Distribution, source, and risk of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in urban and rural soils around the Yellow and Bohai Seas, China

Occurrence, spatial distribution, and ecological risk of benzotriazole UV stabilizers (BUVs) in sediments from Bohai sea of China

Benzotriazoles are a class of ultraviolet absorbents which absorb UV ranging from 280 to 400 nm and are widely used in personal care products and industrial production. Their residues in environmental matrices have received great concern in recent years, but most studies have focused on pollution in water and few have examined BUVs in marine sediments. In this study, we investigated the occurrence, potential sources, and ecological risk of 15 types of BUVs in the sediments of Bohai Sea in China for the first time. The total concentrations of the 15 BUVs ranged from 0.139 to 4.125 ng/g dw with a median concentration of 0.340 ng/g. UV-327 and UV-360 were predominant among the BUV congeners, accounting for 22.6% and 17.7% of the total concentration of Σ15BUVs, respectively. The detection frequencies of the BUV congeners generally exceeded 95%, reflecting the wide use and persistence of these chemicals. The concentrations of the BUV congeners in this study were one order of magnitude lower than those in other areas. Moreover, the distributions of BUVs presented a decreasing gradient from nearshore to offshore, indicating that coastal input was the main influencing factor. Two potential primary sources, plastic manufacturing and domestic wastewater, were identified via principle component analysis. The ecological risks of BUVs to aquatic organisms in the sediments were evaluated using the risk quotient (RQ) method. Generally, the risk to aquatic organisms from exposure to BUVs in Bohai Sea could be considered low at the measured concentrations. While our study provides important new insight into the ecological risks of BUVs in the estuary, further research on the pollution levels and toxicity risks of BUVs in Bohai Sea should be conducted to better understand the ecological effect of these pollutants.

Accumulation of typical persistent organic pollutants and heavy metals in bioretention facilities: Distribution, risk assessment, and microbial community impact

Bioretention facilities have proven highly effective in removing pollutants from runoff. However, there is a concerning paucity of research on the contamination characteristics and associated risks posed by refractory pollutants in these facilities following long-term operation. This research focuses on the distribution, sources, microbial community impact, and human health risks of pollutants in eight bioretention facilities that have been operational for 5-11 years. The results showed that the distribution of Cu, Zn, and Cd was closely related to anti-seepage measures. PAHs, PCBs, and OCPs primarily accumulated in the surface, with concentrations ranging from 7.42 to 20.34 mg/kg, 31.8-77.3 μg/kg, and 60.5-163.6 μg/kg, respectively. Their concentrations inversely correlate with the depth of the media. Although the majority of contaminants remained below their respective risk thresholds, their concentrations typically exceeded those of background soil values, indicating an enrichment phenomenon. Source analysis revealed that PAHs primarily originate from oil combustion, PCBs were linked to their related industrial products, DDTs had their main sources in technical DDx and residues from the use of dicofol, while HCHs were traced back to historical residues from agricultural activities. Microbial α-diversity (Chao 1 and Shannon) decreased by 8.3-23.4% and 0.8-4.4%, respectively, in different facilities after long-term operation. The most dominant microbial phylum in the facilities was Proteobacteria (all relative abundances >48%). The total relative abundance of dominant genera was 6.7-34.3% higher than the control site, and Pseudomonas, a typical POPs-heavy metal degrading bacterium, had the highest relative abundance (>1.2%). Cu, Zn, and Cd present no non-carcinogenic risks and have low potential ecological risks. However, the lifetime cancer risk for PAHs is 10-6 ∼10-4 in most facilities and is of concern. The cancer risk for PCBs is acceptable, while OCPs pose a low cancer risk only for children.

Under explored roles of microbial ligninolytic enzymes in aerobic polychlorinated biphenyl transformation

Polychlorinated biphenyls (PCBs) are persistent organic pollutants in the environment that are responsible for many adverse health effects. Bioremediation appears to be a healthy and cost-effective alternative for remediating PCB-contaminated environments. While some microbial species have been observed to be capable of transforming PCBs, only two different microbial pathways (rdh and bph pathways) have been described to be involved in PCB transformations. Ligninolytic enzymes have been observed or are under suspicion in some microbial PCB transformations. However, the role of these promising PCB-transforming enzymes, which are produced by fungi and some aerobic bacteria, is still unclear. The present review describes their role by identifying microbial PCB-transforming species and their reported ligninolytic enzymes whether proven or suspected to be involved in PCB transformations. There are several lines of evidence that ligninolytic enzymes are responsible for PCB transformations such as (1) the ability of purified laccases from Myceliophthora thermophila, Pycnoporus cinnabarinus, Trametes versicolor, Cladosporium sp, and Coprinus cumatus to transform hydroxy-PCBs; (2) the increased production of laccases and peroxidases by many fungi in the presence of PCBs; and (3) the enhanced PCB transformation by Pseudomonas stutzeri and Sinorhizobium meliloti NM after the addition of ligninolytic enzyme enhancers. However, if the involvement of ligninolytic enzymes in PCB transformation is clearly demonstrated in some fungal species, it does not seem to be implicated in all microbial species suggesting other still unknown metabolic pathways involved in PCB transformation and different from the bph and rdh pathways. Therefore, PCB transformation may involve several metabolic pathways, some involving ligninolytic enzymes, bph or rdh genes, and some still unknown, depending on the microbial species. In addition, current knowledge does not fully clarify the role of ligninolytic enzymes in PCB oxidation and dechlorination. Therefore, further studies focusing on purified ligninolytic enzymes are needed to clearly elucidate their role in PCB transformation.

Concentration and non-dietary human health risk assessment of pesticide residues in soil of farms in Golestan province, Iran

Detection of pesticide residues in soil samples was conducted using UHPLC-MS/MS. Non-dietary health risk assessment was conducted using calculate chronic daily intake (CDI) from ingestion, inhalation and dermal contact pathways and following non-carcinogenic and carcinogenic risks in the adults and adolescent. The rank order of pesticide in soil based on their concentration was malathion (0.082 mg kg-1)> cyproconazole (0.019 mg kg-1)> propargite (0.018 mg kg-1)> butachlor (0.016 mg kg-1) > chlorpyrifos (0.0067 mg kg-1)> diazinon (0.0014 mg kg-1)> imidacloprid (0.0007 mg kg-1). Hazard index (HI) values obtained of exposure to pesticides in soil in adults and adolescent were 0.0012 and 0.0035, respectively. Hence, exposed population are at the acceptable range of non-carcinogenic risk (HI < 1). Cancer risk (CR) values due to propargite in soil via ingestion pathway in adults and adolescent were 2.03E-09 and 2.08E-09, respectively; therefore, carcinogenic risk due to the exposure to pesticide contaminated soil was safe range (CR < 1E-06).

Associations of polychlorinated biphenyl and organochlorine pesticide exposure with hyperuricemia: modification by lifestyle factors

Recent research has reported positive associations of exposure to polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) with hyperuricemia. However, most of these studies have primarily focused on the individual effects of PCB/OCP exposure. We aimed to explore the associations of both individual and combined PCB/OCP exposure with hyperuricemia and examine whether such associations could be modified by lifestyle factors. The cross-sectional study recruited 2032 adults between March and May 2019 in Wuhan, China. Logistic regression and weighted quantile sum (WQS) regression were applied to explore the relationship of individual and combined PCB/OCP exposure with hyperuricemia, while considering the modified effects of lifestyle factors. Of the 2032 participants, 522 (25.7%) had hyperuricemia. Compared with the non-detected group, the detected groups of PCB153 and PCB180 exhibited a positive association with hyperuricemia, with OR (95% CIs) of 1.52 (1.22, 1.91) and 1.51 (1.20, 1.90), respectively. WQS regression showed that PCB/OCP mixture was positively associated with hyperuricemia (OR: 1.31, 95% CI: 1.08, 1.58). PCB153/PCB180 exposure, combined with an unhealthy lifestyle, has a significant additive effect on hyperuricemia. Overall, PCB/OCP mixture and individual PCB153/PCB180 exposure were positively associated with hyperuricemia. Adherence to a healthy lifestyle may modify the potential negative impact of PCBs/OCPs on hyperuricemia.

