Dissolved legacy and emerging organochlorine pesticides in the Antarctic marginal seas: Occurrence, sources and transport

Polar regions are recognized as final sinks of the persistent contaminants, however, environmental investigations in the Antarctica are greatly limited by harsh field conditions. In this study, seawater samples were collected in the Antarctic marginal seas during the austral summer of 2021 to investigate the environmental behavior and fate of organochlorine pesticides (OCPs). The concentrations and source markers of representative legacy hexachlorocyclohexane (HCH), hexachlorobenzene (HCB) and dichlorodiphenyltrichloroethanes (DDTs) indicated the coexistent sources of historical residues and fresh inputs. While the emerging OCPs, including quintozene, pentachloroaniline and dichlobenil, showed relatively lower detection frequency. Due to the differences in temperature and sea ice coverage, dissolved OCPs generally displayed higher concentrations in the eastern Antarctic than those in the western Antarctic. The 'surface depleted and depth enrichment' vertical profile of representative OCPs in the continental shelf of Prydz Bay was jointly controlled by biological pump and water mass structure.

Miniaturized kapok fiber-supported liquid extraction for convenient extraction of pesticide residues in vegetable oils: Determination of organochlorine pesticides as a proof-of-concept study

In this paper, a miniaturized kapok fiber-supported liquid extraction (mini-KF-SLE) method was proposed for selective extraction of pesticide residues in vegetable oils. The natural kapok fiber was used as an inert oil support material based on its hydrophobic and lipophilic properties, and the extraction device was conveniently constructed by loading 15 mg of kapok fiber at the lower middle part of a 1-mL pipette tip. The vegetable oil sample (150 mg) without any pretreatment was directly loaded, followed by the addition of 150 μL of acetonitrile (ACN) as the extractant. After static extraction for 30 min, the extractant was pipetted out with a pipettor. As the proof of concept, it was applied for extracting eight organochlorine pesticides (OCPs) from vegetable oils and the eluate was analyzed by gas chromatography-electron capture detector (GC-ECD). Under optimized conditions, the extraction recoveries of OCPs were calculated to be in ranges of 35.8-79.5%. The satisfied quantitation ability was verified by the established method with coefficients of determination (R²) being greater than 0.99. The limits of detection (LODs) were in ranges of 2.0-50.0 ng/g. The relative recoveries were in ranges of 78.3-117.0% with the inter-/intra-day relative standard deviation (RSD) both being less than 13.3%. The potential of mini-KF-SLE to extract other kinds of pesticides was further verified by the successful extracting three triazole pesticides in vegetable oils with good extraction recoveries (>41.4%). The proposed mini-KF-SLE in combination with instrument detection techniques has the great potential in the low-cost and high-throughput determination of various pesticide residues in vegetable oils.

A global review of the temporal and spatial patterns of DDT and dieldrin monitoring in raptors

Concentrations of organochlorine pesticides have been extensively monitored in birds, particularly from higher trophic guilds such as raptors. While monitoring of raptors has been ongoing for decades, patterns from monitoring activities have never been summarised on a global scale. In this study, we undertake a review to better describe the monitoring of two widespread organochlorine pesticides monitored globally in raptors, DDT and dieldrin. We provide a historical retrospective on the monitoring effort of a global environmental issue. Sampling was heavily biased geographically to the global north, with more than 90 % of studies conducted in this socio-geographic region, most from Europe and North America. Although monitoring occurred from at least 114 species, most samples came from relatively few species, with three species (Eurasian Sparrowhawk Accipiter nisus, Bald Eagle Haliaeetus leucocephalus, and Peregrine Falcon Falco peregrinus) comprising 50 % of samples. The types of raptors sampled have changed over time, with avian and mammal specialists dominating samples until the 1970s, but more diverse dietary guilds monitored in later decades, and greater proportions of samples coming from generalist species. The three most sampled tissues (egg, liver, and plasma) comprised 84 % of all samples. Eggs were the earliest tissue examined and the only tissue sampled in all decades. The geographical bias in monitoring effort and relatively narrow species focus, suggests that patterns in these pesticides are unlikely to be fully representative of all global environments occupied by raptors. While DDT has been banned throughout most of the global north, it remains in use in the global south, yet monitoring effort in the south, does not match that of the north. While monitoring remains prevalent in the global north, contemporary monitoring is limited in the global south with less than 10 % of raptors sampled in Asia, Africa, and South America, over the last 3 decades.

