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This paper introduces a novel and minimized sample preparation technique based on hollow fiber-protected liquid-phase microextraction that can be used in joint with gas chromatography-mass spectrometry (GC-MS) detection to extract three organochlorine pesticides—Endrin, Chlordane, and Dieldrin—from rice samples. To that end, a single-walled carbon nanotube (SWCNT) and a proper ionic liquid (IL) were ultrasonically dispersed and injected into the lumen of hollow fiber as the extraction phase for preconcentrating and extracting the target analytes from the rice samples. The effects of the type of nanoparticles, ILs, and desorption solvent on the efficiency of extracting the analytes were investigated based on the one-factor-at-a-time (OFAT) approach. In addition, other parameters influencing the extraction procedure were optimized using an experimental design that decreased the number of experiments, reagent consumption, and costs. Under optimized conditions, the limits of detection and quantification in determining mentioned pesticides varied between 0.019–0.029 and 0.064–0.098 ng mL−1, respectively. The calibration graphs to measure Endrin, Chlordane, and Dieldrin were linear over the concentration range of 0.064–13.2, 0.098–16.7, and 0.092–11.4 ng mL−1, respectively. The relative standard deviations for inter-day and intra-day analysis were below 7.06 and 4.75% for the triplicate determination of three organochlorine pesticides. Besides, the relative recoveries and standard deviations of Endrin, Chlordane, and Dieldrin for analyzing several Iranian rice samples were between 86.0–92.9% and 4.5–5.8%, respectively. The results were compared with other similar works in literature, proving that the proposed method is efficient and useful for routine monitoring of organochlorine compounds in food samples. [ABSTRACT FROM AUTHOR]

The Navachiste complex (NAV) is impacted by neighbored human activities and is located in the southwestern coastal zone of the Gulf of California. The study determines the trace metal (TM) and organochlorine pesticides (OCP) health risk content in the edible tissue of Sphoeroides spp. from NAV. The daily intakes (EDI), target hazard quotient (THQ), hazard index (HI), and carcinogenic and non-carcinogenic risks were calculated. Twenty OCP and seven TM were detected. Cd, Cu, Fe, Mn, Pb, and Zn were above MRLs. The γ‒Chlordane was the most frequent OCP. The highest average concentration was for α‒HCH, followed by γ‒chlordane. With the high ratios of γ‒HCH, p, p′‒ DDD and p, p′‒DDD, and the absence of p, p′‒ DDT, the higher ratios for dieldrin and endrin than for aldrin, α‒ chlordane, γ‒chlordane, heptachlor, and heptachlor epoxide indicates historical contamination. In contrast, the residual products of methoxychlor, endosulfan, and its isomers indicate endosulfan's recent use. The TM EDI, THQ > 1 (at 120 g day−1), and the ILCR (> 1 × 10–6) were above minimum levels, showing a high-risk potential for cancer development in the long term. [ABSTRACT FROM AUTHOR]

This study evaluated the concentrations of organochlorine pesticides (OCPs) in inlet and outlet of treatment plant of Ahvaz city. For this purpose, the concentrations of six OCPs, including chlordane, dieldrin, dichlorodiphenyltrichloroethane, heptachlor, lindane, and endrin were measured at three different sites during, 12 months. A gas chromatograph-mass spectrometer (GC-MS) device was applied for the analysis and determination of the target pesticides in the water samples. Non-carcinogenic risk analysis showed that total hazard index was below the acceptable limit and there was no danger to the residents of the area, and the carcinogenic risk was within the acceptable range for both the groups of children and adults. The results implied that the concentrations of the studied pesticides decreased after treatment process. The concentrations of the pesticides were lower than the standard level in all seasons. In the chlorination units (water treatment plants No. 1 and 2) of the treatment plant, the concentrations of OCPs were decreased in winter, while the concentration of these compounds in river water was quite high in summer. The mean total concentration of OCPs in the water samples in August, September, October, November, December, January, February, March, April, May, June, and July were 0.3, 0.073, 0.046, 0.033,0.01, 0.03, 0.025, 0.026, 0.025, 0.03, 0.21, and 0.04 µg/L, respectively. [ABSTRACT FROM AUTHOR]

The present study has been oriented to the integrated assessment of physical, chemical, and physicochemical characteristics of the agricultural runoff (AR). The physical growth vigor, physiological and morphological changes, oxidative stress biomarkers, enzymatic and non-enzymatic antioxidative responses, elemental profiles, and bioaccumulative pathway of okra plant in relation to the changing concentrations of AR-induced irrigation were evaluated using a soilless cultivation system. Lindane, endosulfan, heptachlor epoxide, methoxychlor, hexachlorobenzene, chlordane, aldrin, heptachlor, dichlorodiphenyl-trichloroethane, and dieldrin were predominantly detected within the concentration range of 0.0025-0.069 µg/L, while arsenic, boron, copper, iron, manganese, and zinc were found at 0.63-25.50 µg/L Concentration-dependent alterations of macroscopic symptoms, chlorophylls, morphological structures, reactive oxygen species, lipid peroxidation, protein oxidation, antioxidant enzymes, total phenolic content, and radical scavenging potential were recorded in the AR-irrigated groups. The accumulation of heavy metals were found in a descending order of: root > shoot > leaf > fruit. Specifically, arsenic was identified as the critical polluting species, as evidenced by the drastic interference in the uptake and metabolism of phosphate, calcium, potassium, and magnesium. The tolerable threshold concentration of 60% AR could be applied as a renewable source of irrigation water, verified by the negligible phytotoxic implications in the plant model. [ABSTRACT FROM AUTHOR]

The present study has been oriented to the integrated assessment of physical, chemical, and physicochemical characteristics of the agricultural runoff (AR). The physical growth vigor, physiological and morphological changes, oxidative stress biomarkers, enzymatic and non-enzymatic antioxidative responses, elemental profiles, and bioaccumulative pathway of okra plant in relation to the changing concentrations of AR-induced irrigation were evaluated using a soilless cultivation system. Lindane, endosulfan, heptachlor epoxide, methoxychlor, hexachlorobenzene, chlordane, aldrin, heptachlor, dichlorodiphenyl-trichloroethane, and dieldrin were predominantly detected within the concentration range of 0.0025–0.069 µg/L, while arsenic, boron, copper, iron, manganese, and zinc were found at 0.63–25.50 µg/L. Concentration-dependent alterations of macroscopic symptoms, chlorophylls, morphological structures, reactive oxygen species, lipid peroxidation, protein oxidation, antioxidant enzymes, total phenolic content, and radical scavenging potential were recorded in the AR-irrigated groups. The accumulation of heavy metals were found in a descending order of: root>shoot>leaf>fruit. Specifically, arsenic was identified as the critical polluting species, as evidenced by the drastic interference in the uptake and metabolism of phosphate, calcium, potassium, and magnesium. The tolerable threshold concentration of 60% AR could be applied as a renewable source of irrigation water, verified by the negligible phytotoxic implications in the plant model. [Display omitted] [ABSTRACT FROM AUTHOR]