Pollution characteristics, distribution, and source analysis of carbazole and polyhalogenated carbazoles in coastal areas of Bohai Bay, China

Polyhalogenated carbazoles (PHCZs) are a class of emerging environmental contaminants formed by the substitution of hydrogen on carbazole (CZ) benzene rings with halogens (Cl, Br, I) with potential dioxin-like toxicity, and they have been frequently detected in various environmental media and organisms recently. Nevertheless, co-research of CZ/PHCZs with PAHs is very limited. In addition, I-PHCZs, which are believed to be much more toxic than CZ, Cl-PHCZs and Br-PHCZs, have a few data in sediments previously. The concentration and distribution of CZ/PHCZs and PAHs were analyzed in 18 surface sediments of Bohai Bay, China. There is a significant correlation (R = 0.64, P＜0.05) between PHCZs and PAHs, and principal component analysis (PCA) also indicating that they may have a certain similarity in origin. Additionally, total CZ and PHCZs was up to 230.57 ng/g dw in the studied samples, which was approximately 1-2 orders of magnitude lower than PAHs and other common persistent organic pollutants (POPs). The compositions of the CZ/PHCZs in our study were dominated by CZ (2.74-18.28, median 2.92 ng/g dw), 3,6-dichlorocarbazole (n.d-6.78, median 0.97 ng/g dw) and 3,6-iodocarbazole (n.d-12.68, median 1.65 ng/g dw). Results of this study discovered the varying origins of CZ and PHCZs and/or a complexity of anthropogenic influences and natural sources processes, and revealed a wide distribution of CZ/PHCZs across the studied. Moreover, more attention should be paid by comparing CZ/PHCZs with other widely distributed POPs.

Distribution, sources, and ecological risk assessment of polychlorinated biphenyls (PCBs) in the estuary of Dagu River, China

Four different types of 0-30 cm soil/sediment samples were collected from aquaculture land, farmland, industrial land and river bottom sediment in the estuary area of Dagu River, and the pollution status and sources of 7 PCB congeners were analyzed. The results showed that the mean values of Σ7PCBs in soil/sediments of different land use types were 5.01 ng g-1 dw for industrial land, 3.6 ng g-1 dw for estuarine sediments, 2.09 ng g-1 dw for farmland soil and 1.78 ng g-1 dw for farming land. All samples were at low pollution levels and pose little ecological risks. PCBs in the samples are mainly comprised of highly chlorinated biphenyls, and their content decreases gradually with increasing sampling depth. Based on the principal component analysis, it is concluded that the main source of PCBs in the study area is shipping activities, in addition to atmospheric transport and sedimentation sources.

Urbanization-driven soil degradation; ecological risks and human health implications

Urban soils contaminated with heavy metals and pesticide residues are of great concern because of their adverse impact on human health. A total of 66 agricultural topsoil samples (15 cm) were collected to represent the study area and determine how anthropogenic activities adversely affect soil quality and human health. Sampling was conducted in the summer, when it was dry and hot, and in the winter, after atmospheric deposition. Seventeen potentially hazardous metals/metalloids (Ag, As, Al, B, Ba, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Mo, Pb, Se, Zn, and V) were measured in the soils. The mean concentrations of metals ranged between 0.05 and 8080 mg/kg, and their distribution was site-specific, with high pollution at the sampling sites owing to proximity to human activities. In agricultural areas, the greatest arsenic concentration was recorded at 48 mg/kg. The potential ecological risk index (PERI) and health hazard index (HI) were calculated, as well as metal contamination indices including contamination factor (Cf), geo-accumulation index (Igeo), and pollution load index (PLI). The mean PLI was calculated to be 4.89, indicating that the area is highly polluted. The potential ecological risk index showed remarkably high risks for As, Cd, and Hg, and moderate risks for Ni and Pb. The arsenic hazard index (HI) was greater than one (2.41) in children, indicating a risk of exposure through ingestion. Pesticide residue analyses were performed in areas where the metal intensity was high. Banned or restricted organochlorine pesticide (OCPs) residues, including, dieldrin, endrin ketone, endosulfan I, II, heptachlor, heptachlor epoxide, lindane (γ-HCH), PP-DDD, and methoxychlor, were detected between 0.002 and 1.45 mg/kg in the soil samples.

Chlorinated pesticides and PCB residues in the Egyptian Western Desert oases sediments

This preliminary investigation aimed to detect concentrations of chlorinated pesticides and PCBs in 40 sediment samples from three desert oases located in Kharga, Dakhla and Farafra in western Egypt. The residues of 18 PCBs and 16 chlorinated pesticides were measured by GC-MS/MS (SRM) method. The results showed that PCBs and pesticides were present in all studied samples. The concentrations of individual PCBs ranged from undetected to 3.99 ng/g dw in all these sediment samples. The total residue of pesticides (ng/g, dry weight) in sediment samples also varied from 5.18 to 25.92, 5.41 to 29.49, and 5.93 to 24.19 ng/g dw for the Kharga, Dakhla and Farafra Oases, respectively. The concentrations of PCBs and chlorinated pesticides detected in these oasis sediments were lower than that reported for other worldwide locations. According to the recorded concentrations in this baseline study of PCBs and total DDTs, the results revealed the minimal risks to organisms and people in the studied area according to the Effects Range-Low (ERL) and Effects Range-Median (ERM) guideline values.

Combination of slurry-bioreactors and actinobacteria consortia as strategy to bioremediate chlordane-contaminated soils

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.

Spatio-temporal distribution of organochlorine pesticides in agricultural soils of southeast China during 2014-2019

Organochlorine pesticides (OCPs) are organic pollutants that are persistent and undegradable in the environment. To investigate their residual concentrations, spatial and temporal distributions, and the relationship with the crops planted, 12 individual OCPs in 687 soil samples from Jiangsu, Zhejiang and Jiangxi provinces of southeast China were examined. The detection frequencies of OCPs in the studied areas were 1.89%-64.9%. The concentrations of dichloro-diphenyl-trichloroethanes (DDTs), hexachlorocyclohexanes (HCHs), and endosulfans ranged from 0.01 to 5659 μg/kg, 0.03-3.58 μg/kg, and 0.05-3235 μg/kg, respectively. Jiangsu was mainly contaminated by p,p'-DDT, p,p'-DDD and endosulfan sulfate, Zhejiang was more polluted by OCPs except δ-HCH, and Jiangxi was more vulnerable to the contamination of OCPs except o,p'-DDE. The partial least-squares discrimination analysis (PLS-DA) model with RX2 36.3-36.8% revealed that compounds with similar chemical properties tended to appear in the same year and month. All crop lands were polluted by DDTs and Endosulfans. The highest concentrations of DDTs and Endosulfans were found in citrus and vegetable fields, respectively. This study offers new insight into the layout and partitioning of OCPs in agricultural land and into insecticide management on public health and ecological safety.

Status of different anthropogenic organic pollutants accumulated in sediments from Olt River Basin, Romania: From distribution and sources to risk assessment

Some organic pollutants including organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) have been banned from production worldwide, but due to their toxicity and persistence are still of concern. Also, unintentional by-products of combustion and industrial processes such as polycyclic aromatic hydrocarbons (PAHs), represent a permanent threat to the safety of the environment and the population. In this study, surface sediment samples from the middle and lower Olt River Basin (ORB), Romania, including dams, the main tributaries and the confluence with Danube River were collected during seasonal sampling campaigns in 2019 and analyzed for 13 OCPs, 12 PCBs and 15 PAHs in order to evaluate the impact of the main anthropogenic activities in the area (industrial activities and agriculture) and the ecological status of the ORB. The registered levels of OCPs, PCBs and PAHs in surface sediments varied from low to significantly polluted environments, indicating a clear spatial distribution between sites based on concentrations and congener profiles correlated with the influence of anthropogenic activities in the surrounding area. Based on some molecular diagnostic ratio and multivariate statistical analysis, both non-point sources and point sources deposition by surface runoff or atmospheric deposition were identified. Overall, the contamination profile of the study area reveals significant amounts of organochlorine compounds, resulting from the industrial production of chlorinated products, including lindane, but also from the long-term agricultural use of both HCHs and DDTs, more than half of the sites having levels that pose a potential risk for benthic organisms. Therefore, levels of POPs in the hot-spots sampling locations raise numerous concerns about the safety of the environment and the population in the region, requiring immediate actions.

The derivation of soil generic assessment criteria for polychlorinated biphenyls under the agricultural land scenario in Pearl and Yangtze River Delta regions, China

The agricultural soils in China are suffered from serious polychlorinated biphenyls (PCBs) contamination, however, the valid management standards for farmland are absent to efficiently control the health risks of PCBs exposure. This study analyzed the contamination characteristics and main composition of PCBs in agricultural soils of the southeastern China from the published literature over the past 20 years, and derived the regional generic assessment criteria (GAC) using an exposure modelling approach for individual and total PCBs (∑PCBs) via multiple exposure pathways such as ingestion of soil and dust, consumption of vegetables, dermal contact with soil and dust, ingestion of soil attached to vegetables, and inhalation of soil vapour and soil-derived dust outdoors under the agricultural land scenario. It is identified that the averaged ∑PCBs concentration of 80.03 ng g^-1 under the 95 % lower confidence limit with an unacceptable health risk of 4.8 × 10^-6 has significantly exceeded the integrated generic assessment criteria (expressed as GAC_int) of 16.5 ng g^-1. Accordingly, the exposure pathways from the consumption of agricultural produces and indirect ingestion of soil attached to vegetables contributed up to 62 %-88 % of the total exposure, followed by 11 %-33 % of the soil ingestion and 2 %-6 % of dermal contact. The derived GAC_int for ∑PCBs is extremely valuable to effectively assess and manage the PCBs contamination in agricultural soils of China.

