Residual Levels Of Organochlorine Pesticides Research Articles

Evaluating bottle liquid-liquid extraction technique for monitoring residual levels of organochlorine pesticides in wastewater treatment-associated matrices

The gold standard for recovering residual organochlorine pesticides from wastewater and aqueous environmental matrices is the continuous liquid-liquid extraction (CLLE) technique that requires methylene chloride (CH2Cl2) as solvent at its refluxing temperature. In light of a recent USEPA proposed prohibitions and workplace protections for CH2Cl2 (due to its toxicity) and the fact that CLLE requires expensive and hard-to-acquire glassware, an alternative to CLLE as currently practiced is needed. The bottle liquid-liquid extraction (BLLE) technique, demonstrated for extracting semi-volatile organic contaminants from surface water, is potentially a low cost and high throughput alternative for such recovery. BLLE is cheaper and has a smaller laboratory footprint. The technique, performed at ambient temperature in a tightly capped bottle, requires less amount of solvent and contains solvent vapor within the bottle. The latter means less CH2Cl2 is encountered in the workplace. In this study, BLLE was performed directly in 1-L amber sampling bottles and shown to recover 21 organochlorine pesticides as efficiently as CLLE from influents and effluents of two wastewater treatment plants Because no statistical differences were found between CLLE (mean = 77.4, SD = 9.28) and BLLE (mean = 79.1, SD = 14.3); t(22) = 0.548, p(same mean) = 0.58, even though CLLE recovered more pesticides than BLLE by 5.18 ± 8.15%, these techniques are amenable to interchangeable usage. The systematic bias so far detected fits the expression BLLE = 1.4[CLLE] – 35 (r = 0.88). Both CLLE and BLLE recoveries were consistently higher for 4,4′-DDD and lower for aldrin, heptachlor and endrin aldehyde. Diethyl ether addition, as some suggested, did not improve BLLE.Synopsis: There is need to find a cheap, reliable and high throughput technique for purifying SVOCs from aqueous environmental media efficiently. BLLE, a little known technique, fulfils this need.

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.

Residues of organochlorine pesticides and polycyclic aromatic hydrocarbons in surface waters, soils and sediments of the Kaidu River catchment, northwest China

We investigated residual levels of organochlorine pesticides (OCPs) and polycyclic aromatic hydrocarbons (PAHs) in water, soil and sediments from the Kaidu River catchment in Xinjiang, an arid zone in northwest China. Sediments from areas with highly polluted soil have higher OCPs and PAHs, caused by intensive anthropogenic activities. Pollution concentrations, however, were lower than those in Lake Bositeng indicating that the lake is a sink for pollutants in this region. Source analysis indicated that hexachlorocyclohexanes (HCHs) and dichlorodiphenyltrichloroethanes (DDTs) originated mainly from historical agricultural applications. DDTs in sediments of the Lake Bositeng Estuary, however, may contribute to pollutant resuspension, resulting from sediment disturbance, and recent inputs. Low-molecular-weight PAHs were predominant, indicating that PAHs originated primarily from low-temperature combustion processes and petroleum-derived sources. A risk assessment of OCPs and PAHs in soil and sediment, suggested that concentrations were not high enough to cause adverse biological effects in the aquatic ecosystem.

Concentration and Influence Factors of Organochlorine Pesticides in Atmospheric Particles in a Coastal Island in Fujian, Southeast China

Atmospheric particulate samples collected from Pingtan Island in Fujian province were analyzed for 20 organochlorine pesticides (OCPs) with the aims of elucidating the contamination levels and their influence factors, and providing more comprehensive and fundamental data for the risk assessment of OCPs in this coastal area. The concentration of total OCPs ranged from ND (not detected) to 27.25 pg m–3 (an average of 4.30 ± 4.07 pg m–3) and ND to 13.16 pg m–3 (an average of 3.11 ± 2.54 pg m–3) in 2006 and 2007 respectively, and the level are obviously lower than urban, industrial, suburban, and the similar research areas in the coastal areas of Europe. HCH (Hexachlorocyclohexane) and DDT (Dichlorodiphenyltrichloroethane) were the predominant contaminants, followed by Methoxychlor and Endrin, while the levels of Chlordane, Endosulfan, Aldrin and Dieldrin was relatively lower. Obvious seasonal variations in OCP levels correlate significantly with total particulate levels; higher concentrations of most OCP compounds appeared in winter, whereas lower concentrations appeared in summer. The distribution pattern of the level of most OCP compounds might be directly or indirectly influenced by meteorological conditions, and TOC (total organic carbon) is an important factor influencing the persistence of these OCPs in atmospheric particulates. The source of atmospheric particulates was traced by stable carbon isotopes, which indicate that the increased levels of OCPs in winter and spring influenced by the source of polluted air mass during the “heating season” of Northern China. The cancer risk probability was evaluated based on the residual levels of OCPs, and the results show that dermal contact was the primary pathway affecting human health, and the effect of OCP residuals in atmospheric particulates of the coastal area could not be neglected.

