Total Organochlorine Pesticides Research Articles

Diffusion of organochlorine (OCPs) and cypermethrin pesticides from rohu (Labeo rohita) internal organs to edible tissues during ice storage: a threat to human health.

The migration of organochlorine pesticides (OCPs) and cypermethrin residues from internal organs to edible tissues of ice-held Labeo rohita (rohu) was investigated in this study. The liver (246µg/kg) had the highest level of ∑OCP residues, followed by the gills (226µg/kg), intestine (167µg/kg), and muscle tissue (54µg/kg). The predominant OCPs in the liver and gut were endosulfan (53-66µg/kg), endrin (45-53µg/kg), and dichloro-diphenyl-trichloroethane (DDT; 26-35µg/kg). The ∑OCP residues in muscle increased to 152µg/kg when the entire rohu was stored in ice, but they decreased to 129µg/kg in gill tissues. On days 5 and 9, the total OCPs in the liver increased to 317µg/kg and 933µg/kg, respectively. Beyond day 5 of storage, total internal organ disintegration had led to an abnormal increase in OCP residues of liver-like mass. Despite a threefold increase in overall OCP residues by day 9, accumulation of benzene hexachloride (BHC) and heptachlor was sixfold, endrin and DDT were fourfold, aldrin was threefold, and endosulfan and cypermethrin were both twofold. Endosulfan, DDT, endrin, and heptachlor were similarly lost in the gills at a rate of 40%, while aldrin and BHC were also lost at 60 and 30%, respectively. The accumulation of OCP residues in tissues has been attributed to particular types of fatty acid derivatives. The study concluded that while pesticide diffusion to edible tissues can occur during ice storage, the levels observed were well below the allowable limit for endosulfan, endrin, and DDT.

Characterization of organochlorine pesticides in the surface waters of Marchica Lagoon, Morocco

The main objective of this initial study is to assess the extent of surface water contamination in Marchica Lagoon caused by organochlorine pesticides (OCPs) historically used in agriculture through a sampling network consisting of eight stations covering all areas of the lagoon during the 2022 summer season. Located on Morocco’s Mediterranean coast, the lagoon has undergone several restoration actions since 2010 to improve its environmental state. However, this ecosystem is under constant pressure from its watershed, which can convey water pollution from agricultural, industrial, mining, and domestic sources, making continuous monitoring essential. Eight organochlorine pesticides (Alpha HCH, Beta HCH, Gamma HCH, Aldrin, Dieldrin, DDD, DDE, and DDT) were detected by gas chromatography-mass spectrometry (GC-MS) using the SIM (Selected Ion Monitoring) method. The results revealed OCPs contamination of the lagoon’s surface waters; the spatial variation of total OCPs concentrations (Σ8OCPs) ranged from 7.58 to 18.79 ng/l. The predominant element detected was β-HCH (lindane), recorded between the Bouarg channel and Selouane wadi, an area characterized by intensive agriculture.

Association between persistent organic pollutants in human milk and the infant growth and development throughout the first year postpartum in a cohort from Rio de Janeiro, Brazil.

