukchi Sea and adjacent Arctic areas

The spatial distribution, compositional profiles, and enantiomer fractions (EFs) of organochlorine pesticides (OCPs), including hexachlorocyclohexanes (HCHs), dichlorodiphenyltrichloroethanes (DDTs), and chlordanes (CHLs), in the surface sediments in the Bering Sea, Chukchi Sea and adjacent areas were investigated. The total concentrations of DDTs, HCHs and CHLs varied from 0.64 to 3.17 ng/g dw, 0.19-0.65 ng/g dw, and 0.03-0.16 ng/g dw, respectively. No significant difference was observed between the Bering Sea and Chukchi Sea for most pollutants except for trans-CHL, ΣCHLs (sum of trans- and cis-chlordane) and p,p'-DDD. Concentration ratios (e.g., α-HCH/γ-HCH, o,p'-DDT/p,p'-DDT) indicated that the contamination in the studied areas may result from inputs from multiple sources (e.g., historical usage of technical HCHs as well as new input of dicofol). Chiral analysis showed great variation in the enantioselective degradation of OCPs, resulting in excess of (+)-enantiomer for α-HCH in thirty of the 32 detectable samples, preferential depletion of (-)-enantiomer for o,p'-DDT in nineteen of the 35 detectable samples, and nonracemic in most samples for trans- and cis-chlordane. The ecological risks of the individual OCPs as well as the mixture were assessed based on the calculation of toxic units (TUs), and the results showed the predominance of DDT and γ-HCH in the mixture toxicity of the sediment. Overall, the TUs of OCPs in sediments from both the Bering and Chukchi Seas are less than one, indicating low ecological risk potential.

National investigation of semi-volatile organic compounds (PAHs, OCPs, and PCBs) in lake sediments of China: Occurrence, spatial variation and risk assessment

In this study, a large scale investigation of semi-volatile organic compounds (SVOCs) in sediments from 52 lakes, located in five geographic regions across China, was conducted to assess sediment quality in terms of organic contaminants. Concentrations of polycyclic aromatic hydrocarbons (PAHs), organochlorine pesticides (OCPs), and polychlorinated biphenyls (PCBs) in sediment were found to range between 17.00-6,633, 0.12-45.24, and 0.03-13.99ngg^-1, respectively. Lake sediments from different regions exhibited variation in contamination levels, and in the compositions of isomers. The descending order of contamination levels for the three SVOCs groups (i.e., ∑PAHs, ∑OCPs, ∑PCBs) were as follows: the eastern plain region (EPR)>the Yunnan-Guizhou plateau (YGP)>the northeast China region (NCR)>the Qinghai-Tibet plateau (QTP)>the Mongolia-Xinjiang plateau (MXP). High molecular weight PAHs, OCPs and PCBs were found at high concentrations in parts of the EPR and YGP, while lighter isomers were likely to be atmospherically transported, resulting in their nationwide distribution. The sources and type variation (local input or atmospheric deposition) are the primary controls of spatial variation. Additionally, human related socio-economic factors, and geographic conditions also played important roles in influencing the spatial differentiation. According to simple sediment quality guidelines (SQG), the risks posed by PCBs in sediments were not as serious as those posed by PAHs and DDT.

A Review on the Abundance, Distribution and Eco-Biological Risks of PAHs in the Key Environmental Matrices of South Asia

Polycyclic aromatic hydrocarbons (PAHs) are consistently posing high risks to human/biota in developing countries of South Asia where domestic areas are exposed to biomass burning and commercial/industrial activities. This review article summarized the available data on PAHs occurrence, distribution, potential sources and their possible risks in the key environmental matrices (i.e., Air, Soil/Sediments, Water) from South Asian Region (SAR). Available literature reviewed suggested that PAHs concentration levels were strongly influenced by the monsoonal rainfall system in the region and it has been supported by many studies that higher concentrations were measured during the winter season as compared to summer. Biomass burning (household and brick kilns activities), open burning of solid wastes and industrial and vehicular emissions were categorized as major sources of PAHs in the region. Regional comparison revealed that the contamination levels of PAHs in the water bodies and soil/sediments in SAR remained higher relatively to the reports from other regions of the world. Our findings highlight that there is still a general lack of reliable data, inventories and research studies addressing PAHs related issues in the context of environmental and human health in SAR. There is therefore a critical need to improve the current knowledge base, which should build upon the research experience from other regions which have experienced similar situations in the past. Further research into these issues in South Asia is considered vital to help inform future policies/control strategies as already successfully implemented in other countries.

Monitoring of organochlorine pesticides in blood of women with uterine cervix cancer

In Yucatan, Mexico, chronic exposure of Mayan population to pesticides is expected as about 30 per cent are drinking polluted water. Residues of organochlorine pesticides (OCP) were monitored in 18 municipalities of Yucatan with high mortality rates due to uterine cervix cancer. 70 blood samples collected from Mayan women living in livestock, agricultural and metropolitan area were analyzed for OCP. Solid Phase Extraction was performed on C18 cartridges and analyzed by Gas Chromatography with Electron Capture Detector. The results showed that the highest OCP levels were detected in blood of women living in the livestock area. OCP detected were endosulfan I (7.35 μg/mL), aldrin (3.69 μg/mL), 4,4' DDD (2.33 μg/mL), 1.39 and 1.46 μg/mL of δ-HCH. Women from the agricultural area had high concentrations of OCP in their blood, particularly dieldrin (1.19 μg/mL), and 1.26 μg/mL of 4,4' DDE. In the metropolitan area, 0.080 μg/mL of γ-HCH and 0.064 μg/mL of heptachlore were detected. This monitoring study was also based on epidemiological data of uterine cervical cancer. It was found that environmental factors may have facilitated the infiltration of OCP to the aquifer used for potable water supply. These factors in addition to poverty can have impacts on public health. This first exploratory study suggests that monitoring of OCP in human is important for the establishment of health promotion programs. The integrative analysis of both, environmental and social factors would be helpful to characterize the bioaccumulation of pesticides in humans.