Characteristics of residual organochlorine pesticides in soils under different land-use types on a coastal plain of the Yellow River Delta.

The residual levels of organochlorine pesticides (OCPs) were examined in soils covering five types of land use along a salinity gradient on the Yellow River Delta. The most prominent OCPs were dichlorodiphenyltrichloroethane (∑DDT, arithmetic mean=5.11μgkg(-1)), hexachlorocyclohexane (∑HCH, 1.69μgkg(-1)) and ∑endosulfan (10.4μgkg(-1)). The spatial variability of OCPs composition shifted from γ-HCH and o,p'-DDT dominated pesticides in coastal soils to p,p'-DDE dominated pesticides in inland soils. In different land-use types, the percentages of β-HCH and p,p'-DDE are characterized by more recalcitrant components in decreasing order of vegetable fields, cereal fields, cotton fields, wetlands and tidal flats with increasing soil salinity. However, the less recalcitrant components, γ-HCH and o,p'-DDT, showed an opposite trend. Endosulfan sulfate predominated in all land-use types. Residual levels of β-HCH were affected by soil organic matter. The correlations between γ-HCH and clay content and between p,p'-DDE, o,p'-DDT and salinity might associate with the influence of sediment cotransport by the Yellow River and the density of anthropogenic activities in coastal region. Depth distribution of the OCPs in typical soil profiles also implied that local historical usage and sediment transport by the Yellow River both affected the OCPs residual in this region.

Residual Levels of Organochlorine Pesticides and Heavy Metals in the Guanzhong Region of the Weihe Basin, North-western China

The residual concentrations of 20 types of organochlorine pesticides (OCPs) is 0.33 to 130.34 ng·g–1 (dry mass) in typical soils from 67 orchards spread over six counties in the Guanzhong region of the Weihe Basin, north-western China. Meanwhile, the concentration range of valid state Cu, Zn, and Cd in soil is 0.13 to 1.81 mg·kg–1, ND to 3.96 mg·kg–1, and ND to 0.047 mg·kg–1, respectively. The average residual concentrations of OCPs present a class of multiple order distribution with both latitude and longitude. The residual concentrations of valid state Cu and Zn have some correlation with the residual concentrations of OCPs.

Risk assessment and influence factors of organochlorine pesticides (OCPs) in agricultural soils of the hill region: A case study from Ningde, southeast China

Surface soil samples from farmlands in Ningde were analyzed for 20 organochlorine pesticides (OCPs) with the aim of elucidating contamination profiles, distribution characteristics, influencing factors and carcinogenic risks of these compounds in this hilly region. The total concentrations of OCPs ranged from 3.66 to 658.42ng/g, with a mean of 78.83ng/g. HCHs, DDTs and Endosulfans were the predominant contaminants in agricultural soils. The residual levels of OCPs on vegetable farmlands were significantly higher than those of corresponding counterparts on paddy farmlands, mainly attributed to variations in pesticide application and OCP degradation in the soils. Potential source analysis traced the occurrence of high residual levels of DDTs and HCHs to historical applications. Spearman correlation analysis pointed to TOC as a significant variable controlling OCP distribution, and artificial influences possibly contributed to the fate of OCPs in the soils. The OCP contamination levels in the agricultural soils based on national standards are generally considered safe for crop production, but they however, pose significant carcinogenic risks to exposed populations based on the calculated results of the incremental lifetime cancer risk (ILCR) parameters.

