Sources Of Organochlorine Pesticides Research Articles

Assessing the effect of COVID 19 lockdowns on the composition of organic compounds and potential source of PM2.5 in Hanoi, Vietnam.

The ambient air quality during COVID-19 lockdowns has been improved in many cities in the world. This study is to assess the changes in persistent organic pollutants in PM2.5 during the COVID-19 lockdown in Hanoi. Individual organic species in PM2.5 ((e.g., polycyclic aromatic hydrocarbons (PAHs), polychlorobiphenyls (PCBs), and organochlorine pesticides (OCPs)) were measured in an urban residential area in Hanoi from before the March 10th to April 22nd, 2020, including before the partial lockdown (BL) and the partial lockdown (PL) phases. During the PL phase, the concentration of Σ14PAHs and Σ28PCBs was reduced by 38 and 52% compared with the BL period, respectively. The diagnostic ratio method implied that the sources of PAHs within the PL phase had a less effect on traffic and industrial activities than in the BL phase. The characteristic ratio method indicated that PCBs were mixed by commercial product and combustion process in both the BL and the PL periods, however, the source of PCBs in the BL phase was influenced by municipal waste incineration more than those in the PL phase. The decreasing concentration of Σ20OCPs during the partial lockdown was attributed to the restriction of human activities during the quarantine period. The results suggested that the source of OCPs was probably derived from the usage of pesticides in current and, historical degradation or the transportation of pesticides from the soil to the atmosphere.

Organochlorine pesticide contamination of soils and dust from an urban environment in the Niger Delta of Nigeria

The concentrations, sources, and risk of twenty organochlorine pesticides (OCPs) in soils and dusts from a typical urban setting in the Niger Delta of Nigeria were examined. The Σ20 OCP concentrations (ng g−1) varied from 4.49 to 150 with an average value of 32.6 for soil, 4.67 to 21.5 with an average of 11.7 for indoor dust, and 1.6 to 96.7 with an average value of 23.5 for outdoor dust. The Σ20 OCP concentrations in these media were in the order: soil > outdoor dust > indoor dust, which was in contrast with the order of the detection frequency, i.e., indoor dust (95 to 100 %) > soil (60 to 90 %) > outdoor dust (30 to 80 %). The concentrations of the different OCP classes in these media followed the order: aldrin + dieldrin + endrin and its isomers (Drins) > chlordanes > dichlorodiphenyltrichloroethane (DDTs) > hexachlorocyclohexane (HCHs) > endosulfans for outdoor dust and soil, while that of the indoor dust followed the order: Drins > chlordanes > endosulfans > DDTs > HCHs. The cancer risk values for human exposure to OCPs in these sites exceeded 10−6 which indicates possible carcinogenic risks. The sources of OCPs in these media reflected both past use and recent inputs.

Distribution, Associated Risks and Sources of Organochlorine Pesticides in Farmland Soils from Ethiope West Area of Delta State, Nigeria

rganochlorine pesticides (OCPs) usage provides many advantages for agriculture; however, there are also significant concerns to the environment and public health. Since there is little information available on OCPs' distribution, associated risks and sources in Nigerian farmland soils, this study was carried out. Soil samples were collected from farmlands in ten communities. Samples were extracted with hexane/dichloromethane and cleaned up in a column of silica gel and florisil. The OCPs were measured using a gas chromatograph-mass spectrometry (GC-MS). The ∑20 OCPs levels in the soils varied between 47.5 and 109 ng/g. The OCPs homologues distribution in the soils was in the order of ∑DDTs > ∑Drins > ∑Chlordane > ∑BHCs > ∑Endosulfan. The risks assessment result indicated that there was adverse ecological effect on organisms residing in the soils and there is the likelihood that this effect will be frequently observed. Moreover, there was potential non-carcinogenic and carcinogenic risks for persons exposed to OCPs in these farmland soils. The result of the source identification indicated that historical usage was the main source of OCPs in these farmland soils. Keywords: Soil, Farmland, OCPs, Non-carcinogenic, Carcinogenic, Ethiope West