Comparison of pollution status and source apportionment for PCBs and OCPs of indoor dust from an industrial city

In this study, the pollution status of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) was investigated in indoor and outdoor dust from three different functional areas of Hefei, China. The relationship between the concentrations of PCBs and OCPs and different influencing factors in dwellings was studied. The results showed that the concentrations of PCBs and OCPs were higher in samples from dwellings with higher smoking frequency, lower cleaning frequency, higher floors and smaller household size. The results of Spearman's correlation coefficient analysis indicated that PCBs and OCPs were not consistently associated with each other, while sources of low-chlorinated PCBs and high-chlorinated PCBs were different. Scanning electron microscopy (SEM) shows the shape of indoor dust was a mixture of blocky, flocculated, spherical structures, and irregular shapes. The results of principal component analysis (PCA) and positive matrix factorization model (PMF) showed that the PCBs and OCPs of indoor dust came from both indoor and outdoor sources between local and regional transport. Carbon (δ¹³C) and Nitrogen (δ¹⁵N) stable isotope results indicate or show that the indoor dust (δ¹³C: - 24.37‰, δ¹⁵N: 6.88‰) and outdoor dust (δ¹³C: - 12.65‰, δ¹⁵N: 2.558‰) is derived from fossil fuel, coal combustion, road dust, fly ash, C4 biomass and soil. Potential source contribution factor (PSCF) and concentration weighted-trajectory analysis suggest that sources of pollutants were local and regional transport from surrounding provinces and marine emissions. The average daily dose (adult: 8.20E-04, children: 2.37E-03) of pollutants and the carcinogenic risks (adult: 1.23E-02, children: 2.65E-02) were relatively greater for children than adults. This study demonstrates the utility of SEM to characterize indoor dust morphology while combining PMF, PSCF, and stable isotope methods in identifying indoor PCBs and OCPs sources and regions.

Target and non-target analysis of organochlorine pesticides and their transformation products in an agrochemical-contaminated area

Organochlorine pesticides show biological toxicity and their degradation typically takes many years. Previous studies of agrochemical-contaminated areas have mainly focused on limited target compounds, and emerging pollutants in soil have been overlooked. In this study, we collected soil samples from an abandoned agrochemical-contaminated area. Target analysis and non-target suspect screening by gas chromatography coupled with time-of-flight mass spectrometry were combined for qualitative and quantitative analysis of organochlorine pollutants. Target analysis showed that dichlorodiphenyltrichloroethane (DDT), dichlorodiphenyldichloroethylene (DDE), and dichlorodiphenyldichloroethane (DDD) were the main pollutants. With concentrations between 3.96 × 10⁶ and 1.38 × 10⁷ ng/g, these compounds posed significant health risks at the contaminated site. Non-target suspect screening identified 126 organochlorine compounds, most of which were chlorinated hydrocarbons and 90% of the compounds contained a benzene ring structure. The possible transformation pathways of DDT were inferred from proven pathways and the compounds identified by non-target suspect screening that had similar structures to DDT. This study will be useful for studies of the degradation mechanism of DDT. Semi-quantitative and hierarchical cluster analysis of compounds in soil showed that the distribution of contaminants in soil was influenced by the types of pollution sources and distance to them. Twenty-two contaminants were found in the soil at relatively high concentrations. The toxicities of 17 of these compounds are currently not known. These results improve our understanding of the environmental behavior of organochlorine contaminants in soil and are useful for further risk assessments of agrochemical-contaminated areas.

Spatial characteristics, sources and exposure risk of polychlorinated biphenyls in dusts and soils from an urban environment in the Niger Delta of Nigeria

Chlorinated organic compounds, such as polychlorinated biphenyls (PCBs), are a threat to both humans and the environment because of their toxicity, persistence, and capacity for long-range atmospheric transport. The concentrations of 28 PCB congeners, including 12 dioxin-like and seven indicator PCBs, were investigated in soils, and indoor and outdoor dusts from Port Harcourt city, Nigeria, in order to evaluate the characteristic distribution patterns in these media, their sources, and possible risk. The PCB concentrations varied from 4.59 to 116 ng g^-1 for soils, and from 1.80 to 23.0 ng g^-1 and 2.73 to 57.4 ng g^-1 for indoor and outdoor dusts respectively. The sequence of PCB concentrations in these matrices was soil > outdoor dust > indoor dust. The composition of PCBs in these matrices indicated the prevalence of lower chlorinated PCBs in indoor and outdoor dusts, while the higher chlorinated congeners were dominant in soils. Di-PCBs were the predominant homologues in indoor dusts, while deca-PCBs were the most prevalent homologues in outdoor dusts and soils. The TEQ values of dioxin-like PCBs in 60 % of the soils, 100 % of the indoor dust, and 30 % of the outdoor dust were above the indicative value of 4 pg TEQ g^-1 established by the Canadian authority. The hazard index (HI) values for exposure of adults and children to PCBs in these media were mostly greater than one, while the total cancer risk (TCR) values exceeded the acceptable risk value of 10^-6, which indicate probable non-carcinogenic and carcinogenic risks resulting from exposure to PCBs in these media. Source analysis for PCBs in these matrices shows that they originated from diverse sources.

Organochlorine pesticides and polycyclic aromatic hydrocarbons in serum of Beijing population: Exposure and health risk assessment

Organochlorine pesticides (OCPs) and polycyclic aromatic hydrocarbons (PAHs) are widespread environmental contaminants, but large-scale human biomonitoring and health risk assessment data on these contaminants remain limited. In this study, concentrations of 6 OCPs and 5 PAHs were determined by GC-MS/MS in 1268 human serum samples which were collected from the participants in 2017 Beijing Chronic Disease and Risk Factor Surveillance. The detection frequencies of OCPs and PAHs ranged from 64.7 % to 96.5 % and 89.4 % to 99.6 %, respectively. The most abundant contaminants in OCPs and PAHs were pentachlorophenol (PCP) and pyrene (Pyr) with median concentrations reaching up to 3.13 and 8.48 μg/L, respectively. Nonparametric tests were employed to assess the correlations among contaminants levels, demographic characteristics (age, gender, body mass index, residence) and serum biochemical indexes. Significantly higher serum levels of all PAHs were observed in suburb residents than that in urban residents (P < 0.001). Binary logistic regression analysis demonstrated that exposure to benzo(a)pyrene (OR 2.17 [1.29, 3.63]), phenanthrene (OR 1.06 [1.02, 1.11]), fluoranthene (OR 1.04 [1.02, 1.07]) and Pyr (OR 1.02 [1.01, 1.03]) might increase the occurrence of hyperglycemia, and exposure to hexachlorobenzene (HCB) (OR 1.53 [1.05, 2.22]) and pentachlorobenzene (OR 1.14 [1.02, 1.27]) were positively associated with hyperlipidemia. Furthermore, the hazard quotients (HQs) for serum HCB, PCP and p,p'-dichlorodiphenyldichloroethylene were calculated based on health-based guidance values to predict health risks. 0.2 % and 4.3 % of serum samples showed HQ values exceeding 1 for HCB and PCP, respectively, in case of the non-carcinogenic risk, while 23.1 % of HQs for HCB were above 1 in case of the carcinogenic risk for a risk level 10^-5. Our study reveals that the body burden of the Beijing general population relative to OCPs and PAHs was nonnegligible. The past exposure of HCB and PCP might adversely affect the health status of the Beijing population.

National-scale monitoring of historic used organochlorine pesticides (OCPs) and current used pesticides (CUPs) in Chinese surface soil: Old topic and new story

Along with the restriction and prohibition of historic used organochlorine pesticides (OCPs), current used pesticides (CUPs) were widely used as alternatives. In order to investigate the pollution characteristics of pesticides, the levels and spatial distributions of OCPs and CUPs in 154 surface soil across China were comprehensively compared. Totally, 107 target pesticides were screened, and 20 OCPs and 34 CUPs were detected. The numbers of co-occurred pesticides in single soil sample were from 17 to 36 indicating the diversity and complexity of pesticides pollution. The concentrations of OCPs in urban soils were higher than rural soils, while rural > urban for CUPs. Furthermore, obviously different spatial distribution patterns were found for OCPs and CUPs. For OCPs, the secondary distribution pattern was dominant. For CUPs, the primary distribution pattern was obviously observed due to their current extensive usage. In addition, higher concentrations of both CUPs and OCPs were accumulated in the Northeast China Plain due to long-range atmospheric transport and deposition. Along with the old topic of OCPs, the study pointed out the preliminary understanding of CUPs pollution characteristic in surface soil of China, which provided a new story with the deep understanding of their environmental fate in both China and the world.