Temporal and spatial variations of organochlorine pesticides in the suspended particulate matter from Lake Chaohu, China

The residual levels of organochlorine pesticides (OCPs) in the suspended particulate matter (SPM) from Lake Chaohu were measured. The temporal–spatial distributions, potential sources, water-SPM partition and ecological risks of OCPs were studied. Total 17 OCP components were detected with total contents of 172.68±434.88ng/g. The total DDT parent compounds and their metabolic products (DDXs), with a total average content of 138.76±407.27ng/g, was the predominant components. The compositions of OCPs, DDXs and HCHs in the SPM were very similar to those in the air particulate, especially in spring and summer. Temporally, the highest residual levels of DDXs, HCHs and OCPs were found in August, which is very similar to temporal distribution trends in the water. Spatially, the highest residual levels of DDXs and OCPs in the SPM were found in the eastern lake area, followed by the western and the central lake areas. There were significant positive relationships between the contents of OCPs and DDXs in the SPM and those in the water. All water-SPM partition coefficient (Kd) values of OCPs were higher than 1, except those for p,p′-DDE, p,p′-DDT, HCB and γ-chlordane. The ratios of o,p′-/p,p′-DDT and DDT/(DDD+DDE) for all detectable SPM samples were less and greater than 1.00, respectively, which might indicate the new inputs of industrial DDTs. The ratios of α-/γ-HCH and β-/(α+γ)-HCH were less than 4 and 0.5, respectively, for the most of detectable SPM samples, which might demonstrate the recent inputs of lindane. The DDT and DDX residues in some SPM samples exceeded their corresponding probable effect concentrations, which indicated their adverse effects on the aquatic organisms.

Distribution, source identification and risk assessment of organochlorine pesticides (OCPs) in suspended particulate matter (SPM) from Lake Chaohu

The residual levels of organochlorine pesticides( OCPs) in suspended particulate matter( SPM) of four sampling sites collected from Lake Chaohu( May 2010-April 2011) were measured. The temporal-spatial variation and composition of OCPs were analyzed and potential sources and ecological risks of OCPs were also explored. Results showed that:( 1) Seventeen types of OCPs were detected in the SPM samples of Lake Chaohu,including 4 isomers of HCHs( α-,β-,γ-,δ-HCH),two parent DDT compounds( o,p'-,p,p'-DDT) and their three metabolic products( o,p'-,p,p'-DDE,p,p'-DDD),HCB,Heptachlor,Aldrin,Isodrin,2 isomers of Chlordane( α-,γ-chlordane),Endosulfan I and Mirex.( 2) The annual average concentration of ∑OCPs in the SPM of Lake Chaohu was 172. 7 ± 434. 9 ng / g,and HCHs and DDTs accounted for 15. 1 ± 10. 3 and 138. 8 ± 407. 3 ng /g,respectively. The DDT content reached a maximum value in the summer. Regarding the spatial variability in the degree of pollution,the following trend was observed: eastern lake western lake central lake.( 3) DDTs were the primary constituents of the total OCPs. The proportion of DDTs was the highest in the summer and the lowest in the fall. However,HCHs were the most significant pollutants only in the fall.( 4) Considering possible sources,HCHs were derived from the illegal use of lindane,while DDTs likely originated from the industrial use of DDTs and illegal use in the spring. Moreover,DDTs degraded primarily under aerobic conditions.( 5) In the SPM of Lake Chaohu,residual p,p'-DDT and o,p'-DDT may have adverse impact on the aquatic organisms.

Organochlorine pesticides in the dust fall around Lake Chaohu, the fifth largest lake in China

The residual levels of organochlorine pesticides (OCPs) in the dust fall around Lake Chaohu were measured using gas chromatography mass spectrometry from April 2010 to March 2011. The fluxes, components, temporal-spatial variations, and sources of OCPs were also analyzed. Twenty-one types of OCPs were detected in the dust fall samples around Lake Chaohu, with a total concentration of 51.54 ± 36.31ng/g and a total flux of 10.01 ± 13.69ng/(m(2)day). Aldrin (35.3%), endosulfan (39.1%), dichlorodiphenyltrichloroethanes (DDTs) (49.8%), and isodrin (37.1%) were the major OCPs in the spring, summer, autumn, and winter, respectively. Both the residual level and the flux were higher in the spring than in other seasons and higher at the outer lake sampling sites than inner lake sampling site. The potential source of the hexachlorcyclohexanes in the dust fall may be recent lindane usage. The DDTs mainly came from historical dicofol usage, and a significant input of DDT was found during April and June. The presence of endosulfan may be due to the present use of technical endosulfan. The aldrin in the dust might be due to its occasional usage, and isodrin may be a result of long-distance transport from other countries.