Persistent organic pollutants (POPs) are compounds that are recalcitrant and ubiquitous that bioaccumulate in human milk (HM) and can impact infant growth and development. We explore the association between POP concentration in HM at 2-50 days postpartum and infant growth and development trajectory throughout the first year of life. A cohort of 68 healthy adult Brazilian women and their infants were followed from 28 to 35 gestational weeks to 12 months postpartum. HM samples were collected between 2 and 50 days postpartum, and POP concentrations were analyzed using gas chromatography with mass spectrometry. Concentrations of POPs >limit of quantification (LOQ) were defined as presence, and concentrations ≤LOQ as an absence. Growth z-scores were analyzed according to WHO growth charts and infant development scores according to Age & Stages Questionnaires at 1 (n = 66), 6 (n = 50), and 12 months (n = 45). Linear mixed effects (LME) models were used to investigate the association of POPs in HM with infant growth and development. Benjamini-Hochberg (BH) correction for multiple testing was performed to reduce the false discovery ratio. P < 0.1 was considered for models with the interaction between POPs and time/sex. After BH correction, adjusted LME models with time interaction showed (1) a positive association between the presence of β hexachlorocyclohexane and an increase in head circumference-for-age z-score (β = 0.003, P = 0.095); (2) negative associations between total POPs (β = -0.000002, P = 0.10), total organochlorine pesticides (β = -0.000002, P = 0.10), and dichlorodiphenyldichloroethylene concentrations in HM (β = -0.000002, P = 0.10) and fine motor scores. No statistical difference between the sexes was observed. Postnatal exposure to organochlorine pesticides in HM shows a positive association with the trajectory of head circumference-for-age z-score and a negative association with the trajectories of fine motor skills scores. Future studies on POP variation in HM at different postpartum times and their effect on infant growth and development should be encouraged.

Polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in water-sediment system of southern Mediterranean: Concentration, source and ecological risk assessment

Polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were studied in the Nile Delta area of Egypt's southern Mediterranean for their environmental impacts, probable sources, and ecological risk assessment. Using the Gas Chromatography Triple Quadrupole technique, the residues of 16 OCPs and 18 PCBs were determined. The total OCPs content in the seawater and sediment samples ranged from 0.108 to 10.97 μg/L and 0.301 to 5.268 ng/g, respectively, while the PCBs residues had values between 0.808 and 1069.75 μg/L in seawater and between not detected and 575.50 ng/g in sediment samples. The findings of the risk evaluation showed that, except for endosulfan-I, OCPs caused little harm in seawater. However, PCB180, PCB153, PCB156, PCB126 and PCB138 posed a comparatively significant risk. The concentration of DDTs was higher than the effect range low and threshold effect level but remained below the effect range median and probable effect level, posing a minimal ecological concern.

Organochlorine pesticide residues persist throughout the sugar production process

Thailand, one of the world’s largest sugarcane producers, has historically used organochlorine pesticides (OCPs) extensively in its plantations. Therefore, OCP residues are anticipated in plantation soil. However, the persistence of these compounds during sugar production is ambiguous. Thus, this study investigated the OCP residues in sugarcane at the different processing stages. Five product samples, i.e., sugarcane juice, bagasse, raw sugar, granulated white sugar, and molasses were obtained from different regions in Thailand. High concentrations of p,p′-dichlorodiphenyltrichloroethane (p,p′-DDT), γ-hexachlorocyclohexane (γ-HCH or lindane), and cyclodiene derivatives such as aldrin, dieldrin, heptachlor and its epoxide were found in the samples. This is surprising because the OCP use in sugarcane plantations has been long banned in Thailand. Bagasse and raw sugar had the highest total OCP concentrations of 1.0393 ± 0.7555 mg/kg and 0.9658 ± 0.8209 mg/kg, followed by white sugar (0.1616 ± 0.1311 mg/kg), molasses (0.0813 ± 0.1195 mg/kg), and sugarcane juice (0.0173 ± 0.0112 mg/kg). This study offers comprehensive information on the fate of OCPs during the entire sugarcane processing stage, from the cane to the final granulated sugar. The findings also suggest persistent OCP presence in plantation soil, possibly due to illegal use.

Maternal exposure to organochlorine pesticides and anthropometrics of newborns – a hospital-based cross-sectional study in rural and urban settings in Armenia