ORGANOCHLORINE PESTICIDES POLLUTION OF THE BOTTOM SEDIMENTS OF NAKHODKA BAY AND PARTIZANSKAYA RIVER

Link for citation: Mazlova E.A., Blinovskaya Ya.Yu., Sokolova L.I., Tursunova G.Sh. Organochlorine pesticides pollution of the bottom sediments of Nakhodka bay and Partizanskaya river. Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 9, рр. 25-35. In Rus. Relevance. The new data on the organochlorine pesticides pollution of the bottom sediments of Nakhodka bay and Partizanskaya river were obtained in 2020–2021. The objective of the article is to report the organochlorine pesticides pollution level of the bottom sediments and to define the possible sources of organochlorine pesticides in the marine environment. Techniques: sample collection of bottom sediments, Gas Chromatography Mass Spectrometry analysis of samples, Gas-liquid Chromatography method with electronic capture detector, statistical processing, assessment of the organochlorine pesticides contamination of sediments. Results. The new data were obtained on the organochlorine pesticides concentrations in Nakhodka bay in 2020–2021. The previous data on the studied area are described. The concentration of HCH pesticides (α- , β- and γ-HCH), DDT and its metabolites was analyzed. It was found that the concentration of α- , β- HCCH and DDT in bottom sediments increased in 2021.To determine the quality of bottom sediments, the average annual values of organochlorine pesticides concentrations in the bottom sediments gathered during the field works were compared with the quality guidelines. There are no approved quality guidelines for maximum permissible concentrations of pollutants in bottom sediments in the Russian Federation. For this reason, we used the quality guidelines applied in foreign countries («Dutch sheets» (Neue Niederlandische Liste. NNL) and Canadian quality standards for marine and estuarine bottom sediments (Canadian Sediment Quality Guidelines, CSQGs). Possible sources of organochlorine pesticides in the marine environment were analyzed. The results of this work showed that despite the ban on the use of these substances, these pesticides are included in the multiple compounds used in different industries and continue to enter and accumulate in the marine environment.

Spatial-temporal occurrence and sources of organochlorine pesticides in the sediments of the largest deep lake (Lake Fuxian) in China.

Compared with shallow lakes, less attention has been paid on pollutions in deep lakes. Lake Fuxian is the largest deep lake and an important water resource in China. The knowledge on organochlorine pesticides (OCPs) in sediments of Lake Fuxian was rare. Fifteen surface sediments and one sediment core were collected from Lake Fuxian. Sediment chronology was dated with the activities of 137Cs and 210Pb. Twenty-one OCPs in the surface sediments and sediment core were analyzed by a GC-MS. Spatial and temporal occurrences of OCPs in the sediments of this lake were studied. Correlations, isomer ratios, and principal component analysis (PCA) were applied to apportion the sources of OCPs in the sediments of this lake. The OCPs in the sediments of Lake Fuxian were dominated by p,p'-DDT (4,4'-dichlorodiphenyltrichloroethane) and HCHs (hexachlorocyclohexane). The concentration of ΣOCPs in the surface sediments ranged from 0.42 to 67.5ngg-1, with an average of 42.3 ± 23.5ngg-1 (mean ± SD, n = 15). The concentration of ΣOCPs in the sediment core varied from 3.5 to 707.9ngg-1 in the period from 1950 to 2010, with an average of 167.7 ± 203.7ngg-1 (n = 24). The highest concentrations and fluxes of α-HCH, γ-HCH, and p,p'-DDT were found in the years of 1964 and 1967, respectively. The fluxes of HCH isomers in the sediment core decreased in the orders as γ-HCH > β-HCH > α-HCH in the period from 1950 to 2010. The concentrations of HCHs and p,p'-DDT in the sediments of Lake Fuxian were higher than those of most shallow and deep lakes in the world. HCHs and p,p'-DDT were derived from both the technical HCH and DDT and the usage of lindane and dicofol. Technical DDT and technical HCH may be used simultaneously, but technical DDT and lindane were not applied simultaneously in the catchment. Lindane was used not only in the period from 2002 to 2010 but also in the period from 1950 to 1964 in the catchment.