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

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

Occurrence and distribution of organochlorine residues in surface sediments of the Candarli Gulf (Eastern Aegean)

The residual levels of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) were determined in surface sediments collected from Candarli Gulf. Total concentrations of OCPs and PCBs in sediments ranged from 10.2 to 57.3 and 2.8 to 205ngg−1dwt, respectively. DDTs in sediments were derived from the aged and weathered agricultural soils in 61% of the sampling stations while 39% of the sites originated from the recent DDT inputs. Their concentrations appeared to be relatively low by global standards and only sediments receiving the impact from the Bakircay River and petrochemical industry approached the sediment quality guidelines for PCBs and DDTs. Based on ERL/ERM guidelines, DDT and PCBs posed ecological risk to the bottom-dwelling consumers.

Residues of organochlorine pesticides in vegetables marketed in Greater Accra Region of Ghana

Residual levels of organochlorine pesticides (OCPs) were determined in 240 samples of vegetables collected from selected markets from Greater Accra region of Ghana in July 2010 to February 2011. The determination was done using gas chromatography with electron capture detector (GC–ECD). The compounds targeted were lindane, heptachlor + its epoxide, endrin, dieldrin, o,p′-DDE, p,p′-DDE, o,p′-DDD, o,p′-DDT and p,p′-DDT. The results indicated that all the vegetables sampled had some levels of one or more OCPs in them. Residues of pesticides were found in 71.9% of all the vegetable samples analyzed indicating high incidence of these xenobiotics in the vegetables from the markets and 31.48% samples were above the maximum residue levels (MRLs). The most frequently found and abundant pesticides were the metabolites of DDT (o,p′-DDE, p,p′-DDE and o,p′-DDD), followed by lindane and then o,p′-DDT. The residue levels and the detection rate of the OCPs indicate that, vegetables from supermarket had higher OCPs levels, followed by roadside grocery stores and open markets. The results recommend the need for regular monitoring of a greater number of samples for long periods for pesticide residues especially in fruits and vegetables to protect consumers’ health.

Occurrence and profiles of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in soils from a typical e-waste recycling area in Southeast China

Surface soils collected from Taizhou, a typical e-waste recycling area in Southeast China, were analyzed for the residues of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and organochlorine pesticides (OCPs) by using microwave-assisted extraction and gas chromatography -mass spectrometry (GC-MS). The total concentrations of 16 PAHs in US EPA's priority list (ΣPAHs), six indicator PCBs (ΣPCBs), 15 OCPs widely used in China (ΣOCPs) in soils ranged from 125 to 4737 ng/g (average: 854 ng/g), from not detected to 55.4 ng/g (3.16 ng/g), and from 47.9 to 820 ng/g (276 ng/g), respectively. Individual PAHs were ubiquitously found in soil samples with detected ratio of 96% and their residual levels were comparable with those of serious polluted sites. Principal component analysis in combination with diagnostic ratios suggested that the combustion of coal, wood, and plastic wastes that are closely associated with illegal and unsafe recycling operations of e-wastes was the main source of PAHs in this area. Compared with other polluted sites, the PCBs residues in soils were generally low except for those in the major recycling site. The residual levels of OCPs in this region were also relatively higher and hexachlorocyclohexane (HCH), dichlorodiphenyltrichloroethane (DDT) and its metabolite forms including dichlorodiphenyldichloroethane (DDD) and dichlorodiphenyldichloroethylene (DDE), hexachlorobenzene (HCB), and dicofol were dominant species. The composition analysis indicated that the HCHs residues in soils might originate from the application of lindane (pure γ-HCH) and parts of DDTs possibly from the wide use of dicofol with high impurity of DDT compounds in this region.