The study objective was to determine a possible association between maternal exposure to organochlorine pesticides (OCPs) and anthropometric measures at birth in group of postpartum women in urban and rural areas of Armenia. The anthropometric measures of infants were obtained from birth records and gamma-hexachlorocyclohexane (γ-HCH), dichlorodiphenyltrichloroethane (DDT), dichlorodiphenyldichloroethylene, and dichlorodiphenyldichloroethane were measured in breast milk. Gas-liquid chromatography with electron capture detection was used to identify OCPs. Total OCPs and DDTs were calculated, and the anthropometrics were analyzed for sex and areas, and group differences were compared (Student’s t-test). Both individual OCPs and total OCPs and DDTs were significantly higher in rural samples than in urban ones (P < 0.01–0.000), with lower and upper quartiles differing by 2.6-fold and 3.1-fold, respectively (P < 0.000). There was no association between the anthropometrics and OCPs levels in rural or urban areas. However, this does not rule out the possibility of OCPs impact on health later in life. To our knowledge, this was the first study addressing these issues in Armenia. The results obtained will provide data on the current situation regarding birth outcomes in terms of prenatal exposure to OCPs in Armenia and will contribute to the available results from previous studies.

Impact of thermal cooking processes on organochlorine pesticide residues (OCPs) in the edible green seaweed, Ulva lactuca, and associated human health risk assessment

Seaweeds are emerging natural food items in different countries. However, they are known to be potentially contaminated by chemical residues. This study examined the impact of domestic cooking methods such as boiling, steaming, and microwave cooking on reduction of organochlorine pesticide (OCP) level in edible green seaweed Ulva lactuca. Thermal cooking processes significantly influences the OCP residues in U. lactuca. The OCP residue concentration decreased after boiling, steaming, and microwave cooking compared to raw seaweed. The total OCP residue concentration in raw seaweed was 0.707 mg/kg, which reduced to 0.168, 0.178, and 0.241 mg/kg after boiling, microwaving, and steam cooking, respectively. Aldrin, endrin, DDT, and endosulfan were predominant OCPs in raw and processed seaweeds. Health risk due to OCP residues was evaluated using food consumption data, acceptable daily intake, and safety indices such as hazard quotient (HQ) and hazard index (HI). The HQ and HI values did not exceed the unit value (HQ, HI < 1), indicating that the level of OCP residues in U. lactuca does not pose any appreciable risk to the consumers. Therefore, the research finding establishes that different thermal cooking processes reduce the OCP residue concentration in U. lactuca.

Persistent Organic Pollutants in Sewage Sludge: Occurrence, Temporal Concentration Variation and Risk Assessment for Sewage Sludge Amended Soils

In this study, the occurrences, temporal concentration variations and ecotoxicological risks were determined for 18 polycyclic aromatic hydrocarbons (PAHs); 7 congeners of polychlorinated biphenyls (PCBs), and 18 selected organochlorine pesticides (OCPs) in the anaerobically digested sewage sludge samples obtained from a conventional wastewater treatment plant (WWTP) in Konya, Turkey. Flowrate of the evaluated WWTP was 200,000 m3/day, with the production of 140 tons/day treated sewage sludge. Total 18 PAHs were in the range of 1,203 – 17,599 μg/kg of dry matter (dm); total PCBs were in the range of 51.26 – 561.37 μg/kg dm, and total OCPs were in the range of 4.90 – 13.11 μg/kg dm. The highest concentrations were determined for fluoranthene among PAHs, with 2445 μg/kg dm, PCB118 congener with 514 μg/kg dm, and δ-HCH among OCPs with 2.44 μg/kg dm. Considering the average daily production amounts of treated sludge, the highest mass loads were 1,785 g/day for total PAHs; 79 g/day for total PCBs; and 1 – 2 g/day for total OCPs, while the annual mass load was estimated to be approximately 7.3 kg. An ecotoxicological risk assessment was performed by estimation of risk quotients (RQs). High risk for soil ecosystem was identified due to PAHs and PCBs ingredient of sludge, while lower risk was determined for OCPs compounds. The highest RQ values were determined for pyrene (RQ: 1337) among PAHs, PCB118 congener (RQ: 7608), and γ-HCH (RQ: 5.23) among OCPs. Findings of this study show that sewage sludge can be an important source in the spread of persistent pollutants to the environment, and may pose a risk for soil ecosystem.

Organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in adipose tissue of women from Grand Tunis and their association with demographic factors and dietary habits

Dichlorodiphenyl trichloroethane and its metabolites (DDTs), hexachlorocyclohexane isomers (HCHs), hexachlorobenzene (HCB) and polychloronated biphenyls (PCBs) were measured in 25 woman adipose tissues collected in 2016 from Grand Tunis, Tunisia. p,p’-DDE, p,p’-DDT, HCB and β-HCH were the dominant organochlorine pesticides (OCPs) in decreasing order in all samples. The total OCP levels varied from 79 to 343 ng g−1 lipid with a median value of 189 ng g−1 lipid and DDTs contributed approximately 88% to sum OCP. The ratio of p,p’-DDT/p,p’-DDE across all samples is below one, which suggests mainly historic exposure but may indicate some recent exposure to the banned pesticide. The median concentration of PCBs was 109 ng g−1 lipid and ranged between 27 and 204 ng g−1 lipid. PCB-153, PCB-180, PCB-138 and PCB-170 were the most abundant congeners, which contributed about 78% of the total PCBs. Spearman analysis showed that dominant organochlorine compounds (OCs) are highly positive correlated except for PCB-28/31, indicating that women from Tunis are exposed via similar routes. Inhalation exposure could be a possible pathway for the uptake of the less chlorinated congeners. We found positive and statistically significant association with subjects age for HCB (r = 0.517; p = 0.009) and PCBs (r = 0.65; p = 0.001) levels and a weak age-dependent accumulation was found for HCHs (r = 0.375; p = 0.065) and DDTs (r = 0.388; p = 0.056). The concentrations of OC subgroups were not associated with BMI, parity and residence. No association was observed between fish, red/white meat, milk and dairy products consumption and levels of HCB, HCHs and PCBs. DDTs levels were significantly correlated only with milk (p = 0.048) and milk products (p = 0.047) intake.

Association between Organochlorine Pesticides and Vitamin D in Female Subjects.

In human population studies, organochlorine pesticides (OCPs) have been linked to vitamin D deficiency. Therefore, this study examined the association between OCPs, vitamin D3 (cholecalciferol, 25(OH)D3), and the active metabolite 1,25-dihydrovitamin D3 (1,25(OH)2D3) in a cohort of non-obese women. The serum samples of 58 female participants (age-31.9 ± 4.6 years; body mass index (BMI)-25.7 ± 3.7 kg/m2) were screened for 10 indicator OCPs. 25(OH)D3 and 1,25(OH)2D3 levels were determined via isotope dilution liquid chromatography tandem mass spectrometry. In this cohort, the 25(OH)D3 and 1,25(OH)2D3 levels were 22.9 ± 11.2 ng/mL and 0.05 ± 0.02 ng/mL, respectively, with 28 participants classified as 25(OH)D3-deficient (<50 nmol/L). In the study cohort, no correlations were found between individual or total OCPs (ƩOCPs) and 25(OH)D3. p,p'-dichlorodiphenyldichloroethylene (DDE) and ƩOCPs correlated positively with 1,25(OH)2D3, with the latter being negatively correlated with estimated glomerular filtration rate (eGFR). In women with sufficient 25(OH)D3 levels, p,p'-dichlorodiphenyltrichloroethan (DDT) was positively correlated with 1,25(OH)2D3, whilst in the deficient group, hexachlorobenzene (HCB) and p,p'-(DDE) were positively correlated with 1,25(OH)2D3, β-Hexachlorocyclohexane (HCH) was positively correlated with 25(OH)D3, and none of the OCPs were associated with measures of renal function. Overall, OCPs and ƩOCPs were not associated with 25(OH)D3, suggesting that they are unrelated to vitamin D deficiency, but p,p'-DDE and ƩOCPs correlated positively with active 1,25(OH)2D3, while ƩOCPs correlated negatively with eGFR, suggesting a possible renal effect. Analysis of vitamin D deficiency revealed an association between β-HCH and 25(OH)D3, and between HCB and p,p'-DDE and 1,25(OH)2D3, suggesting that OCP effects may be enhanced in cases of vitamin D deficiency.