Distributions of organochlorine compounds in sediments from Jiulong River Estuary and adjacent Western Taiwan Strait: Implications of transport, sources and inventories

Estuaries and coastal areas strongly influenced by terrestrial inputs resulted from anthropogenic activities. To study the distributions, origins, potential transport and burden of organochlorine compounds (OCs) from river to marginal sea, organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) were investigated in surface sediments collected from a subtropical estuary (Jiulong River Estuary, JRE) and the inner shelf of adjacent Western Taiwan Strait (WTS). The concentrations of OCPs and PCBs were from 5.2 to 551.7 and 1.0-8.1 ng g^-1 (dry weight), respectively. OCP concentrations in the JRE were higher than in adjacent WTS, and a decreasing trend with the ascending distance from the estuary to the open sea was observed. Concentrations of DDTs were quite high in the upper reach of the estuary, inferred from antifouling paint on fishing boats of a local shipping company. According to established sediment quality guidelines, DDTs in the JRE posed potential ecological risk. HCHs in the estuary were mainly derived from the weathered HCHs preserved in the agriculture soils via local major river runoffs. OCPs patterns showed that OCPs in the south coast of WTS were resulted from local sources via river input, while OCPs in the north coast attributed to the long-range transport derived by the Fujian-Zhejiang Coastal Current. Minor variations of PCB concentrations and homologs indicated that PCBs were not the main pollutant in the agricultural region, consistent lighter PCBs reflected industrial PCBs were transported via atmospheric deposition derived by East Asia Monsoon. Moreover, the primary distribution pattern founded for DDTs and the considerable mass inventories and burdens calculated (258.1 ng cm^-2 and 10.4 tones for OCPs) that higher than Pearl River Delta and Yangtze River Delta, together suggested that the contaminated sediments in the study area may be a potential source of OCPs to the global ocean.

Biodegradation of malathion, α- and β-endosulfan by bacterial strains isolated from agricultural soil in Veracruz, Mexico

The objective of this study was to evaluate the capacity of two bacterial strains isolated, cultivated, and purified from agricultural soils of Veracruz, Mexico, for biodegradation and mineralisation of malathion (diethyl 2-(dimethoxyphosphorothioyl) succinate) and α- and β-endosulfan (6,7,8,9,10,10-hexachloro-1,5,5a,6,9,9a-hexahydro-6-9-methano-2,4,3-benzodioxathiepine-3-oxide). The isolated bacterial strains were identified using biochemical and morphological characterization and the analysis of their 16S rDNA gene, as Enterobacter cloacae strain PMM16 (E1) and E. amnigenus strain XGL214 (M1). The E1 strain was able to degrade endosulfan, whereas the M1 strain was capable of degrading both pesticides. The E1 strain degraded 71.32% of α-endosulfan and 100% of β-endosulfan within 24 days. The absence of metabolites, such as endosulfan sulfate, endosulfan lactone, or endosulfan diol, would suggest degradation of endosulfan isomers through non-oxidative pathways. Malathion was completely eliminated by the M1 strain. The major metabolite was butanedioic acid. There was a time-dependent increase in bacterial biomass, typical of bacterial growth, correlated with the decrease in pesticide concentration. The CO₂ production also increased significantly with the addition of pesticides to the bacterial growth media, demonstrating that, under aerobic conditions, the bacteria utilized endosulfan and malathion as a carbon source. Here, two bacterial strains are shown to metabolize two toxic pesticides into non-toxic intermediates.

Use of feathers to assess polychlorinated biphenyl and organochlorine pesticide exposure in top predatory bird species of Pakistan

Little is known about the levels of organochlorines (OCs) in predatory bird species from Asia or the factors governing their concentrations. This study is the first report on concentrations of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in predatory birds of Pakistan. The concentrations of PCBs and OCPs were investigated using tail feathers of ten different species of predatory birds. In addition, concentration differences among body, tail, primary and secondary feathers were investigated for six individuals of black kite (Milvus migrans). Ranges of concentrations were highest for dichlorodiphenyldichloroethylene (p,p'-DDE: 0.11-2163ngg(-1) dry wt.) followed by dichlorodiphenyltrichloroethane (p,p'-DDT: 0.36-345ngg(-1) dry wt.), hexachlorobenzene (HCB: 0.02-34ngg(-1) dry wt.), ∑PCBs (0.03-16ngg(-1) dry wt.) and trans-nonachlor (TN; 0.01-0.13ngg(-1) dry wt.). CB 118, 153, 138, and 180 along with p,p'-DDE were found as the most prevalent compounds. ∑PCBs and ∑DDTs were significantly different among species (both p<0.01) and omnivorous, scavengers, carnivorous and piscivorous trophic guilds (all p<0.03). Only ∑PCBs were significantly differentamong different families of birds (p<0.01). Values of stable isotopes (δ(13)C and δ(15)N) differed significantly (all p<0.01) among species, families, trophic guilds as well as terrestrial and aquatic habitat but not between nocturnal and diurnal predators (p=0.22 for δ(13)C; p=0.50 for δ(15)N). Concentrations of ∑PCBs, ∑DDTs and trans-nonachlor, but not HCB (p=0.86), were significantly different among different feather types (all p<0.01). Trophic and taxonomic affiliation as well as dietary carbon sources (δ(13)C) for species were identified as the variables best explaining the observed variation in exposure to the studied compounds. The significance of contributing factors responsible for OC contamination differences in predatory birds should be further elucidated in future studies.

Evaluating genotoxic risks in Brazilian public health agents occupationally exposed to pesticides: a multi-biomarker approach

This is the first study demonstrating genotoxic effects and whole transcriptome analysis on community health agents (CHAs) occupationally exposed to pesticides in Central Brazil. For the transcriptome analysis, we found some genes related to Alzheimer's disease (LRP1), an insulin-like growth factor receptor (IGF2R), immunity genes (IGL family and IGJ), two genes related to inflammatory reaction (CXCL5 and CCL3), one gene related to maintenance of cellular morphology (NHS), one gene considered to be a strong apoptosis inductor (LGALS14), and several transcripts of the neuroblastoma breakpoint family (NBPF). Related to comet assay, we demonstrated a significant increase in DNA damage, measured by the olive tail moment (OTM), in the exposed group compared to the control group. Moreover, we also observed a statistically significant difference in OTM values depending on GSTM1 genotypes. Therefore, Brazilian epidemiological surveillance, an organization responsible for the assessment and management of health risks associated to pesticide exposure to CHA, needs to be more proactive and considers the implications of pesticide exposure for CHA procedures and processes.

A meta-analysis synthesizing the effects of pesticides on swim speed and activity of aquatic vertebrates

Pesticide contaminants are ubiquitous in aquatic environments and pose a threat to biodiversity. Pesticides also have diverse mechanisms of action that make it difficult to identify impacts on exposed wildlife. Behavioral measures represent an important link between physiological and ecological processes, and are often used to generalize sub-lethal effects of pesticide exposure. In order to bridge the toxicological and behavioral literature, and identify chemical classes that denote the largest threat, we conducted a meta-analysis summarizing the effects of pesticides on swim speed and activity of aquatic vertebrates. We found that exposure to environmentally relevant concentrations of pesticides reduced the swim speed of exposed amphibians and fish by 35%, and reduced overall activity by 72%. There were also differences in the magnitude of this effect across chemical classes, which likely reflect underlying physiological processes. Pyrethroids, carbamates, and organophosphates all produced a large decrease in swim speed, where as phosphonoglycines and triazines showed no overall effect. Pyrethroids, carbamates, organophosphates, organochlorines, and organotins also produced a large decrease in activity, while phosphonoglycines had no overall effect, and triazines had the opposite effect of increasing activity. Our results indicate that even sub-lethal concentrations of pesticides have a strong effect on critical behaviors of aquatic vertebrates, which can affect fitness and alter species interactions. We expect our synthesis can be used to identify chemical classes producing the largest sub-lethal effects for further research and management.