Development of structural equation models to unveil source-sink switches of mid-latitude soils for semi-volatile banned pesticides

A variety of semi-volatile banned pesticides (SVBPs) are ubiquitous in soils of mid-latitude regions. SVBPs undertake complicated soil-gas exchange processes in mid-latitude regions, challenging the understanding of source or sink roles of soils for the semi-volatile contaminants. Herein, we develop structural equation models (SEMs) to unveil source or sink roles of mid-latitude soils (Liaoning, China) in winter and summer for 12 SVBPs (7 organochlorine and 5 organophosphorus pesticides). The 12 SVBPs exhibit different distribution patterns in soils, dependent of sampling seasons, soil characteristics, topographic/climate conditions of soil sites and chemical properties of compounds. SEM Model I (winter) and Model II (summer) reveal the distribution patterns of SVBPs in soils over season changes, indicating sink-source switches of soils for SVBPS from winter to summer. In winter, soil is a sink of 12 SVBPs in the study area, associated with the inputs of SVBPs in soils by air-particulate partition and dry depositions. However, in summer, soil is mainly a source of the same contaminants, mainly through the volatilization and leaching of SVBPs in soils. The sink-source switches of soils for SVBPs are usually dependent of chemical properties of compounds to higher extents than soil characteristics and topographic/climate conditions of soil sites, though these parameters pose different influences in winter and summer. It has been revealed that soil acts as a sink of SVBPs in winter, associated with the inputs of SVBPs in soils by air-particulate partition and dry depositions, whereas soil acts as a source of SVBPs in summer, mainly through the volatilization and leaching of SVBPs in soils. This finding may provide new insights into the unique distribution patterns of SVBPs in soils in mid-latitude regions.

Organochlorine pesticides in the urban, suburban, agricultural, and industrial soil in South Korea after three decades of ban: Spatial distribution, sources, time trend, and implicated risks

Organochlorine pesticides in soil samples across urban, suburban, agricultural, and industrial sites were analyzed every year between 2013 and 2016 in South Korea. The study aims to understand the residual status, diminution of occurrence from the South Korean environment, and its risk to humans after three decades of the ban. A general decreasing trend of OCPs has been observed over the years. The OCP concentrations were below the guideline values prescribed for soil pollution. Metabolites like p,p'-DDD and endosulfan sulfate contributed a major portion to the total OCP concentration over the years. The agricultural sites showed higher OCP levels than other site types. Compositional profile and diagnostic ratios suggested that the occurrence of DDT and endosulfan residues were due to historical inputs, but those of HCH and chlordane reflect recent usage in some pockets. The calculated incremental lifetime cancer risk was within the safety limit for all age groups across the genders in the majority of the sites. It is evident that the OCP load on soil is decreasing since the ban on usage. However, regular monitoring with a special focus on metabolites can be an effective control measure to regulate and eliminate the contamination of OCPs.

Residue level, occurrence characteristics and ecological risk of pesticides in typical farmland-river interlaced area of Baiyang Lake upstream, China

Baiyang Lake is the largest freshwater lake in North China, playing an important role in aquatic products production and eco-environment improvement. Traditional organochlorine pesticides were not enough to reflect ecological risk. We performed the high-throughput and non-targeted screening to identify the high-residue and wide-distribution pesticides at farmland-river interlaced area. We firstly reported the residue level and spatio-temporal distribution of typical pesticides in soils and waters (SP1–SP13) near Fuhe river in 2020–2021. The mean recoveries of eight pesticides ranged from 79.4 to 129%. The residues were 0.250–3530 ng/L (water) and 2.79 × 10⁻³–647 μg/kg dw (soil), respectively. Thiamethoxam was dominant with the high-residue proportion (HRP) of 53–95% (water, HRP > 50%) and 63–97% (soil, HRP > 60%), respectively. Most of pesticides almost have no significant season-change. The risk quotient (RQ) model results showed that although most pesticides have no aquatic risk (RQ < 0.01), carbendazim and propionazole deserved attention. The individual thiamethoxam at nearly half of the sites exhibited high terrestrial risk (RQ, 1.070–1.682), while propiconazole was at medium risk (SP1, SP2, SP8, and SP9) and high risk (SP12). The RQ_all were in the range of 0.4541–3.327 (earthworm), 0.0239–0.4552 (algae), 0.1094–1.103 (aquatic invertabrates), and 0.1657–1.923 (fish), respectively, so co-residue caused joint toxic effect to aquatic invertebrates.

Quantitative Retention (Structure)–Activity Relationships in Predicting the Pharmaceutical and Toxic Properties of Potential Pesticides

The micellar liquid chromatography technique and quantitative retention (structure)–activity relationships method were used to predict properties of carbamic and phenoxyacetic acids derivatives, newly synthesized in our laboratory and considered as potential pesticides. Important properties of the test substances characterizing their potential significance as pesticides as well as threats to humans were considered: the volume of distribution, the unbonded fractions, the blood–brain distribution, the rate of skin and cell permeation, the dermal absorption, the binding to human serum albumin, partitioning between water and plants’ cuticles, and the lethal dose. Pharmacokinetic and toxicity parameters were predicted as functions of the solutes’ lipophilicities and the number of hydrogen bond donors, the number of hydrogen bond acceptors, and the number of rotatable bonds. The equations that were derived were evaluated statistically and cross-validated. Important features of the molecular structure influencing the properties of the tested substances were indicated. The QSAR models that were developed had high predictive ability and high reliability in modeling the properties of the molecules that were tested. The investigations highlighted the applicability of combined chromatographic technique and QS(R)ARs in modeling the important properties of potential pesticides and reducing unethical animal testing.

Legacy organochlorines in estuarine sediment in relation to socioeconomic pattern in multi-coastal watersheds

Estuarine sediment quality is highly associated with anthropogenic activities in watersheds. This study attempts to couple socioeconomic patterns with estuarine sediment quality via legacy organochlorines in 14 Chinese coastal watersheds. Sedimentary concentrations of HCHs, DDTs, and PCBs showed a significant spatiality in estuary, up to 48.7 ± 15.1, 89.0 ± 46.4, and 54.5 ± 17.2 ng g-1, which were predominated by β-HCH, p,p'-DTs, and tri- to penta-PCBs, respectively. Ecological risk of organochlorines was negligible except few moderate risks for DDTs and PCBs against the first class quality of the marine sediment quality guidelines of China. Sedimentary DDT and PCB concentrations were significantly delineated by an environmental Kuznets curve model as a function of non-agricultural GDP per capita in watersheds, while HCHs by an increasing linear model. Findings of this study provide a tool to quantify the contribution of anthropogenic development in watershed to environmental change in estuary across the world.

Status of Dieldrin in vegetable growing soils across a peri-urban agricultural area according to an adapted sampling strategy

Since the fifties, organochlorine pesticides (OCPs) had been used in agriculture to protect vegetables. Two decades after their ban by the Stockholm convention in 2001, OCPs are still present in agricultural soils inducing vegetable contamination with concentrations above Maximum Residue Level (MRL). This is a major concern for a 5 km² peri-urban vegetable growing valley located in the south west of France. In the present work, the sampling method was developed to clarify the spatial distribution of one OCP, Dieldrin, and its relationship with soil properties at the scale of study area. A total of 99 soil samples was collected for physicochemical analyses and Dieldrin concentrations. Results show Dieldrin concentrations in soils up to 204 μg kg^-1. The horizontal distribution of this pesticide is heterogeneous at the study area scale but homogeneous in each reference plot studied. About 85% of the contamination was located in the top soil layers (0-40 cm depth), but Dieldrin may still be quantified at a depth of 80 cm. Among all soil physicochemical parameters analysed, SOM was the most significantly related (P < 10^-4) with Dieldrin concentrations, once different grain size fractions were considered. Moreover, results indicate a 33 times higher Dieldrin concentration and/or extractability for coarse sand than for other grain size fractions. These results show that the developed sampling method is adapted for the study area scale as it helps understanding the factors influencing the spatial distribution of Dieldrin. Historical amendments are the predominant factor for the horizontal contamination and deep ploughing for the vertical contamination. Also, the variations of coarse sand repartition in soils prevents identification of relationships between SOM and Dieldrin contamination in bulk soil. Further investigation is required to explain these relationships but these results highlight why no clear relationship between OCPs and SOM was previously identified.