Dietary exposure to persistent organochlorine pesticides in 2007 Chinese total diet study

Dietary exposure to persistent organochlorine pesticides (OCPs) was assessed for Chinese populations, using the total diet study (TDS) approach in 2007. Multistage random cluster sampling method was used in this study. 108 composite samples, representative of foods “as consumed” by the Chinese were analyzed for residues of OCPs by a multi-residue method. The result showed that hexachlorobenzene (HCB), dichloro-diphenyl-trichloroethane (DDT), chlordane compounds (CHLs), hexachlorocyclohexane (HCH) and heptachlor could be detected in, respectively 84%, 39%, 37%, 13% and 5% of all samples. Concentrations of DDT in all samples ranged from undetectable levels to 72.2μg/kg. Others were minor components in the OCPs profile. The residual levels of OCPs were significantly below the Extraneous Maximum Residue Limits (EMRLs). Based on the 2000 nationwide food consumption survey, the average dietary exposure of the Chinese to DDT, HCH, HCB, CHLs, and heptachlor was estimated to be 0.016, 0.002, 0.009, 0.006, and 0.001μg/kg body weight per day respectively, showing a significant decrease trend compared with the past. The major food groups contributing to dietary OCPs were aquatic foods, meats, and cereals. The average and high end estimated daily intakes of different OCPs for the Chinese were both lower than the tolerable daily intake (TDI) suggested by authorities indicating low health risk of OCPs dietary exposure among Chinese adults at present. However, the risk of carcinogenicity of the OCPs should be concerned with if the carcinogenicity effects from the exposures to these OCPs were considered.

Determination of organochlorine pesticide and polychlorinated biphenyl levels in adipose tissue of infertile men

During the recent two decades, a remarkable drop in fertility rates has been noticed almost all over the world. A series of studies have showed that environmental factors had the primary role causing the observed adverse trends in the male reproductive health problems. Especially chlorinated hydrocarbons, for instance polychlorinated biphenyls (PCB) and pesticides, could mimic or antagonize the effects of steroid hormones, like estrogens and androgens and possibly interfering with male reproductive capacity. Organochlorine pesticides (OCPs) (i.e. p.p'-DDT, endosulfan...) and PCBs are widespread used chemicals in agriculture and industry for different purposes all over the world. Although direct evidence is lacking, theoretical considerations and epidemiological evidence implicate these compounds as potential hazards to human and wildlife reproductive health. For this purpose, in this study adipose tissue samples have provided from healthy males which were diagnosed as infertile men living in Ankara, Turkey at least for 5 years. Residual levels of OCPs (alpha-BHC, beta-BHC, gamma-BHC, HCB, Endosulfan I, II, p,p'-DDE, and p,p'-DDT) and seven major persistent PCB congeners (PCB 28, 52, 101, 118, 138, 153, and 180) were measured in 25 infertile men and 21 healthy men's adipose tissue samples by GC-ECD. Levels of OCPs and PCBs in adipose tissue of infertile men compared with those provided from controls. When the concentrations of each of the OCP were compared between the fertile and infertile groups, no statistical significance was obtained. Concentrations of each of the PCB congeners were compared between the fertile and infertile groups, no statistical significance was obtained (p > 0.05), except for 2,2',5,5'-Tetrachlorobiphenyl (PCB 52) (p = 0.032) and 2,2',3,4,4',5,5'-heptachlorobiphenyl (PCB 180) (p = 0.017).

Organochlorine pesticides in seafood products from Southern China and health risk assessment

Seafood consumption is an important route of human exposure to organic contaminants. Residual levels of organochlorine pesticides (OCPs), including DDTs, hexachlorocyclohexanes (HCHs), heptachlor, aldrin, alpha-endosulfan, beta-endosulfan, dieldrin, endrin, endrin aldehyde, endrin ketone, methoxychlor, endosulfan sulfate, and heptachlor epoxide, were determined in a wide variety of seafood products collected from 11 coastal cities in southern China in June and October 2005. The results indicated that OCPs were predominated by DDTs and HCHs. The concentrations of other OCP components generally were low and were detectable in a small number of seafood samples only, probably reflective of the generally low levels of these OCPs in the study region and low bioaccumulation potentials in the species under investigation. Risk assessment against various standards clearly showed that seafood products were highly contaminated by DDTs and may pose health threat to local residents and the consumers all over the world. Furthermore, other OCP components, such as dieldrin and heptachlor, also impose lifetime cancer risk, especially to residents of coastal regions who often consume more seafood than those living inland. Therefore, continual monitoring of OCPs in various environment compartments, including biota and abiota, urgently is needed to mitigate effectively the impact of OCPs, particularly DDTs, on human health and the ecological environment.