An assessment of the impacts of pesticide use on the environment and health of rice farmers in Sierra Leone

One of the biggest challenges faced by Sierra Leonean farmers is pest control. Birds, rodents, insects, crustaceans and other organisms can drastically reduce yields. In order to prevent these organisms from destroying their crop, farmers use pesticides. However there are reports that these chemicals are being misused and such misuse is having a negative impact on the environment and the health of the farmers. This research study aimed to investigate the use of pesticides in rice fields and its potential effects on the environment and on the farmers of Sierra Leone. Five hundred farmers and one hundred health workers across the country were interviewed. Fifty focus group discussions were also completed. Field observations were also undertaken to see how farmers apply pesticides to their farms and the possible threats these methods have on human health and the environment. It is clear that a wide range of pesticides are used by rice farmers in Sierra Leone with 60% of the pesticides used entering the country illegally. Most farmers have no knowledge about the safe handling of pesticides as 71% of them have never received any form of training. The pesticides kill both target and non-target organisms some of which enter the food chain. Cases of health problems such as nausea, respiratory disorders and blurred vision investigated in this research are significantly higher among farmers who use pesticides than those who do not use pesticides. Cases of pesticide intoxication are not investigated by health workers but results obtained from interviews with them also indicated that cases of pesticides related symptoms are significantly higher in environments where pesticides are used than those in which pesticides are not used.

Waste dumping sites as a potential source of POPs and associated health risks in perspective of current waste management practices in Lahore city, Pakistan

Persistent organic pollutants (POPs) including polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and dechloran plus (DP) were analyzed in air, dust, soil and water samples from waste dump site, Lahore, Pakistan. It was revealed that PCB levels were detected higher in all matrices than PBDEs and DPs. Principal Component Analysis (PCA) showed higher usage of BDE-47, -99 and di-CBs, tri-CBs, tetra-CBs and penta-CBs. Health risk assessment of PCBs and PBDEs from soil and dust indicated low to moderate risk to the local population via different exposure pathways. It is recommended to improve current waste management practices in order to avoid emissions of contaminants and open dumping grounds should be modified into sanitary landfill.

Induction of DNA damage and erroneous repair can explain genomic instability caused by endosulfan

Endosulfan (ES) is an organochlorine pesticide, speculated to be associated with chromosomal abnormalities and diseases in humans. However, very little is known about the mechanism of its genotoxicity. Using in vivo, ex vivo and in vitro model systems, we show that exposure to ES induces reactive oxygen species (ROS) in a concentration and time-dependent manner. The generation of ROS results in DNA double-strand breaks either directly or in a replication-dependent manner, both in mice and human cells. Importantly, ES-induced DNA damage evokes DNA damage response, resulting in elevated levels of classical non-homologous DNA endjoining (NHEJ), the predominant double-strand break repair pathway in higher eukaryotes. Sequence analyses of NHEJ junctions revealed that ES treatment results in extensive processing of broken DNA, culminating in increased and long junctional deletions, thereby favoring erroneous repair. We also find that exposure to ES leads to significant increase in microhomology-mediated end joining (MMEJ), a LIGASE III-dependent alternative repair pathway. Therefore, we demonstrate that ES induces DNA damage and genomic instability, alters DNA damage response thereby promoting erroneous DNA repair.

Persistent Organic Pollutants in albacore tuna (Thunnus alalunga) from Reunion Island (Southwest Indian Ocean) and South Africa in relation to biological and trophic characteristics

The contamination of albacore tuna (Thunnus alalunga) by Persistent Organic Pollutants (POPs), namely polychlorinated biphenyls (PCBs) and dichlorodiphenyl-trichloroethane (DDT), was investigated in individuals collected from Reunion Island (RI) and South Africa's (SA) southern coastlines in 2013, in relation to biological parameters and feeding ecology. The results showed lower PCB and DDT concentrations than those previously reported in various tuna species worldwide. A predominance of DDTs over PCBs was revealed, reflecting continuing inputs of DDT. Tuna collected from SA exhibited higher contamination levels than those from RI, related to higher dietary inputs and higher total lipid content. Greater variability in contamination levels and profiles was identified in tuna from RI, explained by a higher diversity of prey and more individualistic foraging behaviour. PCB and DDT contamination levels and profiles varied significantly in tuna from the two investigated areas, probably reflecting exposure to different sources of contamination.

Organochlorine pesticides (OCPs) in the Indus River catchment area, Pakistan: Status, soil-air exchange and black carbon mediated distribution

Organochlorine pesticides (OCPs) were investigated in passive air and soil samples from the catchment area of the Indus River, Pakistan. ∑15OCPs ranged between 0.68 and 13.47 ng g(-1) in soil and 375.1-1975 pg m-(3) in air. HCHs and DDTs were more prevalent in soil and air compartments. Composition profile indicated that β-HCH and p,p'-DDE were the dominant of all metabolites among HCHs and DDTs respectively. Moreover, fBC and fTOC were assessed and evaluated their potential role in the distribution status of OCPs. The fTOC and fBC ranged between 0.77 and 2.43 and 0.04-0.30% respectively in soil. Regression analysis showed the strong influence of fBC than fTOC on the distribution of OCPs in the Indus River catchment area soil. Equilibrium status was observed for β-HCH, δ-HCH, p,p'-DDD, o,p'-DDT, TC, HCB and Heptachlor with ff ranged between 0.3 and 0.59 while assessing the soil-air exchange of OCPs.

Significance of black carbon in the sediment-water partitioning of organochlorine pesticides (OCPs) in the Indus River, Pakistan

This study was conducted with the aim of assessing the levels and black carbon mediated sediment-water partitioning of organochlorine pesticides (OCPs) from the Indus River. ∑OCPs ranged between 52-285 ng L(-1) and 5.6-29.2 ng g(-1) in water and sediment samples respectively. However, the ranges of sedimentary fraction of total organic carbon (f(TOC)) and black carbon (f(BC)) were 0.82-2.26% and 0.04-0.5% respectively. Spatially, OCPs concentrations were higher at upstream sites as compared to downstream sites. Source diagnostic ratios indicated the technical usage of HCH (α-HCH/γ-HCH>4) and significant presence of DDT metabolites with fresh inputs into the Indus River as indicated by the ratios of (DDE+DDD)/∑DDTs (0.27-0.96). The partitioning of OCPs between the sediments and water can be explained by two carbon Freundlich adsorption model which included both organic carbon and black carbon pools as partitioning media.