Level, source, and distribution of organochlorine pesticides (OCPs) in agricultural soils of Tanzania

This study investigated the level, composition, and spatial and vertical distribution of the organochlorine pesticides (OCPs) at 0-2 cm and 2-20 cm in the agricultural surface soils from Southeastern to Central-western Tanzania. Although the most abundant OCPs were DDT with a mean concentration of 2.29 ng/g, dieldrin (1.57 ng/g), and methoxychlor (0.79 ng/g), HCH was the most dominant (with detection frequency of 88%). OCP dominance was in the Southern Highlands, which is the most productive agricultural zone. Though there were indicators of recent inputs for some sites, OCP contamination was mainly historical. DDT contamination was dominated by p,p'-DDE and resulted from both technical DDT and dicofol while HCH contamination was dominated by γ-HCH and resulted from both technical HCH and lindane. Based on depth, the OCPs dominated mainly the upper 2 cm, which was associated with soil and environmental factors rather than recent inputs since most of the detected compounds were historical. Nevertheless, some sites showed exceptional high abundance in the lower soil with more concentration of parent compounds. Therefore, this study recommends the need for further studies on the influence of soil properties on OCPs' transport in the soil, surface water, and air. Besides, detection of recent inputs at some sites calls for more mapping of the OCPs in the country to strengthen their control and prevention of future risks.

Ecological risk of chlorinated organic pollutants in a semi-enclosed bay impacted by aquaculture

Semi-enclosed bays are used for critical economic activities such as ports, aquaculture, and human settlement due to their topography and ocean connectivity. However, the role of these geomorphological characteristics on the accumulation of chlorinated organic pollutants in semi-enclosed bays is poorly understood. We investigated the spatiotemporal distribution and potential ecological risk of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in sediments from Shantou Bay, a semi-enclosed bay. The ∑PCB concentration was 258-1297 ng g^-1 and 59.6-651 ng g^-1 in the dry season and wet season, respectively. Sediments collected downstream and upstream the aquaculture farms had significantly lower DDT concentrations than those collected close to the aquaculture discharge points. The ratio of DDT and its metabolites indicated that there was possible fresh input of DDTs into Shantou Bay. However, no significant spatial trend was observed in the PCB profiles. The concentrations of PCBs and OCPs in Shantou Bay were above the China Marine Sediment Quality Class I suggesting remediation was essential to ensure the aquatic systems could be safely used for fisheries, swimming, or as marine protected areas. Furthermore, the potential ecological risk of DDTs was high as it exceeded the effects thresholds at all sites. Seasonal variations in human activities, resuspension of historical contaminants due to physical oceanographic, climatic and hydrological factors, and contaminant trapping probably contributed to the changes in organic pollutant distribution in the semi-enclosed bay.

Risk of dietary intake of organochlorine pesticides among the childbearing-age women: A multiple follow-up study in North China

Exposure to organochlorine pesticides (OCPs) can cause adverse health effects in the female population. We investigated the dietary OCP intake of childbearing-age women living in large agricultural areas of Northern China, as well as their associated health risks. Ten childbearing-age women were recruited during 2015-2016. Their weekly dietary intake diaries and food samples were collected over the course of five visits. The OCP residues of 322 food samples from seven categories (i.e., cereal, vegetable, fruit, fish, meat, egg, and milk) were analyzed by gas chromatography-mass spectrometry. The average concentrations of the total hexachlorocyclohexanes (ΣHCH), dichlorodiphenyltrichloroethanes and their metabolites (ΣDDX), endosulfans (ΣES), and dieldrin and endrin (ΣDrin) in all food categories were, overall, much lower than the maximum residue limits. Relative high mean residues of ΣDrin and ΣES were found in fruits (ΣDrin: 0.687 ng g-1 wet weight (w.w.), ΣES: 2.24 ng g-1 w.w.) and vegetables (ΣDrin: 0.690 ng g-1 w.w., ΣES: 2.11 ng g-1 w.w.). The estimated daily dietary intake (EDI) of these compounds was calculated, with mean levels of 10.6 (ΣES) > 4.37 (ΣDrin) > 1.51 (ΣHCH) > 0.850 (ΣDDX) ng kg-1 day-1. Women during the heating period (from January to March) tended to ingest more ΣHCH, ΣDDX, ΣDrin, and ΣES. Overall, women had no obvious non-carcinogenic and carcinogenic risks due to intake of OCPs, but 83.9% of them has potential carcinogenic risk, with estimated life carcinogenic risk (LCR) exceeding 10-6. Furthermore, women had a higher potential carcinogenic risk during the heating period (mean LCR: 1.33 × 10-5) than during the non-heating period (mean LCR: 8.50 × 10-6). ΣDrin was the dominant OCP responsible for health risks, followed by ΣHCH. We concluded that women in North China still have some dietary OCP intake, especially during the heating period.

Metagenomics reveals functional profiling of microbial communities in OCP contaminated sites with rapeseed oil and tartaric acid biostimulation

Organochlorine pesticides (OCPs) contaminated sites pose great threats to both human health and environmental safety. Targeted bioremediation in these regions largely depends on microbial diversity and activity. This study applied metagenomics to characterize the microbial communities and functional groups composition features during independent or simultaneous rapeseed oil and tartaric acid applications, as well as the degradation kinetics of OCPs. Results showed that: the degradation rates of α-chlordane, β-chlordane and mirex were better when (0.50% w/w) rapeseed oil and (0.05 mol L^-1) tartaric acid were applied simultaneously than singular use, yielding removal rates of 56.4%, 53.9%, and 49.4%, respectively. Meanwhile, bio-stimulation facilitated microbial enzyme (catalase/superoxide dismutase/peroxidase) activity in soils significantly, promoting the growth of dominant bacterial communities. Classification at phylum level showed that the relative abundance of Proteobacteria was significantly increased (p < 0.05). Network analysis showed that bio-stimulation substantially increased the dominant bacterial community's proportion, especially Proteobacteria. The functional gene results illustrated that bio-stimulation facilitated total relative abundance of degradation genes, phosphorus, carbon, nitrogen, sulfur metabolic genes, and iron transporting genes (p < 0.05). In metabolic pathways, functional genes related to methanogenesis and ammonia generation were markedly upregulated, indicating that bio-stimulation promoted the transformation of metabolic genes, such as carbon and nitrogen. This research is conducive to exploring the microbiological response mechanisms of bio-stimulation in indigenous flora, which may provide technical support for assessing the microbial ecological remediation outcomes of bio-stimulation in OCP contaminated sites.

Pesticides driven pollution in Kuwait: The first evidence of environmental exposure to pesticides in soils and human health risk assessment

Soil pollution from pesticide residues is a key concern due to the high soil accumulation of pesticides and their human toxicity. Pesticide concentration of surface soil samples from the Sulaibiya agricultural field located in Kuwait was assessed in the present study. The study also investigated health risk assessment for both children and adults based on the residual concentrations. The average concentration of ƩOCPs (sum of organochlorine pesticides) along the present study was 3062 pg/g. The residual concentration of ƩOCPs was comparatively lower as compared to other locations around the world. Out of the 11 observed locations, A, B, and D locations indicated higher concentrations of ƩOCPs. The results indicated that DDT showed higher concentrations 692.87 pg/g in soil samples as compared to the other pesticides. Cancer risks of OCP via ingestion, dermal contact and inhalation of soil particles suggested that all stations were in a safe zone. However, locations A, B and D were closer to the low-risk band. The distribution pattern for each form of organochlorine pesticides (OCP) was different in Sulaibiya, indicating the non-simultaneous use of different groups of OCPs in this region. Multivariate statistical analysis based on cluster analysis identified three classes, 1, 2 and 3 of pesticides, suggesting these are from the same sources. Principle component analysis (PCA) showed that soil physicochemical properties influence the pesticides in soil samples. The results provides the baseline data of pesticides in soils from Kuwait.

Enhanced plant-microbe remediation of PCBs in soil using enzyme modification technique combined with molecular docking and molecular dynamics

The study on the enhanced mechanisms of the enzymes involved in plant absorption, plant degradation, and microbial mineralization in the remediation of soils contaminated with polychlorinated biphenyls (PCBs) is of great significance for the application of plant-microbe combined remediation technique in PCB-contaminated soils. The present study first used a combination of molecular docking and molecular dynamics methods to calculate the effects of the plant absorption enzyme, plant degradation enzyme, and microbial mineralization enzyme on the PCBs in the soil environment. A multifunctional plant degradation enzyme was constructed with three functional roles of absorption, degradation, and mineralization using amino acid sequence recombination and site-directed mutagenesis to modify the template of plant degradation enzyme. Finally, using the Taguchi experimental design-assisted molecular dynamics simulation method, the suitable external environmental conditions of plant-microbe combined remediation of the PCB-contaminated soil were determined. In total, six multifunctional plant degradation enzymes were designed, which exhibited a significantly improved efficiency of PCB degradation. In comparison to the complex of plant absorption enzyme, plant degradation enzyme, and microorganism mineralization enzyme (6QIM-3GZX-1B85), the six multifunctional plant degradation enzymes exhibited significantly higher efficiency (2.10-2.38 times) in degrading the PCBs, with a maximum of 2.69 times under suitable external environmental conditions.