Vertical distribution and effect of historical residual organochlorine pesticides on microbial community structure in sediment cores from an abandoned oxidation pond after dredging for 15 years.

The vertical distribution pattern of 19 organochlorine pesticides (OCPs), together with microbial ester-linked fatty acid methyl ester (EL-FAME) profiles were investigated in sediments from an abandoned oxidation pond of Ya-Er lake, China, which had been heavily polluted by hexachlorocyclohexanes (HCHs) and chlorobenzenes in 1980s. Subsurface sediment samples were taken from five sediment cores along the transect running from the lakeshore (0.5~2.7 m in depth) to lakebed (0.1~0.4 m). The total OCP concentration ranged from 29.8 to 941.8 ng g-1 dw. Hexachlorobenzene (HCB), HCHs, and dichlorodiphenyl-trichloroethanes (DDTs) were the three dominant OCP classes, accounting for 26.5-97.4%, 1.8-33.2%, and 0.4-15.5% of the total OCP concentration, respectively. Hot spots of HCB, HCHs, and DDTs were detected at 0.9~2.7 m deep layers of the lakeshore, where was oncethe maindredged sediment backfill site for in-situ remediation of the oxidation pond in 2002-2004. HCHs and HCBstill showed high potential ecological risks. The sources of OCPs were identified and quantified using principal component analysis with absolute principal component scores-multiple linear regression model. The firstthree major sources were persistent residues, recent agricultural input, and historical industrial input, contributing on average 28.2%, 17.9%, and 17.1% of total OCPs, respectively. Redundancy analysis of microbial EL-FAME profiles and nine dominant OCPs revealed that the spatial variation in microbial community structure was significantly corresponded with the OCP composition. This is the first study highlighting the concern on historical industrial inputs of OCPs in subsurface sediments of the lakeshore disposal zone. The findings could help to distinguish the artificial backfill sediments from undisturbed polluted sediments for optimization of further dredging plans.

Residual Characteristics and Health Assessment Analysis of OCPs and PCBs in Karst Groundwater

Residual levels of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in karst groundwater in Nanshan Laolongdong were measured using a gas chromatograph equipped with a micro-63Ni electron capture detector to determine the residual characteristics including concentration, distribution, and source of OCPs and PCBs. Results revealed that the total concentration range of OCPs was 34.8-623.2 ng·L-1, and the mean value was 215.6 ng·L-1, among which the total concentration ranges of HCHs, DDTs, and other OCPs were 8.2-23.6, 4.5-363.7, and 22.2-235.9 ng·L-1, respectively, and the mean values were 15.9, 104.5, and 95.3 ng·L-1; the total concentration range of PCBs was 6.0-40.7 ng·L-1, and the mean value was 16.8 ng·L-1. Overall, the pollution of OCPs and PCBs was above average; the results of multiple comparisons revealed that statistically significant differences occurred in the concentration of some OCPs and PCBs. The pollution levels in the water of each sampling point in the study area were quite different; however, the seasonal distribution of OCPs and PCBs was relatively uniform. Source analyses revealed that HCHs' source was the input of lindane in the surrounding environment, DDTs recently originated from illegal use of industrial DDT, other OCPs originated from atmospheric deposition and agricultural input, and PCBs' sources included both historical remains and enterprise production processes. The results of Pearson correlation analyses revealed that some organo-halogen pollutants were homologous or had similar sources and decomposition mechanisms. According to health risk assessment model, drinking water in the study area would not cause obvious harm to human health, but children were more sensitive to pollutants than adults.