Presence, deposition flux and mass burden of persistent organic pollutants (POPs) from Mehmood Booti Drain sediments, Lahore

This study was conducted with the aim of analyzing persistent organic pollutants i.e., PCBs, PBDEs, DPs and OCPs for sediment samples collected from Mehmood Booti Drain, Lahore, Pakistan that receives higher pollution loads from adjacent waste dumping site. Levels of ∑PCBs, ∑PBDEs, ∑DPs and ∑OCPs ranged between 5.9-62, 0.36-1.32, n.d.-0.02 and 0.96-18.07ngg(-1,) respectively. These levels were found to be comparable with other studies of local or global origin. Composition, spatial distribution and source profile indicated that Mehmood Booti waste dumping site was the major input source for sedimentary POPs pollution. The highest POPs deposition flux and mass inventory was attributed to PCBs and OCPs. Deposition flux indicated the input of 6E(-04), 5E(-05), 9E(-07) and 4E(-0)(4)t/yr of PCBs, PBDEs, DPs and OCPs into the Mehmood Booti Drain sediments which ultimately discharge into the River Ravi. Mass inventories suggested 1E(-02), 3E(-04), 7E(-06) and 3E(-03) metric tons PCBs, PBDEs, DPs and OCPs burden, respectively in the Mehmood Booti Drain sediments.

POP and PAH contamination in the southern slopes of Mt. Everest (Himalaya, Nepal): Long-range atmospheric transport, glacier shrinkage, or local impact of tourism?

Due to their physico-chemical properties, POPs and PAHs are subjected to long-range atmospheric transport (LRAT) and may be deposited in remote areas. In this study, the contamination with DDx, PCBs, PBDEs, and PAHs was investigated in sediments and soils collected on the southern slopes of Mt. Everest (Himalaya, Nepal) in two different sampling campaigns (2008 and 2012). The results showed a limited contamination with POPs and PAHs in both soil and sediment samples. Therefore, the southern slopes of Mt. Everest can be considered a remote area in almost pristine condition. The LRAT mechanism confirmed its primary role in the transfer of contaminants to remote regions, while the gradual melting of glaciers, due to global warming, and the subsequent release of contaminants was suggested to be a secondary source of pollution of the lake sediments. In addition, the increase of tourism in this area during the last decades might have influenced the present concentrations of PAHs in the sediments and soils.

A review on current knowledge and future prospects of organohalogen contaminants (OHCs) in Asian birds

The release of harmful chemicals in the Asian environment has recently increased dramatically due to rising industrial and agricultural activities. About 60% of the global human population is currently living on the Asian continent and may thus be exposed to a large range of different chemicals. Different classes of organohalogen chemicals have indeed been reported in various environmental compartments from Asia including humans and wildlife, but this issue has received less attention in birds. In this article, we reviewed the available literature on levels of legacy persistent organic pollutants (POPs) and various flame retardants (FRs) in Asian avifauna to analyze the existing pool of knowledge as well as to identify the gaps that should be addressed in future research. Furthermore, we discussed the variation in levels of organohalogens based on differences in regions, trophic level, dietary sources and migratory behaviors of species including distribution patterns in different tissues of birds. Although the mass of published literature is very low and even absent in many important regions of Asia, we deduced from the reported studies that levels of almost all classes of organohalogens (OHCs) including FRs were highest in East Asian countries such as Japan, China and South Korea, except for HCHs that were found at maximum levels in birds of South India. Concentrations (ng/g LW) of different OHCs in Asian birds ranged between <LOD (limit of detection) to 14,000,000 for polychlorinated biphenyls (PCBs), <LOD to 790,000 for dichlorodiphenyltrichloroethane (DDTs), <LOD to 12,000 for hexachlorobenzene (HCB), <LOD to 29,000 for hexachlorocyclohexanes (HCHs), <LOD to 47,000 for chlordanes (CHLs) and <LOD to 4600 for total cyclodienes. Further, ranges (ng/g LW) of 1.1 to 150,000 for Co-PCBs; <LOD to 27 for polychlorinated dibenzo-p-dioxins (PCDDs); <LOD to 45 for polychlorinated dibenzofurans (PCDFs) and 0.02 to 73 for PCDD/DFs have been reported in Asian aves. Among emerging FRs, levels of total polybrominated diphenyl ethers (PBDEs), total dechlorane plus (DPs) [syn and anti DPs] and hexabromocyclododecane (HBCDs) oscillated between <LOD to 134,000, <LOD to 3820 [<0.1-920 and <0.1-2900], and <LOD to 11,800 ng/g LW, respectively. Corresponding ranges of novel brominated flame retardants (nBFRs) such as decabromodiphenyl ethane (DBDPE) and 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE) were <LOD to 820 and <LOD to 89 ng/g LW. Other nBFRs such as tetrabromobisphenol-A (TBBPA) hexabromobenzene (HBB) and pentabromoethylbenzene (PBEB) in Asian avifauna have been reported in very few studies. Dependence of organohalogens on dietary sources and subsequent biomagnification in the food chain has been corroborated through δ(15)N and δ(13)C stable isotope proxies. In general, tissues with higher fat content accumulated more organohalogens and vice versa. Aspects such as maternal transfer of OHCs and temporal trends have rarely been discussed in reported literature from Asia. The mobility of birds, vicinity to sources and trans-boundary movement of pollutants were identified as key exposure routes and subsequent OHCs contamination in Asian birds. There is extreme scarcity of literature on organohalogen contamination in birds from Northern, South-eastern and west Asian countries where an industrial boom has been witnessed in the past few decades. Current scenarios suggest that levels of OHCs, particularly the FRs, are rising in birds of Asia and it would be wise to develop baseline information and to regulate the OHCs emission accordingly.