A highly sensitive photoelectrochemical aptasensor based on BiVO4 nanoparticles-TiO2 nanotubes for detection of PCB72

In this work, a simple and highly sensitive photoelectrochemical (PEC) aptasensor has been developed for detecting PCB72 based on TiO₂ nanotubes (NTs) decorated with BiVO₄ nanoparticles (NPs). The BiVO₄ NPs-TiO₂ NTs composites prepared through a simple hydrothermal method exhibit good visible-light adsorption ability, high PEC response and perfect photo-excited stability. The synthesized composites were explored as the photoactive sensing materials for development of a PEC sensing platform for the first time. Here, Au nanoparticles (NPs) were first deposited the composites, and the anti-PCB72 aptamer molecules were immobilized on the Au NPs-deposited BiVO₄ NPs-TiO₂ NTs. The developed PEC aptasensor exhibits high sensitivity and specificity for PCB72 with a wide linear range from 1 ng/L to 500 ng/L and a low detection limit of 0.23 ng/L. The application of the aptasensor was evaluated by determining PCB 72 in the environment water samples. Thus, a simple and efficient PEC sensing platform was established for detecting the content of PCBs in the environment.

Prenatal exposure to organochlorine pesticides is associated with increased risk for neural tube defects

Neural tube defects (NTDs) are among the most common and disabling fetal congenital defects. Organochlorine pesticides (OCPs) are ubiquitous in the environment. In this study, 119 women who had NTD-affected pregnancies (cases) and 119 women who delivered healthy neonates (controls) were recruited in a rural area of Northern China. We used concentrations of OCPs in umbilical cord tissue as markers of prenatal exposure to investigate the association between in utero exposure to OCPs and NTD risk. Concentrations of 20 OCPs were quantified by gas chromatography-mass spectrometry, and 16 of the 20 OCPs were included in the analyses. Odds ratios and 95% confidence intervals (95% CIs) for the associations between levels of individual OCPs and NTD risk were estimated separately with logistic regression adjusting for potential confounders. The combined effects of exposure to the 16 OCPs as a mixture were analyzed with Bayesian kernel machine regression (BKMR). Logistic regression showed that the risk for NTDs increased 5.44-fold (95% CI, 2.21-13.41) for β-hexachlorocyclohexane, 2.51-fold (95% CI, 1.07-5.86) for endosulfan I, 3.78-fold (95% CI, 1.60-8.89) for endosulfan II, 3.42-fold (95% CI, 1.44-8.12) for ο,ρ'-dichlorodiphenyldichloroethane, and 2.89-fold (95% CI, 1.22-6.86) for ρ,ρ'-dichlorodiphenyltrichloroethane when the concentration of each of these OCPs was above its median (exposed) compared to below its median (non-exposed). Other OCPs were not associated with NTD risk in multivariate models. In BKMR, NTD risk increased almost linearly with concentrations of the 16 OCPs as a mixture, which suggests joint effects on NTD risk. Exposure to α-hexachlorocyclohexane, β-hexachlorocyclohexane, endosulfan II, ο,ρ'-dichlorodiphenyldichloroethane, and ρ,ρ'-dichlorodiphenyldichloroethane was associated with an increased risk for NTDs when levels of the remaining 15 OCPs were taken into account. Taken together, these findings show that prenatal exposure to OCPs is associated with increased risk for NTDs.

Dynamic transcriptome response in Meretrix meretrix to Aroclor 1254 exposure

Polychlorinated biphenyls (PCBs) are well-known persistent organic pollutants; they have toxic effects on the immune system, reproductive system, and endocrine system by changing the metabolism of the body. To elucidate the underlying molecular mechanism, the clam Meretrix meretrix was exposed to 10 and 1000 ng/L Aroclor 1254 and natural seawater (control). Samples from clams exposed to natural seawater and those exposed to Aroclor 1254 for 1 and 3 days were individually collected for transcriptome analysis. After assembly, more than 535,157 transcripts with a mean length of 949 bp and an N50 length of 1279 bp were obtained; a final set of 177,142 unigenes was generated. In the present study, 5101 differentially expressed genes were identified. The differentially expressed genes were related to detoxification metabolism, oxidative stress, immune response, and endocrine system disruption. Of these genes, under the Aroclor 1254 exposure, cytochrome P450 20A1 (2.06-4.46 folds), glutathione S-transferase (2.25-3.80 folds), multidrug resistance-associated protein 1-like (1.49-2.92 folds), peroxidase-like protein (1.33-4.26 folds), lysozyme (1.61-2.05 folds), bcl-2 like 1 protein (1.14-2.29 folds) and vitellogenin (1.09-1.19 folds) showed been significantly induced expressed. At the same time, some genes were down regulated, including cytochrome P450 2J5 (-1.20 ~ -2.86 folds), cytochrome P450 3A24 (-1.40 ~ -4.08 folds), C1q (-1.27 ~ -1.66 folds), Sulfotransferase (-1.51 ~ -1.84 folds), monocarboxylate transporter 10 (-1.30 ~ -4.70 folds), 3-beta hydroxysteroid dehydrogenase (-1.43 ~ -2.81 folds) and beta-galactosidase (-1.23 ~ -2.23 folds). Furthermore, it showed that the expression levels of CYP2J5, glutathione S-transferase, 3-beta hydroxysteroid dehydrogenase and beta-galactosidase had time responses and dose responses. The present study provided insights into the toxic effects of Aroclor 1254 exposure in M. meretrix.

Distribution characteristics and environmental fate of PCBs in marine sediments at different latitudinal regions: Insights from congener profiles

Sediments were sampled from Hangzhou Bay (HB), the South China Sea (SCS), and Antarctica (AZ) to better understand the distribution characteristics and environmental fate of polychlorinated biphenyls (PCBs) at different latitudes. Numerous PCB congeners (68) were detected among the sampling sites, supporting the ubiquity of PCB congeners. High and low chlorinated congeners dominated the PCB profiles of AZ and SCS, respectively, whereas the PCB homologues were evenly distributed in the HB. As a fraction of low chlorinated PCBs originates from an exogenous input, the low mean ratios of ∑Tetra-CBs to ∑PCBs and ∑Tetra-CBs to the sum of ∑Tri- and ∑Di-CBs suggest that microbial transformation of PCBs is weak in marine surface sediments, if any occurs at all. Furthermore, PCB contamination levels in marine sediments may be primarily influenced by latitude rather than pollution sources. Thus, the findings of this study suggest that Antarctica is becoming a prospective hotspot for PCBs.

Comparative study on the pollution status of organochlorine pesticides (OCPs) and bacterial community diversity and structure between plastic shed and open-field soils from northern China

The pollution status of organochlorine pesticides (OCPs) and microbial community in plastic shed and open-field soils may be different due to the significant variations in environmental factors between the two cultivation modes. However, the differences remain unclear. We conducted a regional-scale survey to investigate the pollution level, distribution, and sources of 20 OCPs, and to evaluate the soil physicochemical properties and bacterial community in soils from plastic shed and open-field locating the north areas of China. We found that levels of total OCPs in the plastic shed soils were significantly higher than those in the nearby open-field soils. Most of these OCPs were attributed to historical application, except for dichlorodiphenyltrichloroethanes (DDTs) due to the fresh input along with dicofol application. Soil pH (for both cultivation modes) and total organic carbon (TOC) content (only for plastic sheds) were significantly correlated with the total OCP concentrations. Additionally, microbial diversity and richness were generally lower in plastic shed soils than in nearby open-field soils for each region. The bacterial community variation among different regions might be principally determined by the soil type. Soil pH had the greatest impact on the microbial community across all plastic shed and open-field samples. These results provide a better understanding of the environmental impact and ecological risk of OCPs in soils with different cultivation modes.

