Persistent organic pollutant exposures among Greenlandic adults in relation to lifestyle and diet: New data from the ACCEPT cohort

High concentrations of persistent organic pollutants (POPs) in blood of the Greenlandic population are well known. The exposure is mainly through traditional food intake, including marine mammals and seabirds. The present study aimed to follow up on POP concentrations (organochlorine pesticides, polychlorinated biphenyls, per- and polyfluoroalkyl substances, and halogenated flame retardants (HFRs)) and relations to lifestyle and diet of the mothers included in the Greenlandic ACCEPT cohort (3-5 years after inclusion in 2013-15) and to include the children's fathers. This new data collection in 2019-20 included blood samples for measurement of POP concentrations and lifestyle and food frequency questionnaires from 101 mothers and 76 fathers aged 24-55 years living in Nuuk, Sisimiut, and Ilulissat, Greenland. The mothers' intra-individual median percentage decrease in POP concentrations from inclusion to this follow-up (3-5 years later) was 16-58%, except for mirex (0% change). Median concentrations of POPs were 1.4-4.6 times higher in fathers than in mothers. The POPs differed by residential town with generally higher concentrations in Ilulissat compared to Sisimiut and Nuuk. We report, for the first time, novel HFRs in human samples from Greenland. However, concentrations were low and only dechlorane plus (with its anti-isomer) was detected in >50% of the samples. Most POPs correlated positively with age and n-3/n-6 fatty acid ratio. The lipophilic POPs correlated positively with the percentage of life lived in Greenland, whereas few POPs correlated positively with BMI, income (personal and household), education, and alcohol intake. The POPs generally associated positively with the intake of marine mammals, seabirds, and dried fish, while few POPs associated positively with Greenlandic fish intake. In contrast, POPs generally associated negatively with imported meat products intake. The study findings may be of interest for future dietary recommendations in Greenland. We discuss the potential explanations for the findings and suggestions for future research.

Comparing total and accessible concentrations of hydrophobic organic contaminants in sediments and suspended particulate matter in the Danube River

Contamination of aquatic ecosystems by hydrophobic organic contaminants (HOCs) is often assessed based on their concentrations in riverbed sediment and suspended particulate matter (SPM). However, total HOC concentration (C_TOT) in sediment or SPM is of limited value for evaluating the exposure of benthic or pelagic organisms. The accessible HOC concentration (C_AS) presents a useful parameter quantifying the overall pool of HOC in sediment or SPM available for fast partitioning to the water phase or biota. We applied a novel approach of ex situ sequential equilibrium partitioning with silicone elastomer sampler at a high sampler/SPM phase ratio to measure C_AS of HOC in SPM from the Danube River. We compared C_TOT and C_AS in SPM and surface layer sediment collected at the same sites to evaluate whether HOC monitoring in the two matrices provides equivalent information on environmental quality. At most sites, there was a good agreement and correlation of organic carbon (OC)-normalised C_TOT in SPM and sediment for polychlorinated biphenyls (PCBs) and the majority of organochlorine pesticides (OCPs). In contrast, C_TOT of polycyclic aromatic hydrocarbons (PAHs) in SPM were up to a factor 10 lower in SPM than in sediment. Site-specific differences of OC-normalised C_AS concentrations in SPM and sediments were observed for PCBs and OCPs, with accessibility mostly lower in SPM than in sediment. The highest accessibility in SPM was observed for PCBs, ranging between 15 and 30%. The accessibility of OCPs varied from 0 to 23%. SPM and riverbed sediment samples provide complementary but not mutually interchangeable information on HOC contamination.

Evaluation of residual level and distribution characteristics of organochlorine pesticides in agricultural soils in South Korea

In this study, we evaluated the residual levels and distribution characteristics of 10 organochlorine pesticides (OCPs) in the soil of agricultural lands (paddy field, vegetable field, and orchard, n = 150) nationwide. As a result of the investigation, 3-10 types of OCPs were detected in combination in 144 locations (96%) of the total 150 locations. Among those OCPs, dichlorodiphenyltrichloroethane (DDT) and endosulfan were detected in high amounts. The geometric mean concentrations of DDT and endosulfan were ∑DDT 0.31 ng g^-1 (ND-2187.18 ng g^-1) and ∑endosulfan 0.33 ng g^-1 (ND-312.68 ng g^-1), respectively. OCP concentrations were generally higher in orchards than in other agricultural fields due to a large amount of pesticides used. DDT in two orchards was detected at 2187.18 ng g^-1 and 1061.78 ng g^-1, exceeding the levels stated in the Canadian DDT Soil Quality Guidance (SQG, 700 ng g^-1). The result of applying the isomer ratio to evaluate the recent or past use of DDT, endosulfan, and hexachlorocyclohexane (HCH), which had a high detection rate, showed that it could be attributable to historical usage. DDT and HCH showed statistically similar residual distribution patterns; however, endosulfan did not show a clear correlation with DDT and HCH due to the effect of its recent use. Thus, the results of evaluation of OCP residual levels and distribution characteristics can be used for the soil management policy of OCPs in agricultural lands in Korea.