Occurrence, distribution, and risk assessment of halogenated organic pollutants (HOPs) in marine fish muscle: The case study of Vietnam

Halogenated organic pollutants (HOPs), including polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), and chlorophenols (CPs), were identified in three marine fish species in Vietnam. Total PCBs, OCPs, and CPs concentrations ranged from 4.5 to 711.6 ng g−1 lipid weight (lw), 69.9–2360 ng g−1 lw, and 208.1–3941.2 ng g−1 lw, respectively. CPs were the most frequently detected pollutants in the marine environment of Vietnam of the three HOPs studied, followed by OCPs and PCBs. There are significant differences in HOPs between three types of seafood in Vietnam, including yellowstripe scad, Indian mackerel, and silver pomfret in this study. Notably, the types and amounts of HOPs found in the fish were differently influenced by the economic and industrial activities of the sampled areas. Despite these findings, the consumption of HOP-contaminated fish from the study areas was found not to pose any significant health risks to Vietnam's coastal population.

Nationwide assessment of atmospheric organochlorine pesticides over a decade during 2008–2017 in South Korea

Long-term nationwide atmospheric monitoring of organochlorine pesticides (OCPs) was performed in South Korea during 2008–2017. Their occurrences, seasonal and temporal variability, sources, and effect of ambient temperature were investigated. The OCPs are pronounced with a mean concentration of total OCPs ranging from 5.2 to 256 pg/Sm3. However, a decrease of 54 % was observed in the mean concentration of total OCPs from 2008 to 2017 associated with regulatory actions. OCP concentrations did not show any variations between the different site types, and OCPs were ubiquitously present at all site types. The mean concentration of total OCPs in summer was two-fold higher than in winter. The concentrations of DRINs, DDTs, ENDOs, and HCHs were significantly higher in summer, but the concentrations of chlordane and heptachlor were higher in winter. The diagnostic ratios identified major sources as ongoing sources, past use, and atmospheric transport. Clausius Clapeyron plots strongly suggested the re-emission of α-endosulfan, β-endosulfan, α-HCH, and β-HCH, and ΔHsa (enthalpy of surface air exchange) values suggested the influence of the transport and/or new sources on aldrin, dieldrin, and chlordane. The occurrence of OCPs due to re-emissions, ongoing sources, and long-range atmospheric transport could be a challenge towards the complete phase-out of OCPs in South Korea.

Detection of organochlorine pesticides in estuarine sediments of protected wetlands in Taiwan using high‐resolution gas chromatography/high‐resolution mass spectrometry and gas chromatography‐electron capture detector

AbstractTrace residues of organochlorine pesticides (OCPs) in estuarine surface sediments were investigated at three protected wetlands in southern Taiwan using high‐resolution gas chromatography/high‐resolution mass spectrometry (HRGC/HRMS) and gas chromatography‐electron capture detector (GC‐ECD). This study facilitates the development of new strategies for investigating OCPs, particularly at background levels. Linear relationships were obtained between total OCP concentrations (∑OCP), as analyzed by HRGC/HRMS, and the sediment's total organic carbon (TOC) and water content. It contrasted with the results acquired by GC‐ECD, where no significant relationship was found. GC‐ECD is a rugged option for daily routine practice, particularly in cases of patterns yielded by GC‐ECD is clear; the HRGC/HRMS method provides more reliable qualitative and quantitative capabilities and is highly recommended for studying the fate of OCPs and carrying out risk assessments. The average ∑OCP of these three wetlands by HRGC/HRMS was found in a range of 0.214 to 1.049 ng/g dry weight. The highest OCP level might be attributed to associated irrigation systems receiving massive discharges of domestic sewage from an urban area upstream of the wetland. The ratio of dichlorodiphenyltrichloroethane (DDT) to its metabolites indicated that the DDT residue in these areas was from aged input. According to sediment quality guidelines, adverse ecotoxicological effects of OCPs upon sediments were not expected in these protected wetlands.