Endosulfan use and the risk of thyroid cancer: an ecological study

Endosulfan, an organochlorine pesticide, has been understudied in the literature on thyroid cancer. The aim of this ecological study was to assess the correlation between endosulfan exposure and thyroid cancer incidence rates (IRs) in the United States (US). Age-adjusted thyroid cancer IRs per 100,000 people per state for the years 1999 to 2019 were obtained from the Center for Disease Control and Prevention (CDC). To assess the state-level use of endosulfan, data were obtained from the US Geological Survey (USGS). Endosulfan usage estimates (kilograms/acres cropland; quintiles) and thyroid cancer IRs were mapped together. The correlation between age-adjusted thyroid cancer IRs and statewide endosulfan use was calculated using the Spearman correlation. Overall endosulfan usage in the US trended downwards between 1992 and 2007 (T = -0.77; P < 0.001), while thyroid cancer IR trended upwards between 1999 and 2019 (T = 0.69; P < 0.001). There was a statistically significant correlation between 1992 endosulfan use and 2012 (r = 0.32; P = 0.03) and 2014 (r = 0.32; P = 0.03) thyroid cancer IRs. Although restrictions on endosulfan use seem effective, the potential impact of endosulfan exposure remains due to the persistent, semi-volatile, bioaccumulative, and biomagnifying properties of endosulfan metabolites in particular, indicating the need for future thyroid research of highly exposed populations.

Effervescent powder-assisted floating organic solvent-based dispersive liquid-liquid microextraction for determination of organochlorine pesticides in water by GC-MS

An effervescent powder-assisted floating organic solvent-based dispersive liquid-liquid microextraction was introduced for determination of 13 organochlorine pesticides in water samples. In this method, a less toxic low-density organic solvent was used as extraction solvent. The extraction solvent was dispersed in to the aqueous sample via CO₂ bubbles, in-situ generated up on addition of water to a falcon tube containing the mixture of effervescent powder precursors as well as the extraction solvent. Various experimental parameters such as effervescent and its weight fractions, extraction solvent type and its volume, the total mass of effervescent precursors, and the effect of salt were investigated and the optimal conditions were established. Under the optimum conditions, the proposed method exhibited good linearity for all target pesticides with the coefficient of determinations varying from 0.9981 to 0.9997. The limits of detection and quantification were within the range of 0.03-0.24 and 0.26-0.75 μg/L, respectively. The intra- and inter-day precisions which were expressed in terms of the relative standard deviation ranged from 0.33 to 4.47 and 0.51-5.52%, respectively. The enrichment factors and recoveries ranged from 24 to 293 and 76-116%, respectively. The proposed method could be used simple, cheap, fast, and environmentally friendly alternative for analysis of organochlorine pesticides from environmental water and other similar matrices.

Pesticide Exposure and Alzheimer's Disease: A Case-control Study

Aim / Objective: This study aimed to investigate the levels of organochlorine pesticides (OCPs) in the serum of Alzheimer's disease (AD) patients.

METHODS

63 AD patients and 50 healthy individuals participated, and the levels of some OCPs derivatives (including; α-HCH, β-HCH, γ-HCH, 2,4-DDT, 4,4-DDT, 2,4-DDE, and 4,4-DDE), total antioxidant capacity (TAC), protein carbonyl (PC), malondialdehyde (MDA), Nitric oxide (NO) along with the activity of superoxide dismutase (SOD), glutathione peroxidase (GPx), paraoxonase 1(PON1), and acetylcholinesterase (AChE) were measured.

RESULTS

The mean OCP level of OCPs in AD patients was significantly higher than in the control group. However, the patients' mean levels of TAC, PC, MDA and activity of SOD, GPx, PON1 and AChE were significantly lower than controls. A significant positive correlation was also observed between 2,4-DDE and MDA and between γ-HCH and PC in AD patients. These findings showed that pesticide exposure is associated with an increased risk of AD. Furthermore, the mean levels of oxidative stress markers, which may result from pesticide exposure, were significantly lower in AD patients compared to healthy individuals.

CONCLUSION

Therefore, it may conclude that pesticides, at least in part, contribute to AD development through several mechanisms, including the induction of oxidative stress.