Concentrations and patterns of organochlorines (OCs) in various fish species from the Indus River, Pakistan: A human health risk assessment

The present study was conducted to reveal the concentrations and patterns of organochlorines [i.e., organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs)] in freshwater fish species collected from four ecologically important sites of the Indus River i.e., Taunsa (TAU), Rahim Yar Khan (RYK), Guddu (GUD) and Sukkur (SUK). In the fish muscle tissues, concentrations of 15 OCPs (∑15OCPs) and 29 PCBs (∑29PCBs) varied between 1.93-61.9 and 0.81-44.2 ng/g wet weight (ww), respectively. Overall, the rank order of OCs was DDTs>PCBs>hexachlorocyclohexanes (HCHs)>chlordanes (CHLs). The patterns of PCBs showed maximum contribution of tri-CBs (59%). Ratios of individual HCH and DDT analytes contributing to the summed values indicated both recent and past use of these chemicals in the region, depending upon fish species. To assess the associated health risks, carcinogenic and non-carcinogenic risks were calculated through hazard ratios (HRs). For carcinogenic risk, HR was >1 at both 50th and 95th percentile concentrations, suggesting that the daily exposure to OCPs and PCBs yields a lifetime cancer risk of 1 in a million. HR for non-cancerous risk was <1 at both the percentiles, signifying no adverse effect by OCs exposure in native population.

Tracking the fingerprints and combined TOC-black carbon mediated soil-air partitioning of polychlorinated naphthalenes (PCNs) in the Indus River Basin of Pakistan

This study reports the first investigation of polychlorinated naphthalenes (PCNs) in air and soil samples from ecologically important sites of the Indus River Basin, Pakistan. The concentrations of ∑39-PCNs in air and soil were found in a range between 1-1588 pg m(-3) and 0.02-23 ng g(-1) while the mean TEQ values were calculated to be 5.4E(-04) pg TEQ m(-3) and 1.6E(+01) pg TEQ g(-1), respectively. Spatially, air and soil PCN concentrations were found to be high at Rahim Yar Khan (agricultural region). Lower-medium chlorinated PCNs (sum of tri-, tetra- and penta-CNs) predominated in both air and soil, altogether constituting 87 and 86% of total PCNs in the two environmental matrices, respectively. According to the data, soil-air partitioning of PCNs was interpreted to be similarly controlled by the combined effect of black carbon and organic matter in the Indus River Basin, with no preferential implication of the recalcitrant organic form.

Nucleophilic reactivity and electrocatalytic reduction of halogenated organic compounds by nickel o-phenylenedioxamidate complexes

Nickel(ii)-ate complexes supported by o-phenylenebis(N-methyloxamide) reacted with alkyl halides to form new imidate tautomers which were characterized by X-ray crystallography and FT-IR spectroscopy, and used for electroreduction of chloroform.

Organohalogenated contaminants in sediments and bivalves from the Northern Arabian Gulf

Several classes of Organohalogenated contaminants (OHCs) were determined in sediments and bivalves collected from Kuwait coast. The levels and profile of polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs) and polybrominated diphenyl ethers (PBDEs) were compared in both sediments and bivalves. PCB-153 and -138 were the major contributors towards total OHCs followed by DDT and its metabolites (DDTs). The higher contribution of DDTs (~40%) and BDE-47 (~15%) in bivalves as compared to that in associated sediments indicated high biota-sediment accumulation factors (BSAF). Higher BSAF (values for heavier PCBs, DDTs and PBDEs) also indicated their high accumulation potential from sediment into associated biota at most of the studied locations. Overall, OHCs in sediments and bivalves measured in current study were lower than those reported in the literature worldwide. Most of the sediment concentrations of OHCs (ng/g, dry weight) were in the range of permissible guideline values proposed by Canadian Sediment Quality Guidelines (CSQGs), with few exceptions for DDTs (5 ng/g) and PCBs (22.7 ng/g). Similarly, 10% of bivalve samples contained high levels (ng/g, lipid weight) of PCBs (300) and DDTs (150) and were above the set safety benchmarks. This study establishes baseline for future monitoring programs.

Exposure to Endosulfan can result in male infertility due to testicular atrophy and reduced sperm count

Endosulfan (ES) is a widely used organochlorine pesticide and is speculated to be detrimental to human health. However, very little is known about mechanism of its genotoxicity. Using mouse model system, we show that exposure to ES affected physiology and cellular architecture of organs and tissues. Among all organs, damage to testes was extensive and it resulted in death of different testicular-cell populations. We find that the damage in testes resulted in qualitative and quantitative defects during spermatogenesis in a time-dependent manner, increasing epididymal reactive oxygen species levels, affecting sperm chromatin integrity. This further culminated in reduced number of epididymal sperms and actively motile sperms. Finally, we show that ES exposure affected fertility in male but not in female mice. Therefore, we demonstrate that ES exerts pathophysiological changes in mice, induces testicular atrophy, affects spermatogenesis, reduces quantity and vigour of epididymal sperm and leads to infertility in males.

Occurrence of organochlorine pesticides in the environmental matrices from King George Island, west Antarctica

Antarctica is considered as a final sink of many persistent organic pollutants (POPs). This work aims to investigate the levels, distributions and potential sources of organochlorine pesticides (OCPs) with HRGC/HRMS technique. Twenty-three OCPs were measured in various environmental matrices from King George Island, west Antarctica. The total concentrations (Σ23OCPs) were at quite low levels, ranging 93.6-1260 pg g(-1) dry weight (dw) in soil and sediment, 223-1053 pg g(-1) dw in moss and 373-812 pg g(-1) dw in lichen. Hexachlorobenzene (HCB), dichloro-diphenyl-trichloroethane (DDT) and its metabolites (especially p,p'-DDE) and hexachlorocyclohexanes (HCHs) were the main contaminants in all samples. Lower α-HCH/γ-HCH and higher p,p'-DDE/p,p'-DDT ratios compared with the technical products indicated long-range atmospheric transport (LRAT) of recent lindane and aged technical DDT. Significant dependence of many OCPs concentrations on total organic carbon (TOC) was observed. Apart from LRAT, local biotic activities could also contribute and influence the spatial distribution of the contaminants.

The organochlorine pesticides residues in the invasive ductal breast cancer patients

Investigation of organochlorine pesticides residues (important environmental contamination causing malignant transformation) in breast cancer patients is valuable to understanding their roles in breast cancer. 75 invasive ductal carcinoma (IDC) patients were enrolled with control of 79 benign breast diseases patients and control of 80 healthy women. Morning fasting blood specimens and adipose tissue specimens beside the primary lesion were detected with gas chromatograph. In blood specimens, both levels of β-HCH and PCTA were higher in IDC than those in both controls (both p<0.05), and increasingly higher among the three IDC degrees. In adipose tissue specimens, all levels of β-HCH, PCTA and pp'-DDE were higher in IDC than those in control (all p<0.05) and increasingly higher among three IDC degrees. The levels of β-HCH, PCTA in both blood specimens and adipose tissue specimens were higher in estrogen receptor (ER) positive IDC than those in ER negative IDC (all p<0.05). The higher level of organochlorine pesticides residues in blood and adipose tissue specimens of IDC infers its association with IDC, but the details remains to reveal, and this study may helpful in this field.