Mapping the Contribution of Biomass Burning to Persistent Organic Pollutants in the Air of the Indo-China Peninsula Based on a Passive Air Monitoring Network.

Biomass burning (BB) is an important source of atmospheric persistent organic pollutants (POPs) across the world. However, there are few field-based regional studies regarding the POPs released from BB. Due to the current limitations of emission factors and satellites, the contribution of BB to airborne POPs is still not well understood. In this study, with the simultaneous monitoring of BB biomarkers and POPs based on polyurethane foam-based passive air sampling technique, we mapped the contribution of BB to polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in the Indo-China Peninsula. Spearman correlations between levoglucosan and 16 PCBs (rs = 0.264-0.767, p < 0.05) and 2 OCPs (rs = 0.250-0.328, p < 0.05) confirmed that BB may facilitate POP emissions. Source apportionment indicated that BB contributed 9.3% to the total PCB and OCP mass. The high contribution of positive matrix factorization-resolved BB to PCBs and OCPs was almost consistent with their concentration distributions in the open BB season but not completely consistent with those in the pre-monsoon and/or monsoon seasons. Their contribution distributions may reflect the use history and geographic distribution in secondary sources of POPs. The field-based contribution dataset of BB to POPs is significant in improving regional BB emission inventories and model prediction.

Biomonitoring of organochlorine pesticides and cancer survival: a population-based study.

Organochlorine pesticides (OCPs) are endocrine-disrupting chemicals (EDCs) that even at very low levels can cause cancer by increasing the activity of tumor cells and suppressing the immune system. There is also little information on OCPs and survival after diagnosis. The aim of this study was to monitor the concentration of OCPs in the blood serum of cancer patients and its relationship with their socio-demographic characteristics and ultimately that impact on survival time and hazard ratio (HR). This cross-sectional study included 89 diagnosed patients with cancer in Isfahan, Iran. 12 types of OCPs were measured in serum by gas chromatography (7GC) with an electron capture detector and equipped with mass spectrometer (MS). Also, participants' questionnaire was completed to collect information. T-test, ANOVA, and Chi-square tests were used to evaluate the association between serum levels of OCPs and quantitative and qualitative information of patients. Survival analysis was also examined based on Kaplan-Meier method, log-rank test, and Cox model. The mean of total OCPs in patients' serum was calculated to be 1.82 ± 1.36μg/L. Concentration of 2,4' DDE had a significant relationship with body mass index (BMI) (kg/m2) (P < 0.05). In addition, gender revealed a significant correlation in estimating survival time (P < 0.05). Non-exposure to OCPs showed a positive effect on increasing the life expectancy of patients. Lindane and endosulfan increased the risk of death by 16% and 37%, respectively, with insignificant P value (P > 0.05). The findings of the present study showed adverse effects of OCPs on patients' survival time and increased mortality of HR. Moreover, as the first research conducted in the study area, it is suggested management of environmental, individual and social factors that could be influenced the biological accumulation of OCPs in humans and cause health promotion.

Occurrence, behavior and the associated health risk of organochlorine pesticides in sediments and fish from Bahía Blanca Estuary, Argentina.

Organochlorine pesticides (OCPs) were assessed for their occurrence, behavior and the associated human health and ecological risks in four fish species (Micropogonias furnieri, Cynoscion guatucupa, Mustelus schmitti, and Ramnogaster arcuata) and sediments from the Bahía Blanca estuary, Argentina, an important coastal environment of South America. Total OCPs values ranged from 0.86 to 6.23ng/g dry weight in sediments and from <LOD (method detection limits) to 0.74ng/g wet weight in fish. While lindane and α-endosulfan were the dominant congeners in sediments, β-endosulfan and p,p'-DDE were dominant in fish. OCP levels and residues patterns varied within the fish species and life stage. Finally, after cancer and non-cancer risk analysis, results concluded that the consumption of fish from the estuary would pose no health threats associated with these pollutants.