Persistent organochlorine pesticides in periprostatic adipose tissue from men with prostate cancer: Ethno-geographic variations, association with disease aggressiveness

Although several studies have examined the relationship between organochlorine pesticides (OCPs) and prostate cancer (PCa) risk, no data are available concerning the association between OCPs concentrations in periprostatic adipose tissue (PPAT), which reflects cumulative exposure, and PCa aggressiveness. Moreover, no previous study has compared OCPs exposure in two distinct ethno-geographical populations. The objectives were to analyze OCPs in PPAT of PCa patients from either Mainland France or French West Indies in correlation with features of tumor aggressiveness, after adjusting for potential confounders such age, BMI, and polyunsaturated fatty acid (PUFA) content of PPAT. PPAT was analyzed in 160 patients (110 Caucasians and 50 African-Caribbeans), 80 with an indolent tumor (ISUP group 1 + pT2), and 80 with an aggressive tumor (ISUP group more than 3 + pT3). The concentrations of 29 OCPs were measured in PPAT concomitantly with the characterization of PUFA content. Exposure patterns of OCPs differed according to the ethno-geographical origin. Most OCPs were found at higher concentration in Caucasian patients, whereas pp'-DDE content was twice as high in African-Caribbeans. Chlordecone was only detected in PPAT from African-Caribbean patients. Most OCP concentrations were positively correlated with age, and some with BMI. After adjusting for age, BMI, and PUFA composition of PPAT, no significant association was found between OCPs content and risk of aggressive disease, except of mirex which appeared inversely associated with aggressive features of PCa in Caucasian patients. These results highlight a significant ethno-geographic variation in internal exposure to OCPs, which likely reflects differences in consumption patterns. The inverse relationship observed between mirex concentration and markers of PCa aggressiveness need to be further investigated.

Evaluating the fate and potential health risks of organochlorine pesticides and triclosan in soil, sediment, and water from Asa Dam River, Ilorin Kwara State, Nigeria

The quest for safe water due to exponential population growth and climate change has stressed the existing available water source. It is crucial to establish the present pollution level of the Asa River and the health risk it may pose to the people. Samples were collected along the Asa River, Ilorin, Kwara State, Nigeria, and treated using standard methods as stipulated by United States Environmental Protection Agency. The treated samples were analyzed and quantified for dieldrin, endrin, dichlorodiphenyltrichloroethane metabolites, mirex, hexachlorocyclohexane, hexachlorobenzene, and triclosan using the gas chromatography-mass spectrometry. The result showed that the levels of organochlorine pesticides (OCPs) ranged from 0.0045-0.947 μg/kg, 0.0036-0.093 μg/kg, and 0.001-0.007 μg/L in sediment, soil, and water samples, respectively. While the mean concentration of triclosan is 3.78 μg/kg, 2.995 μg/kg, and 0.064 μg/L in sediment, soil, and water samples, respectively. The levels of OCPs were lower than the limits in drinking water as set by World Health Organization and European Union. Health risk assessment for both children and adults was evaluated using non-carcinogenic and carcinogenic risk with the hazard quotient (HQ) and was found to be greater than unity (> 1) in children for the targeted OCPs. Associated cancer risk for OCPs ranged from low cancer risk to moderate risk for humans. The adverse ecological effects of OCPs showed to be very rare to occur and frequent effects may not likely occur except for HCH.

Monitoring and risk assessment of exposure to organochlorine pesticides through the water supply system, case of Karkheh River in southwest Iran

In this investigation, the concentration of some organochlorine pesticides (OCPs) was monitored in the Karkheh River and the risk assessment of exposure to these pesticides residue through the water supply system was calculated. The mean concentrations of Lindane, Heptachlor, Chlordane, Dieldrin, Endrin, DDT were 0.135, 0.123, 0.077, 0.081, 0.076, 0.01 µg/L, respectively. The average risk of Lindane, Heptachlor, Chlordane, Dieldrin, DDT, and Endrin for adults was 1.2 E-6, 1.1E-6, 7E-7, 7.6E-7, 9E-8, 7E-7 or non-carcinogenic risks to adults decreased in Dieldrin > Chlordane > Heptachlor > Endrine > DDT > lindane. The hazard index for all organochlorine pesticides was less than 1. These results did not raise concerns about the health of people exposed to studied pesticides. Total concentrations of all OCPs in the Karkheh River were below guidelines for individual pesticides. The hazard quotient showed that the consumption of treated water from the Susangard drinking water treatment plant has no non-cancerous effects. The HI was less than 1 that indicating the risk of exposure to a mixture of OCPs was not significant. Developing policies to reduce the use of pesticides and the use of suitable management practices could be implemented to lower the pesticide levels in the Karkheh River.