Chlordane compounds (CHLs) are components of technical chlordane listed in the Stockholm convention on persistent organic pollutants identified as endocrine disrupting chemicals (EDCs) and may interfere with hormone biosynthesis, metabolism or action resulting in an unbalanced hormonal function. There is increasing scientific evidence showing EDCs as risk factors in the pathogenesis and development of obesity and obesity-related metabolic syndromes such as type 2 diabetes, but there is no systematized information on the effect of CHLs in humans. Our aim is to identify the epidemiological data on the association between CHLs with adiposity and diabetes using a systematic approach to identify the available data and summarizing the results through meta-analysis. We searched PubMed and Web of Science from inception up to 15 February 2021, to retrieve original data on the association between chlordanes, and adiposity or diabetes. For adiposity, regression coefficients and Pearson or Spearman correlation coefficients were extracted and converted into standardized regression coefficients. Data were combined using fixed effects meta-analyses to compute summary regression coefficients and corresponding 95% confidence intervals (95% CI). For the association between chlordanes and diabetes, Odds ratios (ORs) were extracted and the DerSimonian and Laird method was used to compute summary estimates and respective 95% CI. For both, adjusted estimates were preferred, whenever available. Among 31 eligible studies, mostly using a cross-sectional approach, the meta-analysis for adiposity was possible only for oxychlordane and transchlordane, none of them were significantly associated with adiposity [(β = 0.04, 95% CI 0.00; 0.07, I2 = 89.7%)] and (β = 0.02, 95% CI − 0.01; 0.06), respectively. For diabetes, the estimates were positive for all compounds but statistically significant for oxychlordane [OR = 1.96 (95% CI 1.19; 3.23)]; for trans-nonachlor [OR = 2.43 (95% CI 1.64; 3.62)] and for heptachlor epoxide [OR = 1.88 (95% CI 1.42; 2.49)]. Our results support that among adults, the odds of having diabetes significantly increase with increasing levels of chlordanes. The data did not allow to reach a clear conclusion regarding the association with adiposity. [ABSTRACT FROM AUTHOR]

Organochlorine pesticides (OCPs) have been used globally to boost food production. Although banned, due to their prolonged toxic effects but their residue still impacts the quality of primary and processed agricultural products. This study assesses the levels of residual OCPs (α,β,δ-HCH, heptachlor, heptachlor epoxide, chlordane, methoxychlor, aldrin, dieldrin, endrin, endrin aldehyde, endrin ketone, endosulfan, endosulfan sulfate, 1,1-dichloro-2,2-bis(p-chlorophenyl)ethane (DDD), 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE), and 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT)) in food commonly consumed in Lagos and Ibadan, Southwest, Nigeria. Health risk associated with human exposure via food intake was evaluated with a statistical predictive model. About 248 composite food samples from 8 categories were analyzed in Lagos and Ibadan. Sample extraction and clean-up were by QueChERS method and extracts injected into GC-μECD. ƩDDT concentration was highest in meat products, aquatic foods, dairy products, edible oils, fruits, and cereals, while ƩHCHs were highest in chicken eggs and vegetables. ƩOCP concentrations (ng/g) in food categories were 6.09±1.6–6.85±0.9 (meat), 5.29±2.0–12.3±14 (aquatic foods), 4.86±1.7–5.89±0.8 (dairy products), 4.53±0.8–6.32±1.1 (edible oils), 3.32±1.3 (eggs), 3.54±1.0–4.80±1.5 (fruits), 4.16±2.7–4.40±0.8 (vegetables), and 6.12±2.0–6.62±0.9 (cereals). The estimated average daily intake of OCPs was 5.91, 12.5, 4.41, 6.40, 1.53, 5.14, 3.95, and 16.7 ng/kg bw/day through the consumption of meat products, aquatic foods, dairy products, edible oils, chicken eggs, fruits, vegetables, and cereals, respectively. The health risk of residual OCPs via ingestion of foods considered in this study was <1, which implied no potential health risk at the current consumption rate. However, regular monitoring of OCPs residues in food is highly recommended. Finally, the method scaled the analytical Eco-Scale evaluation and Green Analytical Chemical Procedure Index as "an acceptable green analysis method." [ABSTRACT FROM AUTHOR]

This preliminary investigation highlights the occurrence of organochlorine pesticides (OCPs) in the indoor environment of a megacity, Lahore, Pakistan using the dust ensnared by air‐conditioner filters. The Σ16OCPs concentration ranged from 7.53 to 1272.87 ng/g with the highest percent contribution by ΣDDT (dichlorodiphenyltrichloroethane; 87.21%) and aldrin (6.58%). The spatial variation of OCPs profile revealed relatively higher concentration from homes near to agricultural and abandoned DDT manufacturing sites. Calculated isomer ratios revealed historic sources of hexachlorocyclohexanes (HCHs) and the fresh input of technical DDT and chlordane by the dwellers. The air conditioner dust was helpful to better understand the health risk in the indoor environment. So far a high lifetime cancer risk (10−3) was predicted for toddlers via accidental ingestion, inhalation, and dermal exposure. Similarly, the non‐carcinogenic risk‐based hazard quotient was found to be high for toddlers (6.94) and within the permissible limit (<1) for adults. [ABSTRACT FROM AUTHOR]