Levels, Distribution and Health Risk Assessment of Organochlorine Pesticides in Agricultural Soils from the Pearl River Delta of China.

To reveal the pollution status of agricultural soils along with rapid urbanization and economic growth, a large regional survey of organochlorine pesticides (OCPs) in agricultural soils was conducted in the Pearl River Delta (PRD) of China. The results showed that the total residues of 23 OCPs were in the range of ND-946 ng/g dry weight. OCP residues showed distinct spatial distribution characteristics within the PRD. OCPs were mainly found in areas with high agricultural production and industrial activities. Higher OCP concentrations were observed in the top layer of soil, while the concentration decreases to marginal levels when the soil depth is greater than 50 cm. OCPs are mainly derived from historical use. Hexachlorocyclohexanes (HCHs) in the top soil of the study area are mainly from the use of lindane. Soil pH was negatively and significantly correlated with total OCP concentration. The human health risk assessment showed no health risk for children, while for adults, there is a non-carcinogenic risk, which needs to be noticed. Agricultural activities and industrial production have made the region a pollution hotspot and should arouse more stringent regulation to protect the environment and food safety.

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

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

Environmental and biological monitoring of organochlorine pesticides in the city of Salamanca, Mexico.

The former Tekchem Industrial Unit located in the city of Salamanca, Mexico, constitutes an environmental liability in which the presence of high levels of organochlorine pesticides (OCPs) has been reported. In the present study, levels of OCPs were quantified using gas chromatography-mass spectrometry in 52 soil samples and in 88 blood samples from school-age children in the city of Salamanca. A median concentration of 70.6ng/g (6.93-3299) was obtained for total OCPs in soil, while for the total sum of dichlorodiphenyltrichloroethane (DDT) the value was 49.6ng/g (6.93-3276). In children, the median level of the total sum of OCPs was 390ng/g lipid (7.34-14,895), and for the total sum of DDT was 175ng/g lipid (< LOD-14,802). The OCPs that resulted in highest concentrations in soil were DDT and its metabolites, as well as aldrin and heptachlor epoxide, while in blood the highest levels corresponded to 4,4'-dichlorodiphenyltrichloroethane (4,4'-DDT) and its metabolites, followed by heptachlor and heptachlor epoxide. The spatial distribution of the concentrations of OCPs in soil shows that the facilities of Tekchem may be a significant potential source for the dispersion of these compounds toward the metropolitan area of Salamanca. The results obtained in the present study demonstrate the presence of OCPs in soil and in child population, providing important bases to study the problem from a broader perspective, while reiterating the importance of continuing efforts to generate resolute and precautionary measures with respect to the environmental liability of Tekchem.

Organochlorine pesticides (OCPs) in corals and plankton from a coastal coral reef ecosystem, south China sea

Recent studies have indicated that coral mucus plays an important role in the bioaccumulation of a few organic pollutants by corals, but no relevant studies have been conducted on organochlorine pesticides (OCPs). Previous studies have also indicated that OCPs widely occur in a few coral reef ecosystems and have a negative effect on coral health. Therefore, this study focused on the occurrence and bioaccumulation of a few OCPs, such as dichlorodiphenyltrichloroethanes (DDTs), hexachlorobenzene (HCB) and p,p′-methoxychlor (MXC), in the coral tissues and mucus as well as in plankton and seawater from a coastal reef ecosystem (Weizhou Island) in the South China Sea. The results indicated that DDTs were the predominant OCPs in seawater and marine biota. Higher concentrations of OCPs in plankton may contribute to the enrichment of OCPs by corals. The significantly higher total OCP concentration (∑8OCPs) found in coral mucus than in coral tissues suggested that coral mucus played an essential role in resisting enrichment of OCPs by coral tissues. This study explored the different functions of coral tissues and mucus in OCP enrichment and biodegradation for the first time, highlighting the need for OCP toxicity experiments from both tissue and mucus perspectives.