Ecological risk assessment of organochlorine pesticide mixture in South China Sea and East China Sea under the effects of seasonal changes and phase-partitioning

Organochlorine pesticides (OCPs), chlorinated hydrocarbon derivatives extensively used in agriculture and chemical industry, have been banned for several decades in most developed countries. However, OCPs act as persistent organic pollutants due to their semi-volatility nature, high ability for wide range transportation and faster bioaccumulation, and thus it has remained as a topical global concern. This study focuses on OCP distributions, sources and associated ecological risks in the globally important OCP source-sink regions of South China Sea (SCS) and East China Sea (ECS). Given the co-exposure of multiple OCPs that undermine the classical risk assessment of single OCP species, a two-tier mixture risk assessment approach has been employed with explicit consideration of seasonal changes and phase-partitioning effects. The results indicate existence of multiple sources varied across the seasons and between the dissolved and particulate phases. Potential sources include the current-use of lindane or historical use of technical HCH, input of technical DDTs, long-range atmospheric transport, and deposition of HCB from land surfaces. There are no wide high-risk zones. Dissolved HCB and DDTs have posed low-to-medium levels of risks broadly distributed across the seasons. Relatively greater risks are observed in summer in the both dissolved and particulate phases. The study has shown the importance of considering mixture risk assessments with the effects of phase-partitioning and seasonal changes for efficient oceanic risk management.

Distribution characteristics, sources, and risk assessment of organochlorine pesticides in the Fildes Peninsula and Adelaide Island

This work analyzed the distribution characteristics, sources, and corresponding environmental risks of 10 organochlorine pollutants (OCPs) in soil samples from 13 stations on the Fildes Peninsula and Adelaide Island in Antarctica in 2020. Results showed that the total amount of OCP residues in the study area ranged from N.D. to 2.66 ng·g^-1 with an average concentration of 0.90 ng·g^-1. Six organochlorine pesticides were detected, and the residue level of DDTs was slightly lower than that of HCHs. The residues of HCHs were mainly γ-HCH and those of DDTs were mainly O, P'-DDT. Source analysis revealed that the residues mainly originated from atmospheric transport and human activities. Environmental risk analysis showed that in the study area, the residues of HCHs and DDTs were present at low levels, and their ecological risk was low.

Non-corresponding contaminants in marine surface sediments as a factor of ARGs spread in the Sea of Azov

The present study aims to analyze the level and total toxicity of the most common pollutants in surface sediments and assess their impact on the occurrence of antibiotic resistance genes (ARGs) in the Sea of Azov. Biotesting using the whole-cell bacterial lux-biosensors showed high integral toxicity of surface sediments and the presence of genotoxicants and substances that cause oxidative stress and protein damage. Using cluster analysis, it was shown that the distribution of pollutants in the Sea of Azov depends on the type of surface sediments. The relative abundance and distribution of 14 ARGs in surface sediments were shown. Principle component analyses results suggest that non-corresponding contaminants do not exert direct influence on the ARGs abundance in the surface sediments of the Sea of Azov. Thus, the need to investigate the significance of non-corresponding pollutants in the selection and distribution of ARGs in the aquatic environment remains a pressing problem.

Public healthcare costs associated with long-term exposure to mixtures of persistent organic pollutants in two areas of Southern Spain: A longitudinal analysis

BACKGROUND

Polychlorinated biphenyls and organochlorine pesticides are persistent organic pollutants (POPs) that had been banned or restricted in many countries, including Spain. However, their ubiquity still poses environmental and human health threats.

OBJECTIVE

To longitudinally explore public healthcare costs associated with long-term exposure to a mixture of 8 POPs in a cohort of residents of two areas of Granada Province, Southern Spain.