Insecticide use has been linked to increased risk of non‐Hodgkin lymphoma (NHL), however, findings of epidemiologic studies have been inconsistent, particularly for NHL subtypes. We analyzed 1690 NHL cases and 5131 controls in the North American Pooled Project (NAPP) to investigate self‐reported insecticide use and risk of NHL overall and by subtypes: follicular lymphoma (FL), diffuse large B‐cell lymphoma (DLBCL) and small lymphocytic lymphoma (SLL). Odds ratios (OR) and 95% confidence intervals for each insecticide were estimated using logistic regression. Subtype‐specific associations were evaluated using ASSET (Association analysis for SubSETs). Increased risks of multiple NHL subtypes were observed for lindane (OR = 1.60, 1.20‐2.10: FL, DLCBL, SLL), chlordane (OR = 1.59, 1.17‐2.16: FL, SLL) and DDT (OR = 1.36, 1.06‐1.73: DLBCL, SLL). Positive trends were observed, within the subsets with identified associations, for increasing categories of exposure duration for lindane (Ptrend = 1.7 × 10−4), chlordane (Ptrend = 1.0 × 10−3) and DDT (Ptrend = 4.2 × 10−3), however, the exposure‐response relationship was nonlinear. Ever use of pyrethrum was associated with an increased risk of FL (OR = 3.65, 1.45‐9.15), and the relationship with duration of use appeared monotonic (OR for >10 years: OR = 5.38, 1.75‐16.53; Ptrend = 3.6 × 10−3). Our analysis identified several novel associations between insecticide use and specific NHL subtypes, suggesting possible etiologic heterogeneity in the context of pesticide exposure. What's new? Insecticides are persistent environmental pollutants that have been linked to increased risk of non‐Hodgkin lymphoma (NHL). Although NHL encompasses a heterogeneous group of malignancies, few studies have examined subtype‐specific associations for insecticide exposure. Analyzing data from population‐based case‐control studies of lymphatic cancers, the authors of this study show that lindane, chlordane, and DDT are associated with increased risk of multiple NHL subtypes. Analyses further uncovered a novel link between increased follicular lymphoma risk and pyrethrum use. None of the insecticides investigated, however, were associated with all NHL subtypes, suggesting a role for etiologic heterogeneity in pesticide exposure and NHL risk. [ABSTRACT FROM AUTHOR]

The objective of this study was to identify and evaluate the impact of exposure to mixtures of organochloride pesticides (OCPs) in agricultural workers by detecting their effects on the activity of the enzyme glutathione S-transferase (GST) and the presence of polymorphisms of the GSTT1 and GSTM1 genes. The presence of OCPs was identified and quantified by gas chromatography, while spectrophotometry was used to measure enzymatic GST activity. The frequencies of the GSTM1 genotypes were analyzed by multiplex PCR. A total of 18 metabolites of OCPs were identified in the workers' blood, most of which are either prohibited (DDT and its metabolites p, p'DDD and p, p'DDE, dieldrin, endrin, aldrin) and/or restricted (δ hexachlorocyclohexane, cis chlordane, methoxychlor, and endosulfan). The results obtained indicate lower levels of GST activity at higher OCPs concentrations detected in blood from exposed workers, together with an increase in OCP levels in individuals who presented the GSTT1*0 and GSTM1*0 genotypes. These conditions place the detoxification process in agricultural workers with null polymorphisms in the GST genes and high concentrations of OCPs in the blood (especially DDT and its metabolites, DDD and DDE) at risk, and increase their susceptibility to develop serious diseases. [ABSTRACT FROM AUTHOR]

Chlordane, a previously extensively utilized insecticidal pesticide, has since been prohibited, however, owing to its limited degradability, it continues to persist significantly in soil and water reservoirs, subsequently accumulating within plant and animal organisms, representing a substantial threat to human health. Despite extensive research conducted over the past few decades to investigate the toxic effects of chlordane, there remains a notable dearth of studies focusing on its impact on sleep activity. Therefore, in this study, the effects of short-term and long-term exposure to chlordane on the activity and sleep of Drosophila were investigated. When exposed to chlordane at a concentration of 1 μM, Drosophila lost body weight, decreased body size and resulted in lipid metabolism disorders. In addition, chlordane exposure altered the arousal and sleep behaviors of Drosophila. Short-term exposure to chlordane resulted in an increase in night-time sleep duration, while long-term exposure to chlordane resulted in an increase in activity and a decrease in sleep, as evidenced by a decrease in the duration of each sleep session and the appearance of sleep fragmentation. Under conditions of long-term chlordane exposure, reactive oxygen species levels were significantly up-regulated in Drosophila. Our results suggest that long-term chlordane exposure triggers oxidative stress damage in Drosophila , leading to sleep disruption. This study offers novel insights into the harmful impacts of environmental pollutants on human sleep patterns and proposes that mitigating the presence of chlordane in the environment could potentially contribute to the reduction of global sleep disorder prevalence. • Long-term chlordane exposure induces growth inhibition in Drosophila. • Chlordane exposure disrupts lipid metabolism in Drosophila. • Short-term chlordane exposure increases nighttime sleep duration. • Long-term chlordane exposure induces fragmented sleep patterns and mild hyperactivity in Drosophila. • Chronic chlordane exposure upregulates 4-HNE and increases oxidative stress levels [ABSTRACT FROM AUTHOR]

The present study examined how climate changes may impact the concentrations of lipophilic organochlorines (OCs) in the blood of fasting High Arctic common eiders (Somateria mollissima) during incubation. Polychlorinated biphenyls (PCBs), 1-dichloro-2,2-bis (p-chlorophenyl) ethylene (p,p'-DDE), hexachlorobenzene (HCB) and four chlordane compounds (oxychlordane, trans-chlordane and trans- and cis-nonachlor) were measured in females at chick hatching (n = 223) over 11 years (2007-2017). Firstly, median HCB and p,p'-DDE concentrations increased ~75 % over the study period, whereas median chlordane concentrations doubled (except for oxychlordane). PCB concentrations, in contrast, remained stable over the study period. Secondly, both body mass and clutch size were negatively associated with OC levels, suggesting that females with high lipid metabolism redistributed more OCs from adipose tissue, and that egg production is an important elimination route for OCs. Thirdly, the direct climate effects were assessed using the mean effective temperature (ET: air temperature and wind speed) during incubation, and we hypothesized that a low ET would increase redistribution of OCs. Contrary to expectation, the ET was positively correlated to most OCs, suggesting that a warmer climate may lead to higher OCs levels, and that the impact of ET may not be direct. Finally, potential indirect impacts were examined using the Arctic Oscillation (AO) in the three preceding winters (AO winter 1 - 3 ) as a proxy for potential long-range transport of OCs, and for local spring climate conditions. In addition, we used chlorophyll a (Chla) as a measure of spring primary production. There were negative associations between AO winter 1 and HCB, trans-chlordane and trans-nonachlor, whereas oxychlordane and cis-chlordane were negatively associated with Chla. This suggests that potential indirect climate effects on eiders were manifested through the food chain and not through increased long-range transport, although these relationships were relatively weak., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

The purpose of this study was to investigate the status of organochlorine pesticide residues in 186 ginseng samples collected in Jilin, People’s Republic of China. Based on the Chinese Pharmacopoeia 2015 method for detection of organochlorine pesticide residues in ginseng, 22 organochlorine pesticide residues were identified. Chlordane, aldrin, epichlorohydrin, and dieldrin and their isomers were not detected in ginseng from this region. Heptachlor was detected in only one ginseng sample, and the concentration did not exceed the maximum residual limit (MRL) prescribed in the Pharmacopoeia (0.05 mg/kg). Benzene hexachloride was detected in two samples, one of which was above the MRL. Hexachlorobenzene and pentachloronitrobenzene (quintozene) were found in 11.8 and 52.1% of the samples, respectively, and the residues in these samples exceeded the MRL by 4.3 and 8.6%, respectively. [ABSTRACT FROM AUTHOR]