Genotoxicity assessments of alluvial soil irrigated with wastewater from a pesticide manufacturing industry

In this study, organochlorine pesticides (OCP) and heavy metals were analyzed from wastewater- and groundwater- irrigated soils (control samples) by gas chromatography (GC) and atomic absorption spectrophotometry (AAS), respectively. Gas chromatographic analysis revealed the presence of high concentration of pesticides in soil irrigated with wastewater (WWS). These concentrations were far above the maximum residue permissible limits indicating that alluvial soils have high binding capacity of OCP. AAS analyses revealed higher concentration of heavy metals in WWS as compared to groundwater (GWS). Also, the DNA repair (SOS)-defective Escherichia coli K-12 mutant assay and the bacteriophage lambda system were employed to estimate the genotoxicity of soils. Therefore, soil samples were extracted by hexane, acetonitrile, methanol, chloroform, and acetone. Both bioassays revealed that hexane-extracted soils from WWS were most genotoxic. A maximum survival of 15.2% and decline of colony-forming units (CFUs) was observed in polA mutants of DNA repair-defective E. coli K-12 strains when hexane was used as solvent. However, the damage of polA (-) mutants triggered by acetonitrile, methanol, chloroform, and acetone extracts was 80.0, 69.8, 65.0, and 60.7%, respectively. These results were also confirmed by the bacteriophage λ test system as hexane extracts of WWS exhibited a maximum decline of plaque-forming units for lexA mutants of E. coli K-12 pointing to an elevated genotoxic potential. The lowest survival was observed for lexA (12%) treated with hexane extracts while the percentage of survival was 25, 49.2, 55, and 78% with acetonitrile, methanol, chloroform, and acetone, respectively, after 6 h of treatment. Thus, our results suggest that agricultural soils irrigated with wastewater from pesticide industries have a notably high genotoxic potential.

Environmental exposure to organochlorine pesticides and deficits in cochlear status in children

The aim of this study was to examine the hypothesis that organochlorine pesticides (OCPs), hexachlorobenzene (HCB), β-hexachlorocyclohexane (β-HCH), and 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (p,p'-DDT) and its metabolite 1,1-dichloro-2,2-bis(4-chlorophenyl)ethylene (p,p'- DDE) are ototoxic to humans. A multivariate general linear model was designed, in which the statistical relation between blood serum concentrations of HCB, β-HCH, p,p'-DDT, or p,p'-DDE at different ages (at birth, 6, 16, and 45 months) and the distortion product otoacoustic emissions (DPOAEs) was treated as multivariate outcome variables. Polychlorinated biphenyl (PCB) congeners and OCPs were strongly correlated in serum of children from our cohort. To ascertain that the association between DPOAEs at a given frequency and concentration of a pesticide is not influenced by PCBs or other OCP also present in serum, we calculated benchmark concentrations (BMCs) relating DPOAEs to a serum pesticide alone and in presence of confounding PCB-153 or other OCPs. We found that BMCs relating DPOAEs to serum pesticides are not affected by confounders. DPOAE amplitudes were associated with serum OCPs at all investigated time intervals, however, in a positive way with prenatal exposure and in a negative way with all postnatal exposures. We observed tonotopicity in the association of pesticides with amplitude of DPOAEs as its strength was frequency dependent. We conclude that exposure to OCPs in infancy at environmental concentrations may be associated with hearing deficits.

Multiyear Measurements of Flame Retardants and Organochlorine Pesticides in Air in Canada's Western Sub-Arctic

Fourteen polybrominated diphenyl ethers (PBDEs), 14 non-BDE flame retardants (FRs), and 25 organochlorine pesticides (OCPs) were analyzed in air samples collected at Little Fox Lake (LFL) in Canada's Yukon Territory from August 2011 to December 2014. LFL is a long-term monitoring station operated under the Northern Contaminants Program (NCP) and one of only a few stations that contribute to the assessment of air pollution levels and pathways to the sub-Arctic region. BDE-47 was the most abundant congener among the 14 PBDEs, followed by BDE-99. Non-BDE FRs pentabromotoluene (PBT) and dechlorane plus (DP) were detected in all the samples. Dechlorane 602, 2,3-dibromopropyl-2,4,6-tribromophenyl ether (DPTE), hexabromobenzene (HBB), and 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EH-TBB) were also detected in >75% of all samples. PBDEs have shown a decreasing tendency as of 2013, which may reflect the phase-out of penta- and octa-BDE mixtures has led to significant decline in the atmosphere. The highest concentrations of OCPs were observed for hexachlorobenzene (HCB), with a median concentration of 61 pg/m(3), followed by α-hexachlorocyclohexane (α-HCH) and α-endosulfan. Potential source contribution function (PSCF) highlights Northern Canada, Pacific, and East Asia as potential sources in warm seasons; whereas in cold seasons, the chemicals mainly came from the Pacific Rim.

Assessing the combined influence of TOC and black carbon in soil-air partitioning of PBDEs and DPs from the Indus River Basin, Pakistan

Levels of polybrominated diphenyl ethers (PBDEs) and dechlorane plus (DPs) were investigated in the Indus River Basin from Pakistan. Concentrations of ∑PBDEs and ∑DPs were ranged between 0.05 and 2.38 and 0.002-0.53 ng g(-1) in the surface soils while 1.43-22.1 and 0.19-7.59 pg m(-3) in the passive air samples, respectively. Black carbon (fBC) and total organic carbon (fTOC) fractions were also measured and ranged between 0.73 and 1.75 and 0.04-0.2%, respectively. The statistical analysis revealed strong influence of fBC than fTOC on the distribution of PBDEs and DPs in the Indus River Basin soils. BDE's congener profile suggested the input of penta-bromodiphenylether (DE-71) commercial formulation in the study area. Soil-air partitioning of PBDEs were investigated by employing octanol-air partition coefficients (KOA) and black carbon-air partition coefficients (KBC-A). The results of both models suggested the combined influence of total organic carbon (absorption) and black carbon (adsorption) in the studied area.