METHODS

Longitudinal study in a subsample (n = 385) of GraMo adult cohort. Exposure assessment was performed by analyzing adipose tissue POP concentrations at recruitment. Average primary care (APC) and average hospital care (AHC) expenditures of each participant over 14 years were estimated using the data from their medical records. Data analyses were performed by robust MM regression, weighted quantile sum regression (WQS) and G-computation analysis.

RESULTS

In the adjusted robust MM models for APC, most POPs showed positive beta coefficients, being Hexachlorobenzene (HCB) significantly associated (β: 1.87; 95% Confidence interval (95%CI): 0.17, 3.57). The magnitude of this association increased (β: 3.72; 95%CI: 0.80, 6.64) when the analyses were restricted to semi-rural residents, where β-HCH was also marginally-significantly associated to APC (β: 3.40; 95%CI: -0.10, 6.90). WQS revealed a positive but non-significant mixture association with APC (β: 0.14; 95%CI: -0.06, 0.34), mainly accounted for by β-HCH (54%) and HCB (43%), that was borderline-significant in the semi-rural residents (β: 0.23; 95%CI: -0.01, 0.48). No significant results were observed in G-Computation analyses.

CONCLUSION

Long-term exposure to POP mixtures might represent a modifiable factor increasing healthcare costs, thus affecting the efficiency of the healthcare systems. However, and owing the complexity of the potential causal pathways and the limitations of the present study, further research is warranted to fully elucidate ascertain whether interventions to reduce human exposure should be considered in healthcare policies.

The European Chub (Squalius cephalus) as an indicator of reservoirs pollution and human health risk assessment associated with its consumption

Five reservoirs (Vlasina, Medjuvršje, Zaovine, Perućac, and Garaši) in Serbia were chosen as study sites, which differ by their position, purpose, stages of eutrophication, management policies, and levels of anthropogenic pressure. The objectives of this research were to: determine the concentrations of 26 elements in muscle, gills, and liver of the European chub by inductively-coupled plasma optical emission spectrometry (ICP-OES); determine the concentrations of 17 organochlorine pesticides in fish muscle by gas chromatography with mass spectrometric detection (GC-MS); compare these findings with condition factor (CF) and histopathological (HP) biomarkers; and assess the potential human health risks due to consumption of chub muscle tissue. The highest elemental accumulation was found in the gills. The European chub was not a good indicator of Pb pollution between reservoirs. Concentrations of Hg, As, and Cu were low and did not exceed the proscribed maximum allowed concentrations (MACs). 4,4'-DDE was detected only in individuals from Vlasina, 4,4'-DDD from Perućac and Zaovine, and heptachlor from Zaovine. Low to moderate levels of HP were observed for both gills and liver in all studied reservoirs. HP index for gills was significantly higher for Zaovine compared to Vlasina. Significantly lower HP index for liver and the total HP index value were observed for fish from Vlasina compared to Perućac. No significant human health risks due to the intake of examined pollutants in each reservoir were recorded; women were at higher risk compared to men. A reason for concern is a few muscle samples from Garaši, Vlasina, Perućac, and Medjuvršje in which Cd exceeded the MAC. A reservoir for water supply (Garaši) is generally considered the safest for fish consumption.

Novel N-riched covalent organic framework for solid-phase microextraction of organochlorine pesticides in vegetable and fruit samples

A covalent organic framework named N-COF was successfully constructed by the aldehyde-amine condensation reaction between 2,4,6-tris (4-formyl phenoxy)-1,3,5-triazine and 1,3-bis(4-aminophenyl) urea for the first time. The prepared N-COF exhibited good stability and high affinity to organochlorine pesticides (OCPs). Thus, the N-COF was served as solid phase microextraction fiber coating for extraction of six OCPs from vegetables and fruits including romaine lettuce, cabbage, Chinese cabbage, apple, pear and peach, followed by quantitation with gas chromatography-electron capture detector (GC-ECD). Under the optimal conditions, good linearities for the OCPs existed in the ranges from 0.1 to 1.0 ng g^-1 to 100.0 ng g^-1 for the samples. The low limits of detection for analytes were obtained in the range of 0.03-0.3 ng g^-1. The present work can offer new alternative for sensitive analysis of trace level of OCPs in vegetables and fruits.