Biomonitoring Equivalents (BEs) were developed for chlordane and toxaphene using one-compartment pharmacokinetic models and compared with biomonitoring data from the Canadian Health Measures Survey, Cycle 1 (2007–2009). A secondary objective was to examine the toxicities of the components of technical chlordane in a HEPG2 cell culture experiment. Oral reference doses were identified from national and international regulatory agencies and sources. Pharmacokinetic parameters were obtained from experimental data in rodent models. A set of BEs have been derived for the main chlordane isomers, cis-chlordane, trans-chlordane, cis-nonachlor, and trans-nonachlor, and the chlordane metabolite, oxychlordane. BEs were also derived for the main toxaphene isomers found in biota, Parlar No. 26, 50 and 62. Among the general Canadian population, no exceedances of chlordane or toxaphene BEs were observed. Based on the LC50 from the in vitro study, trans-nonachlor was the most toxic, and the trans-isomers were more toxic than the cis-isomers. The derived BE values can be used as screening guidelines to assess the risk of biomonitoring data in human populations. The results of an in vitro experiment suggest that trans-nonachlor is more toxic than technical chlordane and, therefore, the BE for this compound may need to be further lowered. • Biomonitoring equivalents (BEs) were developed for chlordane and toxaphene. • Biomonitoring data from the Canadian Health Measures Survey were analyzed. • Hazard quotients, based on the 99th percentile concentrations were less than zero. • No exceedances of the BEs were observed. • The derived BE values can be used as screening guidelines for biomonitoring data. [ABSTRACT FROM AUTHOR]

Abstract Background Epidemiologic studies suggest an increased risk of leukemia among individuals occupationally exposed to some organochlorine (OC) compounds. Associations between serum OC pesticide and polychlorinated biphenyl (PCB) levels and risk of acute myeloid leukemia (AML), the most common subtype of acute leukemia in adult populations, have not been evaluated prospectively in the general population. Objective We evaluated the risk of AML in relation to pre-diagnostic serum levels of OC pesticides and PCBs in a case-control study nested within the Janus Serum Bank Cohort. Methods Janus is a large population-based cohort containing biologic samples collected beginning in the early 1970s from ~318,000 individuals in Norway. Serum levels of 11 OC pesticides or their metabolites and 34 PCB congeners were measured in 56 AML cases and 288 controls. Conditional logistic regression was conducted to evaluate associations between lipid-adjusted serum OC levels and risk of AML. Results Higher serum levels of total chlordane/heptachlor metabolites were associated with AML risk (3rd vs. 1st tertile odds ratio (OR) = 2.26, 95% confidence interval (CI) = 0.91–5.63; p trend = 0.11). Significant exposure-response associations were observed for levels of heptachlor epoxide (3rd vs. 1st tertile OR = 2.85, 95% CI = 1.05–7.73; p trend = 0.02) and dieldrin (3rd vs. 1st tertile OR = 2.71, 95% CI = 1.07–6.83; p trend = 0.03). No significant exposure-response associations with AML risk were observed for total DDT or individual isomers and derivatives. Higher serum levels of p,p′-DDT showed a non-significant increase in risk, but the exposure-response became attenuated when co-adjusting for heptachlor epoxide or dieldrin levels. Serum PCB levels were not significantly associated with AML risk. Conclusions Our data suggest that higher serum levels of dieldrin and metabolites derived from chlordane/heptachlor are associated with risk of AML in the general Norwegian population, based on samples collected on average ~17 years before diagnosis. Further research in populations with historically high or recent exposure to DDT is warranted to assess the association with AML risk with body burden of specific DDT isomers and derivatives. Highlights • Organochlorines are a diverse group of environmentally persistent chemicals with varying degrees of carcinogenicity. • First population-based study of pre-diagnostic serum organochlorine levels and acute myeloid leukemia (AML) risk. • Higher serum levels of heptachlor epoxide, oxychlordane, and dieldrin were associated with increased AML risk. • Higher serum levels of total DDT and p,p′-DDE were not significantly associated with AML risk. [ABSTRACT FROM AUTHOR]

Highlights • POPs were detected in waste timber and recycled products in Japan in 2016–2017. • POPs concentrations were under the LPC limits of the Basel Convention. • Chlordane concentrations were higher in timber bearer than in timber column. • Timber column had little POPs contamination and is suitable for recycling. • Separation of timber will reduce POPs levels in recycled products. Abstract One of the major proportions of recycled persistent organic pollutants (POPs)-containing waste is timber originating from old buildings, utility poles, and cross-arms because POPs-based treatments were once a common means of preserving wood. In 2016 and 2017, we conducted the first survey in Japan on the residue concentrations of chlordanes (CHLs), pentachlorophenol (PCP), pentachloroanisole (PCA), and polychloronaphthalenes (PCNs) in waste timber (n = 55) and its recycled products (woodchip, n = 42; particle board, n = 3). In the recycled products, the highest concentrations detected were 0.86 mg kg−1 CHLs, 3.0 mg kg−1 PCP, 1.1 mg kg−1 PCA, and 2.6 mg kg−1 PCNs, which were one to two orders lower than the low POP content (LPC) limits for the environmentally sound management of wastes defined under the Basel Convention (50, 100, and 10 mg kg−1, respectively). In the waste timber, which included bearers and columns from demolished buildings, the highest concentrations were 15 mg kg−1 CHLs, 0.20 mg kg−1 PCP, and 0.036 mg kg−1 PCNs, no higher than about 30% of the LPC limit. The concentration of CHLs in timber bearer was significantly higher than those in timber column (p < 0.05). Although none of the waste timber or recycled products had concentrations exceeding the LPC limits, one means of ensuring low POP concentrations in recycled products is separating timber bearer from timber column when demolishing wooden buildings, according to the results in Japan. The timber column can be used to produce recycled products and the remaining timber can be used for heat utilization and power generation. [ABSTRACT FROM AUTHOR]