Stock status, urban public perception, and health risk assessment of obsolete pesticide in Northern Ethiopia

Pesticides are widely used chemicals in the agricultural sector to control pests, diseases, and other plant pathogens. This study aimed to assess the storage conditions of pesticides, the community perception, and health risk of pesticide exposure. The study was conducted in three different zonal cities in Ethiopia, East Africa, namely Mekelle, Aksum, and Alamata. Community perception was studied in a community living near a pesticide stockpile with a cross-sectional study of 384 randomly selected households. In addition, questionnaires were administered, a field investigation was conducted, and focused group discussions with responsible bodies were held to assess storage condition. Accidental ingestion and inhalation were considered to determine average daily exposure (ADE) and incremental lifetime cancer risk (ILCR). This study reveals that all obsolete and banned hazardous pesticides were stored in one area. The storage sites were only secured with simple locks and exposed to rain, sunlight, and temperature variation. The majority of the residents perceived that pesticides pose risk to human health (46.6%), to the environment (28.4%), and to animals (25%). The association between residence proximity of respondents to the store and side effect of obsolete pesticides is statistically significant (p = 0.008). Children aged 2 years and below have higher ADE when exposed to the same concentration of contaminant via inhalation. The probability of a person developing cancer was very low with a risk value of 2.54E-08 and 1.65E-07 as a result of exposure to air containing heptachlor and dichlorodiphenyltrichloroethane (DDT), respectively.

Pesticide residues in agricultural topsoil from the Hainan tropical riverside basin: Determination, distribution, and relationships with planting patterns and surface water

Pesticide residues were assessed in rice-vegetable rotation topsoil from tropical riverside basin. The 256 tropical topsoil samples from the Nandu River Basin (NRB) and Wanquan River Basin (WRB) in Hainan (China) were taken from 2018 to 2019. A total of 32 current-use pesticides (CUPs) and nine legacy pesticides (LPs) were detected using a method based on a QuEChERS technique. The highest residues were from the fungicide carbendazim (257.2 μg/kg) and the insecticide imidacloprid (139.4 μg/kg). The nine LPs (8 organochlorine pesticides and chlorpyrifos) were detected in 84.4% of the samples with mean concentrations ranging from 0.02 to 675.4 μg/kg. The two most commonly detected pesticides were imidacloprid and emamectin benzoate with detection rates of 96.8% and 91.8%, respectively. The highest total concentration of pesticides from the NRB and WRB was detected in July. The highest average number of multi-residues (16) was recorded in January, compared to 14 and 12 in July and November, respectively. There was a significant correlation between the multiple pesticide residues in soil and vegetable planting types (p < 0.01). There was a significant positive correlation between the pesticide number in topsoil and the pesticide number in water (p < 0.01). The multiple pesticide residues found in surface water were consistent with those in topsoil, suggesting a potential risk of water contamination in the rice-vegetable rotation.

Assessment of the spatial distribution of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in urban soil of China

Long-term (2004-2018) persistent organic pollutants (POPs) data were collected for urban soils of China. The dataset included concentrations of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in soils, comprising a range of different compounds. Understanding the source of OCP and PCB pollution is an important step in controlling and reducing pollution levels in the environment. This study aimed to analyze the spatio-temporal distribution, pollution sources, and potential health risks of OCPs and PCBs in urban soils in different regions of China. It was found that the total OCP concentrations ranged from 7.6 to 37331 μg/kg with a mean value of 2861 μg/kg, and PCBs concentrations ranged from 0.3 to 123467 μg/kg with a mean value of 4984 μg/kg. The highest OCP concentrations were observed in Beijing and Hebei, whereas the highest PCB concentrations were found in the Zhejiang province. The geographical distribution showed that the total mean concentration of POPs of urban soil was much higher in East China than in West China. According to the isomer ratios, about 64% of provinces and cities showed new sources of dichlorodiphenyltrichloroethane (DDT) input and dicofol input was found in 30% of China. Hexachlorocyclohexane (HCH) in urban soils was mainly derived from fresh usage of lindane (γ-HCH) in most regions of China. Lifetime carcinogenic and non-carcinogenic risks of OCPs and PCBs through ingestion, inhalation, and dermal contact indicated that PCBs in urban soils of China often exceeded safe levels. The total lifetime carcinogenic risk values of PCBs were higher than the individual lifetime acceptable risk level (10^-4) in 64% of the studied regions and the non-carcinogenic risk values exceeded the target risk level (10^-1) in 53% of the regions. The improved knowledge of the distribution and main pollution sources of POPs in urban soil of China as a result of this study can contribute to better decision-making support for soil pollution control and monitoring.

Concentrations and accumulation rates of polychlorinated biphenyls in soil along an urban-rural gradient in Shanghai

This study proposed an in situ soil experimental system to quantify concentration and accumulation rates of polychlorinated biphenyl (PCB) congeners in the soil in a rural-urban fringe and correlated them with multiple variables in the area. Variables, including road density, normalized difference vegetation index (NDVI), distance to the nearest highway and industrial area from the soil experimental sites, land-use impact index, population density, population change index (PCI), total population, and percentage of water area, were used to explain the concentration of different PCB congeners in soil during the experimental period. A proportion of 40.1%, 22.6%, 56.9%, and 34.3% accumulation rates of PCB8, PCB18, PCB28, and PCB118, respectively was explained by industrial developments, using stepwise linear regression analysis. NDVI was used to explain 33.6%, 61.5%, 49.1%, and 53.2% accumulation rates of PCB44, PCB101, PCB187, and PCB180, respectively. Filtering and transferring of airborne organic pollutants from atmosphere to soil by forests or tree stands and farmlands were all NDVI-related factors that affected the concentrations and accumulation rates of PCB congeners in soil. The traffic-related particle deposition might be the reason why the concentrations and accumulation rates of PCB congeners in soil were affected by road density. The findings can help quantitatively understand urbanization and the associated environmental effects. Graphic abstract.

Distribution of pesticides in agricultural and urban soils of Brazil: a critical review

The extensive use of pesticides leads to soil contamination and is harmful to environmental health. Brazil is considered the world's largest consumer of pesticides; however, there is no published review of the distribution and concentration of pesticides in the Brazilian soils. Thus, the objective of this study was to analyze the occurrence of pesticide residues in Brazilian soils through a systematic review of the data obtained from the official records of government agencies and scientific literature. Further, this review aims to estimate the risk quotient using the data extracted from these studies and compare it with the values from current legislation. The studies on pesticides were selected and screened, out of which 21 scientific articles were included in this review. The studies highlighted that 55 pesticides were detected in the soils in Brazil. Of these, 58% belonged to the chemical class of organochlorines and their concentration ranged from 0.0002-1243.68 mg kg-1. DDT (0.00002-1243.68 mg kg-1), HCH (0.00007-962.00 mg kg-1) and diuron (0.0031-4.16 mg kg-1) contributed to highest pesticide concentrations in soil. Residential soils had higher pesticide concentrations and greater risk factors than the agricultural soils. Moreover, 20% of the studies detected mixtures containing more than 10 types of pesticides. This study concluded that the specific scenarios evaluated by the reviewed studies do not reflect the current pesticide use and contamination in Brazil and there is a need for more information related to pesticide contamination in soils.

A national-scale characterization of organochlorine pesticides (OCPs) in intertidal sediment of China: Occurrence, fate and influential factors

Organochlorine pesticides (OCPs) have been restricted for application for about 30 years in China. Intertidal zone is a sink for anthropogenic pollutants, and to better understand the current pollution status of OCPs in China, 324 surface sediment samples collected from 14 typical intertidal zones of China were analyzed for 22 OCPs. The total concentrations of OCPs ranged from 0.051 to 4141.711 ng/g, with DDTs and HCHs being the dominant components. Seasonal variations were not significant for most intertidal zones (p > 0.05), while significant spatial variations (p < 0.05) were found among 14 intertidal zones, with the highest OCPs concentrations detected in Jiulong Jiang (JLJ). The OCPs concentrations in intertidal sediments would rarely to frequently cause adverse biological effects and DDTs were the major threat. Apart from the historical usage of technical DDT and lindane, current usage of technical DDT and HCH were also implied, especially for intertidal zones such as Beidaihe (BDH) and Yingluo Wan (YLW). PCA analysis indicated that compounds within the same type of OCPs were from similar source, while different types of OCPs were generally from different sources and not used together. Our results further indicated that OCPs together with organic particles entered into the intertidal zones mainly through river input.

Organochlorine pesticides contamination in agricultural soils of southern Iran

There is limited information about pesticide contamination in Iran's agricultural land, particularly in plains producing exportable fruits. The aim of this investigation was to evaluate the concentration of organochlorine pesticides (OCPs) including hexachlorocyclohexane (HCH), heptachlor, dichloro-diphenyl-trichloroethane (DDT), chlordane (CHL), and their isomers compounds in agricultural soils of southern Iran. A total of 28 topsoil samples were collected from agricultural lands of Dalaki and Shabankare areas, Bushehr, Iran. In Dalaki area, the mean value of ΣHCH (α, β, γ, δ), ΣDDT (o,p-DDE, o,p-DDD, o,p-DDT, p,p-DDE, p,p-DDD, p,p-DDT, and DDT), and ΣCHL (Trans-chlordane, Cis-chlordane, Heptachlor-exo-epoxide, and Heptachlor) was found to be 0.411 ng/g (dry weight, dw), 4.37 ng/g dw, and 2.04 ng/g dw, respectively. In Shabankare area the mean value of ΣHCH, ΣDDT, and ΣCHL was measured to be 1.38 ng/g dw, 11.99 ng/g dw, and 1.62 ng/g dw, respectively. The concentration trend of pesticides in both areas was as follows: DDT > CHL > HCH. Source identification indicated recent usage of HCH and DDT in the studied areas. Obtaining a cis-chlordane/trans-chlordane ratio greater than one in Shabankare farmlands showed that chlordane was not used recently. The health risk assessment showed that children and adults groups in both areas are exposed to negligible cancer risk. More serious attempts are necessary to reduce usage of OCPs during the agricultural process and the protection of soil and human health in the studied areas.