Organochlorine pesticides in riparian soils and sediments of the middle reach of the Huaihe River: A traditional agricultural area in China

Distributions, souces, ecological risks as well as environmental behaviors of 20 organochlorine pesticides (OCPs) in riparian soils and sediments of the middle reach of the Huaihe River, a traditional agricultural area of China, were investigated. ∑OCPs in riparian soils and sediments were 1.8-63 ng g^-1 (mean = 19 ± 12 ng g^-1) and 1.2-9.9 ng g^-1 (mean = 3.0 ± 1.8 ng g^-1), respectively. HCHs were the dominant OCPs in both soils and sediments, while high concentrations of ∑HEPTs and ∑DDTs were also detected in some soils and sediments. No correlations were found between concentrations of OCPs and organic matter contents in both soils and sediments. Based on the source analysis, most OCPs in the riparian soils were mainly from historical residues, such as historical usage of technical HCH, DDT, chlordane and endosulfan. OCPs in sediments were influenced not only by surface runoff by also by other factors, e.g. in-situ contamination (DDT-containing antifouling paints in ships) and/or hydraulic transport from some tributaries. Some never-used OCPs, such as heptachlor and aldrin, were widely detected in soils and sediments. This might be attributed to some unknown usages or long-range atmospheric transport of them from other source regions. Ecological risk analysis suggested that DDTs and HCHs in soils would not lead to an adverse effect on soil ecological environment as well as agricultural production, and OCP residues in sediments also would not pose a threat to the sediment-dwelling organisms.

Prenatal and childhood exposure to chlordecone and adiposity of seven-year-old children in the Timoun mother-child cohort study in Guadeloupe (French West Indies)

BACKGROUND

Exposure to persistent environmental organic pollutants may contribute to the development of obesity among children. Chlordecone is a persistent organochlorine insecticide with estrogenic properties that was used in the French West Indies (1973-1993) and is still present in the soil and the water and food consumed by the local population. We studied the association between prenatal and childhood exposure to chlordecone and the adiposity of prepubertal children.

METHODS

Within the Timoun Mother-Child Cohort Study in Guadeloupe (French West Indies), 575 children had a medical examination at seven years of age, including adiposity measurements. A Structural Equation Modeling approach was used to create a global adiposity score from four adiposity indicators: the BMI z-score, percentage of fat mass, sum of the tricipital and subscapular skinfold thickness, and waist-to-height ratio. Chlordecone concentrations were measured in cord blood at birth and in the children's blood at seven years of age. Models were adjusted for prenatal and postnatal covariates. Sensitivity analyses accounted for co-exposure to PCB-153 and pp'-DDE. Mediation analyses, including intermediate birth outcomes, were conducted.

RESULTS

Prenatal chlordecone exposure tended to be associated with increased adiposity at seven years of age, particularly in boys. However, statistical significance was only reached in the third quartile of exposure and neither linear nor non-linear trends could be formally identified. Consideration of preterm birth or birth weight in mediation analyses did not modify the results, as adjustment for PCB-153 and pp'-DDE co-exposures.

CONCLUSION

Globally, we found little evidence of an association between chlordecone exposure during the critical in utero or childhood periods of development and altered body-weight homeostasis in childhood. Nevertheless, some associations we observed at seven years of age, although non-significant, were consistent with those observed at earlier ages and would be worth investing during further follow-ups of children of the Timoun Mother-Child Cohort Study when they reach puberty.

Bioaccumulation of organochlorine pesticides in Antarctic krill (Euphausia superba): Profile, influencing factors, and mechanisms

Accumulation of organochlorine pesticides (OCPs) in Antarctic krill (Euphausia superba), a keystone species in the Southern Ocean, is potentially harmful to the Antarctic ecosystem and human health. In the current study, we collected E. superba specimens (including muscle and carapace tissues) from Bransfield Strait in northern Antarctic Peninsula and South Georgia to analyze the profile, influencing factors and mechanisms of OCPs bioaccumulation in them. Results indicated that the biological traits (δ¹³C, δ¹⁵N and lipid contents) of krill were significantly affected by habitat. There may exist growth dilution of OCPs in Antarctic krill and no fresh OCPs input in Antarctica, except for endosulfan I. Based on lipid-normalized concentrations, no significant differences were observed between the two regions at most sampling sites. However, OCP levels showed tissue and sex dependence. Boosted regression trees (BRTs) and partial least squares structural equation models (PLS-SEMs) were built to better investigate the main factors affecting the bioaccumulation of OCPs. Lipid content, negatively correlated with OCP levels, was the main factor. In vitro silicon modeling indicated that CYP3A4 metabolism capacity in krill contributed to the OCP residues except for endosulfan I. The results of this study expand current knowledge of OCPs in Antarctic marine biota, as well as their influencing factors and potential mechanisms.