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

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

Legacy and new chlorinated persistent organic pollutants in the rivers of south India: Occurrences, sources, variations before and after the outbreak of the COVID-19 pandemic

During pre-pandemic time, organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) were investigated in the surface water of Periyar River (PR) and Bharathappuzha River (BR) in Ernakulam and Malappuram districts of Kerala, respectively and Adyar River (AR) and Cooum River (CR) in Chennai district of Tamil Nadu. After the outbreak of COVID-19 pandemic, variation in OCPs and PCBs were evaluated for AR and CR. Dominance of β-HCH and γ-HCH in south Indian rivers indicate historical use of technical HCH and ongoing use of Lindane, respectively. In > 90 % sites, p,p'-DDT/ p,p'-DDE ratio was < 1, indicating past DDT usage. However during the outbreak of the COVID-19 pandemic, elevated p,p'-DDT in AR and CR reflects localized use of DDT possibly for vector control. Similarly, during the first wave of pandemic, over a 100-fold increase in PCB-52 in these rivers of Chennai mostly via surface run-off and atmospheric deposition can be reasoned with open burning of dumped waste including added waste plastic in the solid waste stream. On contrary, a significant (p < 0.05) decline of dioxin-like PCBs level, suggests lesser combustion related activities by the formal and informal industrial sectors after the lockdown phase in Tamil Nadu. Eco-toxicological risk assessment indicated a higher risk for edible fish in PR due to endosulfan.

A First Record of Organochlorine Pesticides in Barn Owls (Tyto alba) from Portugal: Assessing Trends from Variation in Feather and Liver Concentrations

We evaluated feathers as a non-destructive biomonitoring tool documenting organochlorine pesticides (OCP) in liver and checked possible trends in pesticide use in two areas based on OCP concentrations in barn owls (Tyto alba). We measured the concentrations of 16 OCP in 15 primary feathers and 15 livers from barn owl carcasses collected on roadsides in Tagus Valley and Évora regions, south Portugal. Total OCP mean concentration was 8 120 ng g^-1 in feathers and 178 ng g^-1 in livers. All compounds were detected in feathers while in livers δ-HCH, endosulfan sulphate, p,p'-DDT and p,p'-DDD were not detected. The high β-HCH and heptachlor concentrations in feathers most likely derived from external endogenous contamination. P,p'-DDE was the OCP with the highest hepatic concentration. Both matrices indicated an exposure to recently released heptachlor. The differing OCP concentrations between Tagus Valley and Évora seem to reflect differences in land-use and pesticide use histories of the two locations, and/or faster degradation of OCP in the Tagus area.

Organochlorine pesticide exposures, metabolic enzyme genetic polymorphisms and semen quality parameters among men attending an infertility clinic

The associations of organochlorine pesticides (OCPs) with semen quality from human studies are conflicting, and also it is largely unknown whether the associations are modified by genetic polymorphisms. We aimed to evaluate the associations between serum concentrations of 18 OCPs and semen quality among 387 Chinese men, and further to examine the modifying effects by genetic polymorphisms in cytochrome P450 (CYP2E1) and glutathione S-transferase (GSTT1). Multivariable linear regressions were used to evaluate the relationships between serum OCP concentrations and semen quality, and the role of CYP2E1 and GSTT1 polymorphisms in modifying the associations were assessed. Multiple testing was adjusted using the false discovery rate (FDR). We observed that men with detectable concentrations of serum ɤ-HCH had a decrease in sperm motility of 7.07% (95% CI: -10.9%, -3.24%) compared to those with undetectable concentrations (FDR-P value = 0.02). Men with TT of CYP2E1 rs 915906 genotypes had higher median concentrations of serum dieldrin compared with those with CT/CC of CYP2E1 rs 915906 genotypes. There were interactions between CYP2E1 and GSTT1 polymorphisms and certain OCPs namely ɤ-HCH, δ-HCH, dieldrin, endosulfan I, and endrin aldehyde on semen quality. For example, elevated dieldrin levels in relation to decreased sperm concentration, sperm count, and sperm motility were only observed among men with CC of CYP2E1 rs2031920 genotypes (all P_interaction < 0.05). However, these interactions were not statistically significant after the FDR adjustment. Our results suggested that CYP2E1 and GSTT1 polymorphisms may modify the effects of OCP exposures on semen quality. Due to the relatively small size samples, further investigation is warranted to confirm the findings.