Chlordane is an organochlorine pesticide (OCP) that is environmentally persistent. Although exposures to OCPs including chlordane have been associated with elevated liver enzymes, current knowledge on OCPs' contribution to toxicant-associated steatotic liver disease (TASLD) and underlying sex-specific metabolic/endocrine disruption are still widely limited. Therefore, the objective of this study was to investigate the sex-dependent effects of chlordane in the context of TASLD. Age-matched male and female C57BL/6 mice were exposed to chlordane (20 mg/kg, one-time oral gavage) for two weeks. Female mice generally exhibited lower bodyfat content but more steatosis and hepatic lipid levels, consistent with increased hepatic mRNA levels of genes involved in lipid synthesis and uptake. Surprisingly, chlordane-exposed females demonstrated lower hepatic cholesterol levels. With regards to metabolic disruption, chlordane exposure decreased expression of genes involved in glycogen and glucose metabolism (Pklr , Gck), while chlordane-exposed females also exhibited decreased gene expression of HNF4A, an important regulator of liver identity and function. In terms of endocrine endpoints, chlordane augmented plasma testosterone levels in males. Furthermore, chlordane activated hepatic xenobiotic receptors, including the constitutive androstane receptor, in a sex-dependent manner. Overall, chlordane exposure led to altered hepatic energy metabolism, and potential chlordane-sex interactions regulated metabolic/endocrine disruption and receptor activation outcomes. [Display omitted] • Male and female mice were exposed to chlordane, an organochlorine pesticide mixture, for 2 weeks • Chlordane exposure resulted in decreased lipid levels and altered anti-oxidant capacity in males • Chlordane exposure increased circulating testosterone levels, indicative of a pro-androgenic effect • Exposed females demonstrated increased CAR activation and reduced Hnf4a mRNA levels [ABSTRACT FROM AUTHOR]

Soil contamination caused by pesticides poses a significant environmental challenge, and addressing it requires effective solutions. Bioremediation, combining the utilization of slurry-bioreactors and microbial consortia, emerges as an appropiated strategy to tackle this issue. Therefore, this research evaluated the chlordane (CLD) removal efficiency by a Streptomyces consortium through bioaugmentation of polluted soils, and slurry-bioreactors. For that, a Streptomyces defined consortium with CLD removal abilities was inoculated in soil microcosms and soil-slurry bioreactors (SB), with (SB-TSB) and without stimulation (SB-water). In soil, CLD presence has no negative effect on consortium growth. This was supported by comparing its duplication time (7.48 ± 0.14 h) with the obtained in the biotic control (7.45 ± 0.04 h). Furthermore, 17% of pesticide removal by microbial action was detected in the treated microcosms. In SB, the microbial development was not affected by the pesticide presence. In SB-TSB, the microbial growth was higher than in SB-water. This was supported by its lesser duplication time (7.27 ± 0.17 h) with respect to the non-stimulated systems (10.88 ± 0.29 h). However, SB-water showed the highest CLD removal ability (34.8%), with a concomitant increase in the chloride ion release. In the phytotoxicity test, the vigor index showed that the bioremediation in SB-water did not exert adverse effects greater than those generated by the CLD. Indeed, the root length increased after the treatment. These findings demonstrate the versatility of the Streptomyces consortium to remediate solid and semi-solid matrices impacted with pesticides, and the advantage of using bioaugmented SB to enhance the pollutants removal and accelerating the clean-up time required., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Tilapia nilotica (Oreochomis niloticus) is the major fish species consumed in Egypt, particularly due to its high nutritive value, palatability and relatively low price compared with other kinds of fishes or red meat. In Egypt, tilapia fish is caught directly from river Nile or cultured in a specified aquaculture. Organochlorine pesticides (OCPs) have been extensively used in Egypt and many African countries in the past century for the control of the agricultural pests. A major character of OCPs is their persistent bioaccumulation in the environment, especially in the food chain, where they can get reach to humans. There is few reports had investigated the current scenario of OCPs contamination in fish in Egypt, particularly in Upper Egypt cities such as Sohag. Additionally, fish is consumed cooked in Egypt not raw like many Asian countries. Therefore, this study aimed at monitoring the residue levels of different OCPs in tilapia fish caught from Upper Egypt (Sohag) and compared with either that from northern part of Egypt (Damietta) or with fish cultured in a control location (Abbasa). Additionally, the effect of different cooking methods (boiling, grilling and pan-frying) on the residue levels of OCPs was investigated. The tested OCPs included pp-DDT and its metabolites pp- DDD and pp-DDE; hexachlorohexanes (HCHs) including á HCH and ã HCH; heptachlor and heptachlor epoxide; aldrin and endrin; chlordane, methoxychlor and hexachloride benzene and were detected using electron capture gas chromatography equipped with Ni63 - electron capture detector. The recorded results revealed that tilapia collected from Damietta had the highest incidence of OCPs' contamination (75%), over than that collected from Sohag (60%) compared to control value (35%). All examined samples had OCPs residues within the maximum permissible limits (MPLs) set by world health organization. Pan-frying had the highest reduction effect on the OCPs' residues followed by grilling and boiling. The public health significance of the examined OCPs was also discussed. [ABSTRACT FROM AUTHOR]

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Organochlorine pesticides (OCPs) in South Africa have for the most part been banned, except dichlorodiphenyltrichloroethane (DDT) which is still used as malaria vector control. The aim of this study was to determine OCP residues in the aquatic fauna of one of South Africa's most populated areas, Soweto. Risk to human health through OCP exposure via fish consumption was investigated. Clarias gariepinus was chosen as bioindicator because it is an apex predator that is in abundance, but is also a valued food source. Dichlorodiphenyltrichloroethanes (DDTs), hexachlorocyclohexanes (HCHs), and chlordanes (CHLs) were detected in the fish tissue with the DDTs being the most prevalent at all sites. Of the three locations, Fleurhof, Orlando, and Lenasia, the latter location's fish had the highest ΣOCP load, ranging between 81 and 1190 ng/g wm. The DDTs were determined to be from historic use, whereas the CHL levels indicated more recent inputs. Although the possibility of illegal use cannot be excluded completely, the presence of OCPs outside of their allowed areas of use indicate that these compounds not only stay in the aquatic systems long term, but may be of concern in areas previously not considered high risk areas. The OCP residues in C . gariepinus from the study area pose an extremely high risk to human health when consumed, and has a cancer risk as high as 1 in 10. This potential problem should be kept in consideration when developing national health and conservation strategies. [ABSTRACT FROM AUTHOR]