The potential effects of phytoplankton on the occurrence of organochlorine pesticides (OCPs) and polycyclic aromatic hydrocarbons (PAHs) in water from Lake Taihu, China

Seasonal distribution of organochlorine pesticides (OCPs) and polycyclic aromatic hydrocarbons (PAHs) and their possible interactions with phytoplankton species in water from Lake Taihu were investigated. OCP concentrations ranged from 69.95 to 223.08 ng L(-1) in winter and from 80.95 to 376.03 ng L(-1) in summer, while PAHs ranged from 45.40 to 232.74 ng L(-1) in winter and 49.53 to 197.72 ng L(-1) in summer. Such physicochemical and biological parameters as the larger amounts of pollutants taken up by phytoplankton, the increased atmospheric wet deposition, the discharge of wastewater, and the resuspension of polluted sediments in summer time were responsible for the higher residues of both OCPs and PAHs than in winter. Canonical correspondence analysis (CCA) between phytoplankton biomass and micropollutants indicated high affinity of OCPs to Bacillariophyta and Cryptophyta and PAHs to Cyanophyta and Chlorophyta, documenting the ecological effects of phytoplankton on the biogeochemical processes of OCPs and PAHs and thus should be further investigated especially in hyper-eutrophic lakes.

Pesticide residues in vineyard soils from Spain: Spatial and temporal distributions

Spatial and temporal evaluations of seventeen pesticides and some of their degradation products were carried out in seventeen vineyard soils from La Rioja region (Spain). The soils were sampled in March, June and October 2012, and the pesticides were selected among those previously detected in surface and ground waters from the same area. All pesticides were detected in some of the soils in the three different areas of La Rioja at the different sampling times, with only the metalaxyl metabolite, CGA-62826, not being detected in any of the soils sampled in October. The highest concentrations were determined for the fungicides metalaxyl (11.5 μg kg(-1)) and triadimenol (26.1 μg kg(-1)), the herbicides fluometuron (174.6 μg kg(-1)) and terbuthylazine (403.3 μg kg(-1)), and the insecticide methoxyfenozide (4.61 μg kg(-1)). While the highest total concentration of pesticides was detected in March, the highest number of positive detections was recorded in June (46), as opposed to 26 and 19 in March and October, respectively. Significant differences were detected in the concentrations of herbicides in soils from the three areas in La Rioja, but this was not the case for the fungicides and the insecticides. The study revealed a more intensive use of herbicides in March, while the use of insecticides and fungicides probably depended on the specific needs of crops and/or the onset of diseases. The results are consistent with the residues found in waters in the region, and highlight the need to implement strategies for more efficient application of these compounds to avoid risk of water contamination.

Monitoring of persistent organic pollutants in seawater of the Pearl River Estuary with rapid on-site active SPME sampling technique

An on-site active solid-phase microextraction (SPME) sampling technique coupled with gas chromatography-mass spectrometry (GC-MS) for sampling and monitoring 16 polycyclic aromatic hydrocarbons (PAHs) and 8 organochlorine pesticides (OCPs) in seawater was developed. Laboratory experiments demonstrated that the sampling-rate calibration method was practical and could be used for the quantification of on-site sampling. The proposed method was employed for field tests which covered large amounts of water samples in the Pearl River Estuary in rainy and dry seasons. The on-site SPME sampling method can avoid the contamination of sample, the losses of analytes during sample transportation, as well as the usage of solvent and time-consuming sample preparation process. Results indicated that the technique with the designed device can address the requirement of modern environment water analysis. In addition, the sources, bioaccumulation and potential risk to human of the PAHs and OCPs in seawater of the Pearl River Estuary were discussed.

Current status of persistent organic pesticides residues in air, water, and soil, and their possible effect on neighboring countries: a comprehensive review of India

Though the use of pesticides has offered significant economic benefits by enhancing the production and yield of food and fibers and the prevention of vector-borne diseases, evidence suggests that their use has adversely affected the health of human populations and the environment. Pesticides have been widely distributed and their traces can be detected in all areas of the environment (air, water and soil). Despite the ban of DDT and HCH in India, they are still in use, both in domestic and agricultural settings. In this comprehensive review, we discuss the production and consumption of persistent organic pesticides, their maximum residual limit (MRL) and the presence of persistent organic pesticides in multicomponent environmental samples (air, water and soil) from India. In order to highlight the global distribution of persistent organic pesticides and their impact on neighboring countries and regions, the role of persistent organic pesticides in Indian region is reviewed. Based on a review of research papers and modeling simulations, it can be concluded that India is one of the major contributors of global persistent organic pesticide distribution. This review also considers the health impacts of persistent organic pesticides, the regulatory measures for persistent organic pesticides, and the status of India's commitment towards the elimination of persistent organic pesticides.

Monitoring Pesticide Residues in Surface and Ground Water in Hungary: Surveys in 1990–2015

Over 2000 surface, ground and raw drinking water samples have been analyzed in the frame of different monitoring projects in Hungary and watercourses in neighboring countries between 1990 and 2015. Effects of pesticide contamination on ecological farming and drinking water supply have been assessed. Main water pollutant ingredients of agricultural origin in Hungary are herbicides related to maize production. After EU pesticide re-registration, diazinon, atrazine, and trifluralin gradually disappeared as contaminants. High levels of water soluble pollutants (e.g., acetochlor) in surface water result in temporarily enhanced levels in raw drinking water as well. Extreme levels observed for herbicide residues were of agrochemical industrial origin.

Persistent organochlorine pesticides in internal organs of coypu, Myocastor coypus

A highly selective and sensitive method based on gas chromatography-tandem mass spectrometry (GC-MS/MS) to identify and quantify persistent organochlorine pesticides, (18 compounds including primary compounds and metabolites), in animal internal organs (kidneys, liver, and brain) has been developed. Tandem mass spectrometric conditions were individually optimized for each target compound in Multiple Reaction Monitoring (MRM) mode to obtain maximum sensitivity. Prior to instrumental analysis, a sample preparation method based on matrix solid phase dispersion (MSPD) followed by acidic digestion with sulfuric acid to reduce matrix co-extractives was employed. Analyses of real samples were carried out on coypus (Myocastor coypus) from the autumn slaughter of 19 animals. In the analyzed samples, three of the target compounds, namely DDE-pp' (DDT metabolite), HCB and lindane, were detected. Their concentration levels fell in the ranges of 0.003-0.007, 0.003-0.025, and 0.003-0.021 mg kg(-1) (0.005, 0.010, and 0.010 mg kg(-1) on average) in the case of DDE-pp', HCB and lindane, respectively. Although low quantities of organochlorine pesticides do not pose an immediate danger to consumers' health, they should be of public health concern considering long-term, low-dose exposure.