Spatial distribution and sources of organochlorine pesticides in surface waters of Shanghai, China

The concentrations, distribution, influencing factors, and sources of 26 organochlorine pesticides (OCPs) were investigated in surface waters of Shanghai. Surface waters in this study refer to the freshwater that contains particles smaller than 0.45 μm in size. Total concentrations of OCPs ranged from 5.90 to 158.16 ng/L with a mean value of 78.11 ng/L. The OCP concentrations were generally low, but with a few relatively high concentrations at sites in the northern and southern regions of Shanghai. Dissolved oxygen, electrical conductivity, pH and oxidation–reduction potential had an important impact on the distribution of OCPs, which showed a significant negative correlation (p HCHs > Endosufan and Methoxychlor > Propachlor > Heptachlor and DDTs > Dacthal and Chlordane. The contribution of historic residual HCHs in Shanghai’s surface waters was not significantly different from that of atmospheric deposition, and a part of HCB was likely from the degradation of HCHs. DDTs were mainly from historical residues, although some were derived from recent inputs, and the main sources of heptachlors were also the historical residues. However, the recent input and historical residues of aldrins were both noticeable. The fluctuation of OCPs pollution levels and source differences among different intensive land-use types were relatively insignificant (p > 0.05).

Sources, distribution, and risk assessment of organochlorine pesticides in Nairobi City, Kenya

The distribution and sources of organochlorine pesticides (OCPs) in air and surface waters were monitored in Nairobi City using triolein-filled semipermeable membrane devices (SPMDs). The SPMDs were extracted by dialysis using n-hexane, followed by cleanup by adsorption chromatography on silica gel cartridges. Sample analysis was done by GC-ECD and confirmed by GC–MS. Separation of means was achieved by analysis of variance, followed by pair-wise comparison using the t-test (p≤ 0.05). The total OCPs ranged between 0.018 – 1.277 ng/m3 in the air and <LOD – 1391.000 ng/m3 in surface waters. Based on the results, the means of Industrial Area, Dandora and Kibera were not significantly different (p≤ 0.05), but were higher (p≤ 0.05) than those of City square and Ngong’ Forest. The results revealed non-significant (p≤ 0.05) contribution of long-range transport to OCP pollution in Nairobi City. This indicated possible presence of point sources of environmental OCPs in the city. The water-air fugacity ratios indicated that volatilization and deposition played an important role in the spatial distribution of OCPs in Nairobi City. This indicated that contaminated surface waters could be major sources of human exposure to OCPs, through volatilization. The incremental lifetime cancer risks (ILCR) determined from inhalation of atmospheric OCPs were 2.3745 × 10−13 – 1.6845 × 10−11 (adult) and 5.5404 × 10−13 – 3.9306 × 10−11 (child) in the order: Dandora > Kibera > Industrial Area > City Square > Ngong’ Forest. However, these were lower than the USEPA acceptable risks, 10−6 – 10−4. This study concluded that atmospheric OCPs did not pose significant cancer risks to the residents.

Sedimentary records of historical occurrence and sources of 21 organochlorine pesticides in Lake Taihu, China

PURPOSE: Sediments are natural archives to record the occurrence and sources of organochlorine pesticides (OCPs). Most previous studies on historical occurrence and sources of OCPs in China only focused on DDTs and HCHs. Comprehensive knowledge of historical occurrence and sources of persistent OCPs in China are scarce. MATERIALS AND METHODS: One 20-cm sediment core was collected from the third largest freshwater lake (Lake Taihu) in China, then sliced every 1 cm, dated with ¹³⁷Cs and ²¹⁰Pb, and used for the analysis of 21 OCPs. Isomer ratios and principal component analysis (PCA) were applied to apportion the historical sources of the OCPs in this lake. RESULTS AND DISCUSSION: Three concentration peaks of OCPs were observed in the middle-late 1950s, early-middle 1980s, and the middle 2000s. The average concentration of ΣDDX was 238.55 ± 55.43 ng gdw⁻¹ from 1948 to 2012. p,p′-DDT was the dominant congener of DDX, mostly derived from the legacy technical DDT. The average concentration of ΣHCHs, aldrin, heptachlor epoxide, endosulfan sulfate, methoxychlor, heptachlor, trans-chlordane, cis-chlordane, endosulfan I, endrin, diendrin, endosulfan II, diendrin aldehydrate, and diendrin ketone were 24.56 ± 6.90, 10.35 ± 3.26, 9.51 ± 1.88, 7.37 ± 1.81, 7.01 ± 2.82, 2.60 ± 0.81, 0.63 ± 0.24, 3.21 ± 1.25, 1.04 ± 0.29, 3.89 ± 2.61, 5.67 ± 1.59, 1.07 ± 0.19, 1.09 ± 0.22, and 1.32 ± 0.33 ng gdw⁻¹. CONCLUSIONS: Dicofol and p,p′-DDT-containing anti-fouling paints may be responsible for the current input of p,p′-DDT. Most of the HCHs were derived from the legacy technical HCHs, but there was input of lindane as well. PCA indicated that the legacy technical DDTs, HCHs, heptachlor, chlordane, aldrin, and endrin, the current input of p,p′-DDT, methoxychlor, and endosulfan, and microbial transform of γ-HCH to α-HCH were the dominant sources for the 21 OCPs in Lake Taihu.