Northern Cardinal eggs from six neighborhoods near Washington DC were analyzed for organochlorine pesticides and PCBs. All compounds were detected more frequently and at higher concentrations in more heavily urbanized neighborhoods. DDT (mostly as p,pʹ-DDE) was detected in all neighborhoods. p,pʹ-DDT was typically 0.5‒16 ng/g (ww) in most suburban neighborhoods but was not detected (< 0.1 ng/g) in more rural areas; however, p,pʹ-DDT was 127‒1130 ng/g in eggs from two suburban Maryland nests and comprised 65.7% of total p,pʹ-DDT isomers in the most contaminated sample, indicating recent exposure to un-weathered DDT. Total chlordane (sum of 5 compounds) was 2‒70 ng/g; concentrations were greatest in older suburban neighborhoods. Total PCB (sum of detected congeners) was < 5‒21 ng/g. Congener patterns were similar in all neighborhoods and resembled those typical of weathered mixtures. Results indicate that wildlife remains exposed to low concentrations of legacy contaminants in suburban neighborhoods and that cardinal eggs can be used to monitor localized contamination. [ABSTRACT FROM AUTHOR]

The study reports fortnightly atmospheric concentrations of organochlorine pesticides concomitantly measured at an urban, “industrial” and a remote location over a twelve month period in Kuwait to examine seasonal variability and urban-rural concentration gradients. The average ± SD (and range) of the ΣOC concentrations measured throughout the study period in decreasing order were urban, 505 ± 305 (range, 33–1352) pg m − 3 , remote, 204 ± 124 (4.5–556) pg m − 3 , and “industrial” 155 ± 103 (8.8–533) pg m − 3 . The concentrations of most OCs measured in this study, except for DDT and its metabolites, were higher at urban locations relative to their concentrations at remote location, in line with the literature on POPs regarding urban conurbations being sources of industrial chemicals. The most abundant pesticides measured throughout this study were dieldrin, pentachlorobenzene, hexachlorobenzene, ΣDDTs, ΣHCHs, and oxychlordane. Hexachlorobenzene concentrations were generally higher than those of pentachlorobenzene and are both strongly negatively correlated with temperature ( p < 0.05) at all sampling locations. Mean summertime concentrations were higher for hexachlorocyclohexanes, chlordanes, dieldrin, and DDT isomers, except for pp-DDT. This may suggest that concentrations of these compounds may be driven by temperature. [ABSTRACT FROM AUTHOR]

The sources and depositional history of OCPs (organochlorine pesticides), PCBs (polychlorinated biphenyls) and PAHs (polycyclic aromatic hydrocarbons) over the last 100 years were determined in two sediment cores collected in the Amazon region. It was possible to distinguish two depositional periods along the cores. The first period occurred before extensive anthropogenic effects were registered in the sediments. During this time interval, the concentrations of all OCPs and PCBs were below the detection limits (DL), and the PAH concentrations were low and essentially constant (58.19–124.28 ng g − 1 ). The second period starts in the mid-1960s and reflects the increased human influence in the area. The concentrations of OCPs, PCBs, and PAHs increased towards the top of the cores, varying between < DL to 72.67 ng g − 1 , < DL to 0.87 ng g − 1 and 331 to 2341 ng g − 1 , respectively. In general, OCP results showed trends corresponding to the production, usage and prohibition periods of POPs in Brazil. Compounds related to wood treatment, such HCHs and chlordanes, were predominant among the OCPs, which may be associated with many sawmills located in this region. The increase in PAH concentration after the 1960s is mainly due to forest fires, caused by the implementation of large-scale cattle ranches, which burned forests to create pastures. The background PAH concentrations before the 1960s are probably related to natural diagenetic processes. [ABSTRACT FROM AUTHOR]

The red-crowned crane ( Grus japonensis ) from eastern Hokkaido is classified as a Special Natural Monument in Japan. In this study, we determined the concentrations of persistent organic pollutants (POPs) in red-crowned crane muscle tissues (n = 47). Polychlorinated biphenyls (PCBs) had the highest median concentration (240 ng/g lipid weight), followed by dichlorodiphenyltrichloroethane and its metabolites (DDTs) (150 ng/g lipid weight), chlordane-related compounds (CHLs) (36 ng/g lipid weight), hexachlorobenzene (HCB) (16 ng/g lipid weight), hexachlorocyclohexanes (HCHs) (4.4 ng/g lipid weight), polybrominated diphenyl ethers (PBDEs) (1.8 ng/g lipid weight), and finally, Mirex (1.5 ng/g lipid weight). Additionally, a positive correlation was found among POP concentrations. No sex differences beyond body parameters were observed. Additionally, red-crowned cranes exhibited a high enantiomeric excess of (+)- alpha -HCH, with enantiomer fractions varying from 0.51 to 0.87 (average: 0.69). [ABSTRACT FROM AUTHOR]

Urban watersheds are significantly anthropogenically-altered landscapes. Most previous studies cover relatively short periods, without addressing concentrations, loads, and yields in relation to annual climate fluctuations, and datasets on Ag, Se, PBDEs, and PCDD/Fs are rare. Intensive storm-focused sampling and continuous turbidity monitoring were employed to quantify pollution at two locations in the Guadalupe River (California, USA). At a downstream location, we determined loads of suspended sediment (SS) for 14 yrs., mercury (HgT), PCBs, and total organic carbon (TOC) (8 yrs), total methylmercury (MeHgT) (6 yrs), nutrients, and trace elements including Ag and Se (3 yrs), DDTs, chlordanes, dieldrin, and PBDEs (2 yrs), and PCDD/Fs (1 yr). At an upstream location, we determined loads of SS for 4 yrs. and HgT, MeHgT, PCBs and PCDD/Fs for 1 yr. These data were compared to previous studies, climatically adjusted, and used to critically assess the use of small datasets for estimating annual average conditions. Concentrations and yields in the Guadalupe River appear to be atypical for total phosphorus, DDTs, dieldrin, HgT, MeHgT, Cr, Ni, and possibly Se due to local conditions. Other pollutants appear to be similar to other urban systems. On average, wet season flow varied by 6.5-fold and flow-weighted mean (FWM) concentrations varied 4.4-fold, with an average 7.1-fold difference between minimum and maximum annual loads. Loads for an average runoff year for each pollutant were usually less than the best estimate of long-term average. The arithmetic average of multiple years of load data or a FWM concentration combined with mean annual flow was also usually below the best estimate of long-term average load. Mean annual loads using sampled years were also less than the best estimate of long-term average by a mean of 2.2-fold. Climatic adjustment techniques are needed for computing estimates of long-term average annual loads. [ABSTRACT FROM AUTHOR]

Digital databases on 444 stations were used to carry out statistical analysis of regularities in the spatial distribution of Barents Sea water pollution. The analysis was focused on the concentrations in water of heavy metals (Cd, Cr, Cu, Hg, Ni, Pb, and Zn) and toxic organic compounds: hexachlorocyclohexanes, hexachlorobenzene, chlordans, DDT, polychlorbiphenyls, polycyclic aromatic hydrocarbons, and normal paraffins. The statistical analysis of data on pollutants was carried out along two major directions in their distribution: the vertical-in the surface and bottom water layers; and the horizontal-over water masses. Reliable differences were identified in the pollution level of different water masses of the Barents Sea. The frontal zone was found to concentrate pollution. [ABSTRACT FROM AUTHOR]