Magnetic solid phase extraction using Fe3O4@β-cyclodextrin–lipid bilayers as adsorbents followed by GC-QTOF-MS for the analysis of nine pesticides

A rapid method for the analysis of trace organochlorine pesticides in a complex matrix.

Effective biodegradation of pentachloronitrobenzene by a novel strain Peudomonas putida QTH3 isolated from contaminated soil

To eliminate pentachloronitrobenzene (PCNB) residue in PCNB-contaminated environment, the degradation potential of Pseudomonas putida QTH3 to PCNB was evaluated in this study. Peudomonas putida QTH3 could grow well in mineral salt medium (MSM) containing PCNB as sole carbon and was able to degrade PCNB efficiently, whereas the degradation rate of P. putida QTH3 to PCNB increased gradually, and reached 49.84% in 35 days. The degradation rates of P. putida QTH3 to 13 tested organochlorine compounds found to be 10.85%-42.51% after 14 days. The metabolites during PCNB biodegradation by P. putida QTH3 were identified as catechol, 2, 3, 5, 6-tetrachloroaniline (TCA), 2, 3, 4, 5- TCA, 2, 3, 4, 5, 6-pentachloroaniline (PCA) and pentachlorothioanisole (PCTAs). Furthermore, possible degradation pathway of PCNB by P. putida QTH3 was proposed. The degradation rates of intracellular enzyme and extracellular enzyme were 44.73% and 8.93% after incubation with 100 mg L^-1 PCNB for 30 min, respectively. Thus, intracellular enzyme is a major enzyme responsible for PCNB degradation. The results indicate that P. putida QTH3 can be a suitable organism for the degradation of PCNB, and facilitate its potential for the bioremediation of the environments contaminated with major organochlorine compounds used during this study.

Risk assessment of organochlorine pesticides in drinking water source of the Yangtze River

Organochlorine pesticides have been banned for many years, but the residual trace amount of organochlorine in water may still pose ecotoxicological risk. Meanwhile, the potential risk of organochlorine pesticides released from sediments, especially into drinking water sources, is receiving increasing attention. The present study assessed the pollution and potential risk of drinking water sources along the midstream and downstream Yangtze River. Residues of organochlorine pesticides (OCPs) in water, suspended particle matter (SPM), and sediment were evaluated with isotope dilution HRGC/HRMS. The results indicated that OCPs in water, SPM, and sediment ranged in 0.52-92.97 ng/L, 0.10-4.10 ng/L, and 0.038-11.36 ng/g, respectively. The predominant OCPs in water, SPM, and sediment were β-HCH, p,p'-DDE and PeCB. At site Y1, 8, 13, 18, β-HCH has a higher proportion in sediment samples, while, α-HCH has a higher proportion in SPM samples. The industrial use of HCHs in the history was the main HCHs source for most water and sediment samples, which indicated an absence of fresh inputs of industrial HCHs. Meanwhile, the abundance of p,p'-DDE in water, sediment and SPM samples could be attributed to long-term aerobic degradation of DDTs. The values of ffsw of HCHs, DDTs and PeCB indicate the transfer from water to sediment. Risk assessment showed that HCHs and DDTs posed low ecotoxicological risk to the Yangtze River.

Congener-specific composition of polychlorinated biphenyls (PCBs) in soil-air partitioning and the associated health risks

The recent changes in the compositions of polychlorinated biphenyls (PCBs) after their restriction for 40 years may have various effects on human health. In order to characterize the congener-specific compositions of PCBs in the soil-air process and assess the associated human health risks, soil and air samples were simultaneously collected in winter and summer at two different functional locations. Homologue patterns suggest that long-range atmospheric transport might be the major source of soil and air residues of PCBs. The net deposition from air to soil was overwhelming for most PCB congeners. Variations in the occurrence and the homologue patterns of PCBs between the soil and air interface depended on chemical volatility, soil organic matter (OM) content, ambient temperature, topographical condition and atmospheric transport. Dioxin-like PCBs accounted for 11.0-70.3% and 2.31-54.8% of total PCB residues in soil and air, respectively. Non-carcinogenic and carcinogenic risks associated with exposure to soil and air PCBs were also estimated. Different PCB congeners showed different health effects, with the highest contribution from PCB-26. Additionally, the non-carcinogenic risk levels of PCBs were enhanced, while the carcinogenic risk levels decreased during the soil-air exchange process of PCBs with time. Our results highlight the soil-air interaction of PCBs in predicting their potential human exposure health risks.

Organochlorine pesticides in ambient air from the littoral cities of northern China: Spatial distribution, seasonal variation, source apportionment and cancer risk assessment

Concentrations, composition and seasonal variations of organochlorine pesticides (OCPs) in the atmosphere (particulate phase and gaseous phase) at coastal cities in northern China were determined. OCP transport from emission source areas and lifetime excess cancer risks by inhalation exposure to specific OCPs were also investigated. The annual average concentration of total OCPs in gaseous phase ranged from 1.0ng/m³ to 6.3ng/m³, with the peak observed in summer at most sites. Particulate phase concentrations ranged from 29.9pg/m³ to 103.3pg/m³, with the maximum found in the local heating period at most locations. The detection rates of gaseous samples were considerably higher than those of particulate ones. The dominant components included endosulfan (I and II), (α- and γ-) chlordane, pentachlorobiphenyl (PeCB), hexachlorobenzene (HCB), heptachlor, (α-, β- and γ-) hexachlorocyclohexane (HCH), dichloro-diphenyl-trichloroethane (DDT) and their metabolic products. The specific ratios indicated different applications of DDT, technical HCH and endosulfan at most sites. Large differences in compositional profiles occurred in January (typical heating period) and July (representative non-heating period), and diurnal changes in component concentrations may have been influenced by local emission pattern. The potential source contribution function (PSCF) manifested seasonal concentrations of airborne OCPs affected by the input of potential sources in different regions. The emission sources with higher contribution probabilities to the sites were primarily distributed in the surrounding areas. The lifetime excess cancer risks for the local residents by inhalation exposure to specific components were not high, though the potential threat of α-HCH and HCB should be concerned. CAPSULE: Gaseous OCPs reached peak values in summer and dominated relative to particulate (PM₁₀) values; meanwhile, surrounding sources affected air OCP concentrations, and cancer risks of OCPs by inhalation exposure were not high.

Risk factors of stillbirth in rural China: A national cohort study

People living in rural China are more frequently exposed to some specific risk factors which made stillbirth rate higher than urban areas. National Free Preconception Health Examination Project was launched to investigate these risk factors and collected a representative sample of 248501 participants from 31 provinces in China from 2010 to 2013. Parental risk factors were ascertained twice before and during pregnancy respectively by questionnaires. Stillbirth or live birth were recorded by trained physicians. In the analysis, nested case-control study was conducted, and propensity score matching method was used to adjust the confounding. Multi-level logistic regression was used to fit for multi-level sampling. The overall stillbirth rate was 0.35% in rural China, it was higher in North (0.42%) and West (0.64%) areas. Maternal exposure to pesticide (OR (95%CI 1.06, 3.39)), hypertension (OR = 1.58 (95%CI 1.07, 2.34)), lack of appetite for vegetables (OR = 1.99 (95%CI 1.00, 3.93)), stress (compared with no pressure, OR of a little pressure was 1.34(95% CI 1.02, 1.76)); paternal exposure to smoking (OR = 1.22 (95% CI 1.02, 1.46)), organic solvents (OR = 1.64 (95% CI 1.01, 2.69)) were found independent risk factors of stillbirth. Folacin intake 3 months before pregnancy (OR = 0.72 (95%) CI 0.59, 0.89), folacin intake 1-2 months before pregnancy (OR = 0.71 (95% CI 0.55, 0.92)), folacin intake after pregnancy (OR = 0.81 (95% CI 0.65, 1.02) for) were protect factors of stillbirth. Maternal pesticide exposure, lack of vegetables, stress, paternal smoking and exposure to organic solvents were risk factors of stillbirth. Folic acid intake was protective factor of stillbirth, no matter when the intake began.