Levels, Potential Sources and Risk Assessment of Organochlorine Pesticides in Atmospheric Particulate Matter at Regional Background Site

ABSTRACT Forty-eight PM2.5 samples were collected from June to August 2015 at the summit of Mount Tai. The samples were analyzed to determine the concentrations, potential sources and health risk of organochlorine pesticides (OCPs). Total OCPs concentration in PM2.5 ranged from 20.5 to 331 pg m–3. Hexachlorocyclohexane (HCHs) were the most abundant compounds. The sources of OCPs used potential source contribution function (PSCF), back trajectory analysis and principal component analysis suggested that the southwest agricultural areas and southeast regions of Mount Tai were the significant contributions regions of OCPs. Both old residual and new input were considered to the contribution of OCPs contamination. Human health risk assessment was carried out by non-carcinogenic health hazard quotient (HQ). The HQ values through inhalation and dermal contact ranged from 9.28 × 10–12 to 6.56 × 10–3, indicating a negligible risk of the study area.

Characteristics of Organochlorine Pesticides (OCPs) in Soil Samples of Hanjiang River Basin, Southeast China

Seventeen soil samples were collected along the main stream of the Hanjiang River in April 2013. Thirteen types of organochlorine pesticides (OCPs) were detected in the samples by gas chromatography with a 63Ni electron capture detector. The purpose of this study was to investigate the distribution, composition, and source of OCPs and assess the potential health risks for local residents. The 13 types of OCPs were all detected in this region, ranging from 2.97 ng·g-1 to 1275.79 ng·g-1, and the detection rates were 75%-100%. The contribution trends of both hexachlorocyclohexanes (HCHs) and dichlorodiphenyltrichloroethanes (DDTs) were upstream < midstream < downstream. Based on the ratio method, the HCHs were mainly from technical HCH input. Furthermore, there was DDT input recently, which contained industrial DDT and dicofol. The DDTs concentrations significantly correlated with total organic carbon. The values of cancer and non-cancer risks (10-12-10-8 and 10-6-10-3) were both lower than the corresponding thresholds (10-6 and 1), which indicated that the soils in the Hanjiang River Basin had no harmful effects on local residents.

Occurrence and possible sources of organochlorine pesticides in soils of Ningbo, East China

ABSTRACTStudy of the residues of organochlorine pesticides (OCPs) can assist with the assessment of the contamination level, distribution, sources, transportation and trends in these selected OCPs. We investigated the concentration levels of hexachlorocyclohexanes (HCHs), dichlorodiphenyltrichloroethane (DDT), chlordane, which is currently used, and the never-used aldrin and dieldrin in the Ningbo region – a heavily industrialised and urbanised area in East China. OCPs were found in all soil samples and were predominantly composed of HCHs, DDT and its metabolites. The concentration of DDTs in the soil ranged from 2.2 to 566.6ngg–1, with a mean value of 55.6±94.8ngg–1, while the concentration of HCHs ranged from 2.7 to 28.2ngg–1, with an average of 4.6±2.9ngg–1. Aldrin, dieldrin, endrin and heptachlor were detected at much lower concentrations. The wide distribution of these never-used OCPs indicates that they have been input via long-range atmospheric processes. The results from analysis suggest that HCHs and DDTs were mainly derived from use in historical times.