Horizontal planetary mechanochemical method for rapid and efficient remediation of high-concentration lindane-contaminated soils in an alkaline environment

Lindane is a persistent organic pollutant that has attracted worldwide attention because of its threat to human health and environmental security. A horizontal planetary mechanochemical method was developed for rapid and efficient degradation of lindane in soil in an alkaline environment. Under the condition of a very low reagent-to-soil ratio (R = 2%), ball-to-powder ratio (C_R = 6:1), rotation speed (r = 300 rpm) and high soil single treatment capacity (S_C = 60 g), the lindane in four typical soils (~ 100 mg/kg) can be degraded up to 96.30% in 10 min. This method can also remediate high-concentration lindane-contaminated soil (833 ± 26 mg/kg). The experimental results and theoretical calculations proved that the stepwise dechlorination and final carbonization of lindane in soil are mainly attributed to the combined action of mechanical energy and alkalinity. The bimolecular elimination (E2) reaction was the first step of lindane destruction. Subsequently, the unimolecular elimination (E1) reaction tended to occur with the weakening of alkalinity. Then, benzene was obtained through stepwise hydrogenolysis reaction. The last was the generation of carbon substances by fragmentation or condensation of benzene rings. This work proposes a practical remediation technology for organic contaminated soil and improves the understanding of the degradation pathways of lindane in soil in alkali-assisted mechanochemical system.

Pilot study on the concentrations of organochlorine compounds and potentially toxic elements in pregnant women and local food items from the Finnish Lapland

In the Arctic, main sources of persistent organic pollutants and potentially toxic elements are industry and agriculture in the lower latitudes. However, there are also local sources of pollution. Our study was focused on possible pollution in the Finnish Lapland, transferred from the Pechenganikel industrial complex located in the borders of Russia, Finland and Norway. Local food items and blood samples of pregnant women from the Inari municipality were collected and organochlorine compounds (OCs) and metal(oid)s analyzed. Most of the examined food samples showed detectable levels of these compounds. The mean concentrations of DDTs and polychlorobiphenyls (PCBs) were higher in fish (0.18-0.32 ng/g and 0.34-0.64 ng/g, respectively), than in the other food groups (0.027-0.047 ng/g and 0.11-0.20 ng/g, respectively). PCBs were found at the highest concentrations in blood samples of the pregnant women, and congeners 153 and 118 were dominant. The mean concentration of PCB153, 0.29 μg/kg serum lipid, was lower than those described in many other studies. Concerning DDTs, the 4,4'-DDT/4,4'-DDE ratio, 0.092, in the blood samples was lower than that observed in the food items, 0.25-0.71, reflecting old uses of the DDT pesticide. None of the observed levels of selected potentially toxic elements in blood samples and in food items exceeded the known safe limits. Higher concentrations of PCB52 and γ-HCH were observed in the serum of pregnant women who consumed greater amounts of meat, and berries and mushrooms, respectively. The OC concentrations from the pregnant women currently studied were lower than those observed fourteen years ago with pregnant women from the same municipality. Compounds whose occurrence is likely related to a long-distance transport showed clear decreases, e.g., 63% for PCBs, and for those from pesticides, decreases were 93% and 97% for 4,4'-DDE and β-HCH, respectively. No obvious influence from the Pechenganikel complex is observed from the results.

Distribution characteristics, source analysis and risk assessment of organochlorine pesticides in Ny-Ålesund, Arctic

The distribution characteristics, sources, and risk levels of organochlorine pesticides (OCPs) in Ny-Ålesund of the Arctic region during China's 10th Arctic expedition were studied in this paper. Results showed that the concentration of OCPs in the surface soil of the Ny-Ålesund region ranged from 0.59 ng·g^-1 to 3.87 ng·g^-1, with an average concentration of 2.22 ng·g^-1. Source analysis showed that the OCPs in the study area mainly originated from historical residues, and a certain degree of conversion between congeners of hexachlorocyclohexanes and dichlorodiphenyltrichloroethanes in the soil occurred due to environmental factors. Ecological risk assessment indicated that the study area was at a low ecological risk level, but the potential environmental impact of OCPs could not be neglected due to the specificity and sensitivity of the Arctic environment.