Characterization of zebrafish Abcc4 as an efflux transporter of organochlorine pesticides

DDT and lindane are highly toxic organochlorine pesticides and posing adverse effects on the environment and public health due to their frequent usage in developing countries. ABCC4/MRP4 is an organic anion transporter that mediates cellular efflux of a wide range of exogenous and endogenous compounds such as cyclic nucleotides and anti-cancer drugs; however, it remains unclear whether ABCC4 and its orthologs function in the detoxification of organochlorine pesticides. Here, we demonstrated the roles of zebrafish Abcc4 in cellular efflux of DDT and lindane. Zebrafish abcc4 was maternally expressed in the oocytes and its transcripts were detected in the lens, pancreas, gills, liver, intestine and bladder of developing embryos and in adult tissues examined. DDT and lindane were able to induce the expression of abcc4 gene and overexpression of Abcc4 significantly decreased the cytotoxicity and accumulation of DDT and lindane in LLC-PK1 cells and developing embryos. In contrast, overexpression of an Abcc4-G1188D mutant abolished its transporter function without effects on its substrate binding activity, and sensitized LLC-PK1 cells and developing embryos to toxic pesticides. Moreover, glutathione (GSH) was involved in the efflux of cellular pesticides and ATPase activity in developing embryos can be induced by DDT or lindane. Thus, zebrafish Abcc4 plays crucial roles in cellular efflux of organochlorine pesticides and can be used a potential molecular marker for the monitor of DDT and lindane contamination in the aquatic environment.

Pesticide residues in fruits and vegetables from Pakistan: a review of the occurrence and associated human health risks

The main objective of the review is to document, assess and analyze the results of the previously reported data on levels of different pesticides in selected fruits and vegetables from Pakistan. The findings of the previous studies clearly indicated that more than 50 % of the samples were contaminated with organophosphate, pyrethroids and organochlorine pesticides. Many studies reported that among fresh fruits and vegetables tomato, apple, melon, mango, grapes, and plum crossed the FAO/WHO permissible limits for these contaminants residual levels. The comparison of other regions showed that observed levels were found above maximum residue limits (MRLs) in 50 % of the samples but were in agreement with the studies from neighboring countries like China and Bangladesh. Higher hazard risk index (HRI) values were calculated for dieldrin, methamidophos, o,p'-DDT, diazinon and p,p'-DDT in apple, mango, banana, melon, potato and onion. The review also highlights that data on pesticide residues in foodstuff is scarce which should be overcome by further extending studies from different areas of Pakistan. In order to ascertain the provision of food suitable for human consumption, it is imperative to monitor pesticides in food commodities by the country's authorities and enforce guidelines based on permissible limits.

The legal framework to manage chemical pollution in India and the lesson from the Persistent Organic Pollutants (POPs)

India's rapid agro-economic growth has resulted into many environmental issues, especially related to chemical pollution. Environmental management and control of toxic chemicals have gained significant attention from policy makers, researchers, and enterprises in India. The present study reviews the policy and legal and non-regulatory schemes set in place in this country during the last decades to manage chemical risk and compares them with those in developed nations. India has a large and fragmented body of regulation to control and manage chemical pollution which appears to be ineffective in protecting environment and human health. The example of POPs contamination in India is proposed to support such a theory. Overlapping of jurisdictions and retrospectively approached environmental policy and risk management currently adopted in India are out of date and excluding Indian economy from the process of building and participating into new, environmentally-sustainable market spaces for chemical products. To address these issues, the introduction of a new integrated and scientifically-informed regulation and management scheme is recommended. Such scheme should acknowledge the principle of risk management rather than the current one based on risk acceptance. To this end, India should take advantage of the experience of recently introduced chemical management regulation in some developed nations.

Assessing the relationship and influence of black carbon on distribution status of organochlorines in the coastal sediments from Pakistan

Levels of total organic carbon (TOC) and black carbon (BC) were determined together with those of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in the selected eighteen coastal sites (n = 285) along the Arabian Sea from Pakistan. Results showed that the total concentration of TOC, BC, ∑OCPs and ∑26PCBs ranged between 0.3 and 2.9% dw, 0.1-0.2% dw, 0.9-110 ng g(-1) dw and 6.2-1200 ng g(-1) dw, respectively. Correlation analysis of BC (r = 0.26-0.89) and TOC (r = 0.06-0.69) revealed a stronger association with studied compounds. The sedimentary depositional fluxes (D) for ∑OCPs and ∑26PCBs were calculated as 1.7 and 4.9 tons yr(-1), respectively. In the coastal belt of Pakistan, sedimentary mass inventories (I) indicated the presence of 13 and 37 metric tons of ∑OCPs and ∑26PCBs, respectively.

Organo-halogenated contaminants (OHCs) in the sediments from the Soan River, Pakistan: OHCs(adsorbed TOC) burial flux, status and risk assessment

In this study, regression analysis revealed that TOC is the principal factor in controlling the fate of organo-halogenated contaminants (OHCs: PCBs, PBDEs, OCPs) in Soan River, Pakistan. The OHCs(adsorbed TOC) burial flux (OHCs(adsorbed TOC)Bf; mg/cm(2)·yr) was calculated in the following ranges: ∑PCBs (0.07-0.31), ∑PBDEs (0.005-0.029), ∑HCHs (0.015-0.046) and ∑DDTs (0.007-0.039). Apart from OHCs(adsorbed TOC)Bf, the levels of OHCs were in the following order: PCBs>DDTs>PBDEs>HCH>Chlordane>HCB. PBDEs and PCB congener patterns showed following order respectively: BDE-149>-153>-18>-138>-44 and PCB-149>-153>-18>-138>-44. DDT isomers and metabolites' pattern were p,p'-DDT>p,p'-DDD>p,p'-DDE>o,p'-DDT>o,p'-DDD>o,p'-DDE and HCHs were β-HCH>α-HCH>γ-HCH>δ-HCH. PBDE composition had similarities to penta-BDE and DE-71 mixtures and PCBs with commercial products Aroclor-1254 and -1260. (DDE+DDD)/∑DDTs and p,p'-DDT/p,p'-DDE suggested the recent input of DDTs in sediments while α/γ-HCH indicated past usage of lindane and technical mixtures. Risk assessment suggested that Soan River and its tributaries are potentially at risk against most of the OHCs.

Biodegradation and utilization of organophosphorus pesticide malathion by Cyanobacteria

Three strains of filamentous Cyanobacteria were used to study their growth and utilization of organophosphorus pesticide malathion. A sharp decrease in the growth of the algal strains was observed by increasing the concentration of malathion. Amongst them Nostoc muscorum tolerated different concentrations and was recorded as the highest efficient strain for biodegradation (91%) of this compound. Moreover, carbohydrate and protein content of their cells overtopped the other strains especially at higher concentrations. The algal strains were further subjected to grow under P-limitation in absence and presence of malathion. Although, the algal growth under P-limitation recorded a very poor level, a massive enhanced growth and phosphorous content of cells were obtained when the P-limited medium was amended with malathion. This study clarified that N. muscorum with its capability to utilize malathion as a sole phosphorous source is considered as an inexpensive and efficient biotechnology for remediation of organophosphorus pesticide from contaminated wastewater.