The present study was conducted to highlight the existing level of organochlorine-pesticides (OCPs) from human milk ( n = 45) and blood serum ( n = 40) of female workers who pick cotton in Khanewal District, southern Punjab, Pakistan. Source apportionment, congener-specific analysis, and risk surveillance of OCPs are reported from human milk and blood samples. Levels of OCPs in milk and blood serum samples ranged from 15.7 ppb to 538.3 ppb and from 16.4 ppb to 747.1 ppb, respectively, and were lower than previously published reports from other regions of the globe. Congener-specific analysis revealed that DDTs were predominant, followed by hexachlorocyclohexane, chlordane, and hexachlorobenzene. Calculated results for source apportionment analysis suggested that contamination load was a new input of DDTs as well as the historic use of lindane in the study area. Levels of OCPs in milk and blood serum were significantly ( p < 0.05) correlated with age, time period of picking cotton, and number of children. Health risk revealed that female workers had risk of cancer among 1 per million; however, noncarcinogenic risks were not considerable. Environ Toxicol Chem 2017;36:1193-1201. © 2016 SETAC [ABSTRACT FROM AUTHOR]

An improved analytical method was developed for the simultaneous quantification of numerous androgen disruptors—vinclozolin, dichlorodiphenyltrichloroethanes (DDTs), hexachlorocyclohexanes, chlordane, heptachlor, dieldrin, endrin, and aldrin—in fish, followed by GC with tandem MS (MS/MS). Extraction, cleanup, and MS/MS parameters of analytes were optimized. The LOQs of the analytes ranged from 0.3 to 3.7 μg/kg. Reasonable recoveries (73.7-119.2%) were demonstrated at different spike levels with RSDs lower than 12.2%. This method was applied for the analysis of the target analytes in fish samples sold in Hangzhou, China, and DDTs were found to be the predominant contaminants in fish samples. [ABSTRACT FROM AUTHOR]

Epidemiological studies indicate that exposure to persistent organic pollutants is positively associated with the prevalence of obesity. To delineate the potential role of technical-grade chlordane in obesity development, chlordane metabolism and chlordane-induced metabolic changes were investigated in mice fed high-fat diet (HFD) over a 6-week period. Gas chromatography–electron capture detector analysis showed that HFD induced more accumulation of technical chlordane in the liver, muscle and adipose tissue. The enantioselectivities of oxychlordane in selected tissues were also influenced by HFD. 1 H NMR-based liver metabolome indicated that technical chlordane can enhance the metabolic alterations induced by HFD. Compared with the low-fat diet (LFD) group, no differences were observed in the LFD + chlordane group. However, as many as 16 metabolites were significantly different between the HFD group and HFD + chlordane group. Moreover, compared to the LFD + chlordane group, the abundances of 24 metabolites significantly increased or decreased in the HFD + chlordane group. Twenty metabolites were altered in the HFD group compared to the LFD group. Tryptophan profiling suggested that both chlordane and HFD can disturb tryptophan catabolism. These interactions between technical chlordane and HFD suggest that technical chlordane is a candidate obesogen. [ABSTRACT FROM AUTHOR]

This study evaluates the bioaccumulation of unweathered (U) and weathered (W) CuO in NP, bulk and ionic form (0–400 mg/kg) by lettuce exposed for 70 d in soil co-contaminated with field incurred chlordane. To evaluate CuO trophic transfer, leaves were fed to crickets (Acheta domestica) for 15 d, followed by insect feeding to lizards (Anolis carolinensis). Upon weathering, the root Cu content of the NP treatment increased 214% (327 ± 59.1 mg/kg) over unaged treatment. Cu root content decreased in bulk and ionic treatments from 70–130 mg/kg to 13–26 mg/kg upon aging in soil. Micro X-ray fluorescence (μ-XRF) analysis of W-NP-exposed roots showed a homogenous distribution of Cu (and Ca) in the tissues. Additionally, micro X-ray absorption near-edge (μ-XANES) analysis of W-NP-exposed roots showed near complete transformation of CuO to Cu (I)-sulfur and oxide complexes in the tissues, whereas in unweathered treatment, most root Cu remained as CuO. The expression level of nine genes involved in Cu transport shows that the mechanisms of CuO NPs (and bulk) response/accumulation are different than ionic Cu. The chlordane accumulation by lettuce upon co-exposure to CuO NPs significantly increased upon weathering. Conversely, bulk and ionic exposures decreased pesticide accumulation by plant upon weathering. The Cu cricket fecal content from U-NP-exposed insects was significantly greater than the bulk or ion treatments, suggesting a higher initial NP accumulation followed by significantly greater elimination during depuration. In the lizard, Cu content in the intestine, body and head did not differ as a function of weathering. This study demonstrates that CuO NPs may undergo transformation processes in soil upon weathering that subsequently impact NPs availability in terrestrial food chains. [ABSTRACT FROM AUTHOR]

Because of mountain cold-trapping, the soil in the Tibetan Plateau may be an important global sink of organochlorine pesticides (OCPs). However, there are limited data on OCPs in the soils of the Tibetan Plateau. In addition, the atmospheric transport and deposition mechanisms of OCPs also need to be further studied. In this study, the sampling area covered most regions of the Tibetan Plateau. The detection frequencies of ΣChlordane (sum of trans -chlordane, cis -chlordane and oxychlordane), HCB, ΣNonachlor (sum of trans - and cis -nonachlor), DDTs, ΣEndo (sum of endosulfan-I, endosulfan-II and endosulfate), aldrin, HCHs, ΣHeptachlor (sum of heptachlor and heptachlor epoxide), mirex and dieldrin were 100%, 98.3%, 96.6%, 94.8%, 89.7%, 87.9%, 62.1%, 55.2%, 32.8% and 6.9%, respectively. DDTs (with arithmetic mean values of 1050 ng kg − 1 dw) and HCHs (393 ng kg − 1 ) were the principal OCPs in cultivated soils, whereas ΣEndo (192 ng kg − 1 ) and ΣChlordane (152 ng kg − 1 ) were the principal OCPs in non-cultivated soils. Local use of DDTs, dicofol and HCHs may be an important source of OCP accumulation in the soil of the Tibetan Plateau. Aldrin and endosulfan are considered to be good indicators for studying atmospheric transport and deposition of OCPs from South Asia and Southeast Asia. Two zones with high OCP levels were found in the southeast and northwest of the Tibetan Plateau. The zones have dissimilar pollution sources of OCPs and are influenced by different factors that affect their precipitation scavenging efficiency. The amount of precipitation was the dominant factor in the southeast, whereas large differences in temperature and wind speed were the dominant factors in the northwest. [ABSTRACT FROM AUTHOR]