Spatiotemporal evaluation of organochlorine pesticide residues in bottom sediments of the Rio de Ondas hydrographic basin, western Bahia, Brazil

The Rio de Ondas Hydrographic Basin (ROHB), Bahia state, Brazil, is located in a region with abundant water resources and is highly impacted by intense agricultural activity. In such a scenario, the use of organochlorine pesticides can represent a potential risk to the aquatic environments, due to their persistence, high bioaccumulation capacity, and high toxicity. Thus, organochlorine pesticide residues in bottom sediment samples from rivers on eighteen sites distributed along the ROHB in the dry and rainy periods were analyzed by gas chromatography coupled with mass spectrometry. The validated method showed no matrix effect, recoveries ranging from 82% (β-HCB) to 118% (DDD), limits of detection between 0.003 ng g^-1 (α-HCH) and 0.011 ng g^-1 (DDT), limits of quantification of 0.010 ng g^-1 (α-HCH) to 0.036 ng g^-1 (DDT), repeatability with the highest relative standard deviation of 0.97% (α-hexachlorocyclohexane at 2.000 ng g^-1), and inter-day precision ranging from 10% (aldrin at 0.050 ng g^-1 and 0.600 ng g^-1 and α-endosulfan at 0.600 ng g^-1) to 25% (β-endosulfan at 0.050 ng g^-1). Although most compounds were banned since 1985, it was observed that their residues were widely distributed in the ROHB, with the total concentrations varying from 3.242 ng g^-1 (P02) to 12.052 ng g^-1 (P17) and from 0.313 ng g^-1 (P14) to 30.861 ng g^-1 (P13) in the dry and rainy periods, respectively, which may be related to historical contamination and/or prohibited use. Moreover, the spatiotemporal variation showed the highest concentrations of organochlorine pesticide residues in the rainy season, coinciding with the planting period.

Serum multiple organochlorine pesticides in relation to testosterone concentrations among Chinese men from an infertility clinic

BACKGROUND

Organochlorine pesticides (OCPs) are endocrine-disrupting chemicals and may alter male reproductive hormone concentrations.

OBJECTIVE

To explore the associations between multiple OCP exposures and serum testosterone concentrations among Chinese men.

METHODS

We investigated 421 men who provided serum samples from an infertility clinic in Wuhan, China. Each man completed a questionnaire concerning demographic characteristics and lifestyle habits. Serum concentrations of 18 OCPs and total testosterone were measured. Linear regression models were used to explore whether serum OCP levels were associated with altered testosterone concentrations, and potential effect modifications by age and body mass index (BMI) were also examined.

RESULTS

After adjusting for potential confounders, elevated dieldrin and p,p'-DDD levels had monotonically negative and positive exposure-response associations with testosterone concentrations, respectively (-30.98 ng/dL, 95% CI: -72.34, 10.37; P for trend = 0.12 and 41.31 ng/dL, 95% CI: -0.32, 82.93; P for trend = 0.06 for the highest vs. non-detectable exposure category, respectively). After stratification by age and BMI, dieldrin in relation to decreased testosterone concentrations was more pronounced among men aged <30 years old, and p,p'-DDD in relation to increased testosterone concentrations was stronger among men aged ≥30 years old and among men with a BMI <24 kg/m², though the differences were not statistically significant.

CONCLUSION

The study found evidence that serum dieldrin and p,p'-DDD concentrations might be associated with altered serum testosterone concentrations.

Health risk assessment of pesticide residue in freshly harvested Vigna subterranea (Bambara nut) in Nsukka South Eastern Nigeria

Two species of freshly harvested Bambara nut were analyzed for organophosphate and organochlorine pesticide residue using GC-FID and GC-ECD. The risk associated with the consumption of the Bambara nut was evaluated using the health risk index (HRI) and the probable cancer risk (PCR). A maximum of thirteen (13) organochlorines and eight (8) organophosphate pesticides were determined from both species respectively. The results revealed that almost all the quantified pesticides exceeded their respective FAO maximum residue levels (MRLs). The health risk index (HRI) values of the organochlorines and organophosphates were below 1 in adults indicating little or no risk to adults. While the HRI of the organophosphates and a few values in the organochlorines were above 1 in children indicating that organophosphate pesticides in the freshly harvested white and mixed Bambara nut could pose a great health risk to children within these areas. The Hierarchical Cluster Dendrogram indicated similar sources of the assessed organochlorine and organophosphate pesticides.