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, 0.05-60.05ng/g) and dichloro-diphenyl-trichloroethane (DDTs, 0.06-35.79ng/g) in the study areas compared with Wolong Nature Reserve (0.03-0.81ng/g for HCHs and 0.02-0.40ng/g for DDTs). The concentrations of most OCPs in soil of Beichuan County (e.g., 0.10-60.05ng/g for HCHs and 0.17-35.79ng/g for DDTs) were much higher than those of Dujiangyan City (e.g., 0.05-20.58ng/g for HCHs and 0.06-10.69ng/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.

Organochlorine pesticides in protected areas: El Hito Lake (Cuenca, Central Spain)

El Hito Lake is an ephemeral saline water mass present most of the year as a gypsiferous salt pan that is temporarily flooded during rainy periods, when it becomes a refuge for migratory birds such as flamingos and cranes, among others. It is considered an important hotspot of biodiversity and as such is covered by protection status. In order to check the environmental condition of the lake and determine the spatial distribution and source of organochlorine pesticides (OCPs), we performed a detailed soil and sediment sampling campaign with the catchment and dry lake bottom. We present the first environmental evaluation of its current state with respect to OCPs: hexachlorobenzene (HCB), hexachlorocyclohexanes (α-, β-, γ- and δ-HCH), dichlorodiphenyltrichloroethane (DDT) and its metabolites (DDE and DDD), and cyclodienes (aldrin, dieldrin, endrin, endrin aldehyde, endrin ketone, α-chlordane, γ-chlordane, endosulfan I, endosulfanII, endosulfan sulphate, heptachlor, heptachlor epoxide B and metoxichlor). Some of the compounds showed concentrations above the soil screening levels (SSLs) for human health and ecosystems: γ-HCH (100 μg/kg), α-HCH (60 μg/kg), endrin (30 μg/kg), aldrin (30 μg/kg) and heptachlor epoxide B (30 μg/kg). Various indices were used to determine the origin of the compounds. Historical uses were interpreted, although there were traces of recent input. Distribution maps of concentration and indices demonstrate a relationship between farming and cropping and the maxima observed, being possible that OCPs have influence in living beings, especially birds.

Distribution and source of organochlorine pesticides (OCPs) in the sediments of Poyang Lake

The concentrations of typical organochlorine pesticides (OCPs) (DDTs, HCHs, PCP-Na, and HCB) were measured to understand distribution and source of OCPs in surface and columnar sediments of Poyang Lake in 2006. And OCPS concentrations in surface sediment in 2017 were made a comparison with those in 2006 at several same sampling sites. OCPs showed higher concentrations in main stream than in river mouths (entrance of river flow into lake) of the lake. The average concentrations of HCHs and DDTs were 4.63 ± 3.86 and 20.15 ± 26.86 ng/g in surface sediments in 2006, respectively. Concentrations of OCPs in 2017 were lower than in 2006, such as HCHs average 1.98 ± 2.04 ng/g and DDTs average 4.87 ± 1.48 ng/g in 2017, indicating historical residual and degradation. The primary isomers of HCHs and DDTs in the lake were α-HCH, γ-HCH and p,p′-DDD, respectively. HCHs were from historical residual and lindane application. DDTs were from historical residual. PCP-Na total concentrations in surface sediment were 77.36 ng/g in 2006 and 44.04 ng/g in 2017. The concentration of HCB residues in surface sediment was 0.92 ± 0.90 ng/g in 2006 and 0.42 ± 0.38 ng/g in 2017. The concentrations of OCPs in columnar sediments showed annual variations, and the peak concentrations occurred in 1953, 1961, 1974, 1982, and 1995, showing close relations with onset of production OCPs pesticide in 1950s and its later prohibition in 1980s and a large number agricultural cultivated land decrease in 1990s in China. The concentrations of HCB in columnar sediments were average 2.33 ± 1.26 ng/g. OCPs of columnar sediments were from historical residues and lindane input. The main contamination of OCPs was PCP-Na and p,p′-DDD in Poyang Lake. On the whole, the combination of surface samples (0–5 cm in depth) and columnar samples (0–38 cm in depth) in a single study would give insight into OCPs pollution levels in different years (temporal resolution) and in different regions (spatial resolution) in Poyang Lake.