The aim of the study was to investigate the effect of chlordane, heptachlor and mirex, on hormonal regulation of the force of myometrial contractions. Myometrial, endometrial, granulosa and luteal cells as well as strips of myometrium from non-pregnant cows were incubated with three insecticides at environmentally relevant doses (0.1, 1 or 10 ng/ml). None of the insecticides affected the viability of studied cells. Chlordane stimulated, while heptachlor and mirex inhibited, secretion of testosterone and estradiol from granulosa cells as well as secretion of progesterone from luteal cells, respectively. Secretion of oxytocin (OT) from granulosa cells was increased after incubation with all studied insecticides. Only mirex stimulated OT secretion from luteal cells, while heptachlor inhibited this effect. None of them affected synthesis of OT in luteal cells and prostaglandins (PGF2 and PGE2) secretion from uterine cells, except PGE2 secretion from endometrial cells was decreased when the cells were incubated with 0.1 ng/ml of chlordane. Basal and OT-stimulated myometrial contractions were increased by mirex and decreased by heptachlor. The data show that the insecticides altered secretory function of ovarian cells. Heptachlor and mirex affected also myometrial contractions in vitro , but uterine secretion of prostaglandins were not involved in the mechanism of that adverse effect of insecticides. The data indicate on potential of these insecticides to disturb fertilisation, blastocyst implantation or even the length of gestation. [ABSTRACT FROM AUTHOR]

Populations are exposed to pesticides through diet on a daily basis. However, there is no research guiding how to evaluate dietary pesticide exposure, and researchers used 1-day, 3-days, 7-days or even longer dietary survey to evaluate without any consensus. It is important for dietary pesticide evaluation to identify the minimum survey days. To increase knowledge of this, a data combination was applied between a two-wave consecutive repeated-measures study in Baoding City and the Fifth China Total Diet Study. Further policy consistency on pesticides were evaluated to explain its credibility. We computed the sensitivity and specificity to evaluate how well different days of dietary survey classify participants with high exposure, and calculated the minimum days required to estimate the participant-specific mean at different acceptable error range. With 1 day of dietary survey, the classification sensitivity was low (<0.6) for total HCH, endosulfan, chlordane, cyhalothrin, allethrin, and prallethrin; that for the other pesticides was high sensitivity (≥0.6). Sensitivity increased as the number of days increased, and the maximum marginal sensitivity increase (≥0.039) occurred from 1 to 2 days for all pesticides except phenothrin, whose maximum marginal sensitivity increase (0.042) occurred from 2 to 3 days. The specificity increased gradually from 0.8 to 0.9 from 1 to 7 days. Under the acceptable error range of 0.5%, 3-28 days were required for participant-specific mean estimation and 1-7 days were required when acceptable error range was shrunk in 1%. Only 1 day was enough if 5% error range was acceptable. In conclusion, 3 days in the study period was cost-effective to distinguish high exposure group, and it rose to 7 when estimating participant-specific mean from a conservative perspective. This study can serve as a reference to determine the minimum survey days for epidemiological studies employing dietary surveys., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Chlordane is an organochlorine pesticide that contains a mixture of components, some of which are chiral. Analysis of enantiomers can provide insights into the mechanisms of their sources, pathway, and fate. The objectives of this work were: (i) to review the published literature that reported chlordane enantiomer concentrations in various environmental compartments; (ii) to evaluate the applicability of a model developed by Hegeman and Laane (2002) for predicting the relative distribution of various chiral pesticides in the environment. This model predicts that enantiomer deviation increases in the following order: air, water, soil, molluscs, fish/birds, marine mammals, specific tissues, and enzymes; (iii) to determine the relative ranking of plants within the model. All data were converted into an enantiomer fraction and aggregated by environmental compartment using bootstrap averaging to compare to model predictions. Enantiomer distributions of cis-chlordane, trans-chlordane, oxychlordane, and heptachlor exo-epoxide were reported in soil, air, water/sediments, plants, and animals. Based on aggregated average estimates for enantiomer fraction, the deviation from racemic increased in the following order for cis-chlordane: water/sediments = lower trophic aquatic organisms < air < fish < soil < plants (all combined) < seal < polar bear < bird < whale; for trans-chlordane: fish < water/sediments < lower trophic aquatic organisms < air < soil < plants (all combined) < seal < whales < bird < polar bear; and for heptachlor exo-epoxide: plants (all combined) < fish < soil = whale < water/sediments < bird < air < seal < polar bear. Depending on the species used to represent marine mammals, the Spearman's rank-order correlation coefficients of observed data against model predictions were + 0.75 or + 0.84 for cis-chlordane, + 0.41 or + 0.49 for trans-chlordane, and -0.59 or + 0.12 for heptachlor exo-epoxide. This suggests that the model is applicable for cis- and trans-chlordane, but not for heptachlor exo-epoxide. The fundamental mechanisms behind the observed enantiomeric enrichment are of eminent importance in understanding the enantioselective deviations. [ABSTRACT FROM AUTHOR]

In support of the United Nations Environment Programme (UNEP) global monitoring plan under the Stockholm Convention concentrations of persistent organic pollutants (POPs) were determined during two years in air from 42 countries in Asia, Africa, Latin America, and the Pacific by using polyurethane foams installed in passive samplers. The compounds included were polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), polybrominated diphenylethers (PBDEs), one polybrominated biphenyl and hexabromocyclododecane (HBCD) diastereomers. Total-DDT and PCBs were the highest in concentrations in about 50% of the samples, which shows their high persistency. Total DDT in air from the Solomon Islands ranged from 200 to 600 ng/polyurethane foam disk (PUF). However, at most locations, a decreasing trend is observed for PCBs, DDT and most other OCPs. Patterns varied per country with e.g. elevated dieldrin in air from Barbados and chlordane in air from the Philippines. A number of OCPs, such as heptachlor and its epoxides, some other chlordanes, mirex and toxaphene have decreased down to almost undetectable levels. PBB153 was hardly found and penta and octa--mix related PBDEs were also relatively low at most locations. HBCD and the decabromodiphenylether were more prominent at many locations and may even still increase. To draw more holistic conclusions more colder climate countries should be included in this program., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Vrije Universiteit Amsterdam. Published by Elsevier Ltd.. All rights reserved.)