Occurrence, distribution and possible sources of organochlorine pesticides in peri-urban vegetable soils of Changchun, Northeast China

ABSTRACTThe characterizations of residue levels and sources of organochlorine pesticides (OCPs) in soils are necessary to evaluate the potential pollution and risks of OCPs to the ecosystems and human health. A total of 51 surface soil samples were collected from peri-urban vegetable fields of Changchun and 13 OCPs were analyzed to learn the composition, spatial distribution and sources. The concentrations were in the ranges of 0.94–107.8 ng g−1 for DDTs, 0.89–98.3 ng g−1 for HCHs, 0.22–18.20 ng g−1 for Chlordanes, nd–4.49 ng g−1 for aldrin and nd–9.66 ng g−1 for dieldrin, respectively. The total OCPs concentrations ranged from 2.44 to 177.1 ng g−1 and the higher residues were mainly distributed in northeast and southwest sites, as well as sites along the Yitong River. According to the concentrations and detection frequencies, DDTs and HCHs were the most dominant compounds. Compositional analysis and principal component analysis suggested that DDT, HCH and chlordane in most soil samples derived from historical application except the slight fresh introduction at some locations. There exist a variety of OCPs residues in peri-urban vegetable soils of Changchun, but it is still safe and suitable for agricultural production for the most part, and some specific locations with high OCPs residues ought to be a cause for concern.

Bioindicators of Organochlorine Pesticides in the Sea of Okhotsk and the Western Bering Sea.

Organochlorine pesticides (OCPs), such as HCHs and DDTs, are still used as pesticides in the Southern Hemisphere and can reach the North Pacific due to long range atmospheric transfer. Marine mammals (Pacific walrus Odobenus rosmarus divergens, gray whale Eschrichtius robustus), the seabirds (Pacific gull Larus schistisagus, crested auklet Aethia cristatella, auklet crumb Aethia pusilla, northern fulmar Fulmarus glacialis, and grey petrel Oceanodroma furcata) and Pacific salmon (pink Oncorhynchus gorbuscha, chum O. keta, chinook O. tshawytscha, and sockeye O. nerka) were collected near the Kuril Islands (the northern-western part of the Pacific Ocean), in the Sea of Okhotsk and the Bering Sea. The total OCPs concentration (HCHs+DDTs) was found in each organism, including the Pacific walrus (70-90,263ng/g lipid), the seabirds (29-16,095ng/g lipid), and the Pacific salmon (41-7103ng/g lipid). The concentrations and possible sources of OCPs in marine organisms as biological indicators are discussed.

Levels and Sources of Organochlorine Pesticides in Surface Sediment from Anhui Reach of Huaihe River, China.

Twenty-two organochlorine pesticides (OCPs) were investigated in Anhui reach of Huaihe river, China. Seventeen out of 22 OCPs were detected by GC-MS. The mean concentrations of OCPs followed the order: HCHs > DDTs > HCB > chlordanes > endosulfans. Levels of total HCHs and total DDTs ranged from 2.54 to 13.91ng g-1 (mean = 7.52ng g-1) and 0.016 to 2.54ng g-1 (mean = 0.45ng g-1), respectively. The concentrations of DDTs were lower than those of HCHs. Compared with the other rivers in China, DDTs and HCHs were relatively lower or similar. Statistical analysis indicated that the OCPs concentration differences were not insignificant between upstream, midstream and downstream. The compound compositions suggested that historical usage of lindane and fresh DDT were the main sources. The regression analysis indicated that TOC has influence on the levels of HCHs and little influence on the levels of DDTs in the sediments.

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.