Persistent and toxic chemical pollutants in fish consumed by Asians in Chicago, United States

Consumption of seafood brings health benefits but may increase the ingestion of contaminants. Compared with other ethnic groups in the U.S., Asians consume seafood more frequently. However, there is little information about how culturally specific fish consumption contributes to exposure to toxicants. In this work, we surveyed fish consumption among Chinese, Korean and Vietnamese communities and purchased 103 seafood samples from local markets in Chicago. Each sample was analyzed for mercury (Hg) and 92 organic chemicals including polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), polybrominated diphenyl ethers (PBDEs), and Dechlorane Plus and related compounds (DPs). The rank order of pollutant concentration in all samples was Hg ≫ Σ₆₆PCBs > Σ₁₇OCPs > Σ₈PBDEs > Σ₈DPs. Positive correlations were noted among most contaminant groups. Bluefish, pike and tuna steak had the highest mean Hg (>1 mg/kg). The mean Σ₆₆PCBs was highest in pike and bluefish (>100 ng/g) followed by pollock and mackerel (>40 ng/g). Overall, octopus, shrimp and tilapia were the least contaminated; while pike, bluefish, and pollock were the most contaminated. Omega-3 fatty acids were more strongly affiliated with the organic contaminants than mercury. A risk assessment identified seven types of fish that should have consumption limitations and six that should not be consumed. For these seafoods, consumption advice based on Hg levels would adequately protect health. In the survey participants, 17% of seafood mass consumed is from types of fish that should be limited to 1 or 2 meals/week, while 7% of the seafood mass consumed comes from types that should not be consumed at all. This work adds additional contaminants to the profile of health risks resulting from fish consumption among Asian Americans, which can be used in interventions aimed at conserving consumption of healthy fish while avoiding contaminants.

Assessment of genotoxicity and oxidative stress in pregnant women contaminated to organochlorine pesticides and its correlation with pregnancy outcome

The present study was aimed to assess the correlation between transplacental transfer of xenobiotics and resulting biochemical alterations (including genotoxicity and oxidative stress) in non-occupational pregnant women of North India along with the effect on pregnancy outcomes. Maternal and cord blood samples were collected from 221 healthy mother-infant couples and divided according to their gestational age and birth weight. Genotoxic effects in mother and cord blood were examined using comet assay. The quantitative determination of Organo-chlorine pesticides in blood serum of study population was carried out using gas chromatography-mass spectrometry (GC-MS). Notably higher Organo-chlorine pesticides levels were observed in maternal blood of preterm than term subjects for almost all of the compounds detected, with the maximum concentration found for aldrin (3.26 mg/l) in maternal blood and dieldrin (2.69 mg/l) in cord blood. The results showed a significant increment in olive tail moment, tail full length, catalase, super-oxide dismutase, and malondialdehyde levels whereas lower glutathione reductase and peroxidase were found in preterm babies when compared with term group and it varied in the order: maternal blood > cord blood. A clear trend was observed for preterm babies with their lower birth weight and cesarean mode of delivery. Therefore, reduction in birth weight in newborns may be the consequence of increased oxidative damage and genotoxicity brought about by pesticides and these markers could be employed for early detection of pesticides related ailments and toxicities. To the best of our knowledge, this was a pioneering study and it may help to increase our knowledge with regard to xenobiotic exposure in biological system and the need for stringent guidelines for agricultural use of pesticides.

Concentrations and Human Health Risk of Organochlorines in Farmed Freshwater Products: Fish Ponds around Changsha, China

ABSTRACT

The present study was conducted to reveal the concentrations and patterns of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in seven species of freshwater food products (Procambarus clarkii, Ctenopharyngodon idellus, Parabramis pekinensis, Hypophthalmichthys molitrix, Cyprinus carpio, Aristichthys nobilis, and Carassius auratus) collected from aquaculture farms around Changsha, People's Republic of China. The OCPs and PCBs in the muscle tissue of these species were analyzed to assess the health risk associated with dietary intake. The mean concentrations of OCPs and PCBs were 6.38 to 15.90 and 3.18 to 5.12 ng g-1 wet weight, respectively. Heptachlor and δ-HCH were the main OCP contaminants in the tested samples, accounting for >74% of the total OCPs. PCB52 was the main PCB, accounting for >88% of the total PCBs. The bioaccumulation of OCPs and PCBs in these aquatic products depends upon the species. C. idellus had the highest concentrations of OCPs, and H. molitrix had the highest concentrations of PCBs. The mean lipid concentration in these freshwater species was 6.08 to 19.8% (dry weight) and was significantly correlated with the concentrations of OCPs and PCBs. The health risk from consumption of these freshwater species was assessed based on the hazard ratios and hazard quotient, and consumption of these products was determined to pose a carcinogenic risk.

HIGHLIGHTS

Monitoring temporal trends of dioxins, organochlorine pesticides and chlorinated paraffins in pooled serum samples collected from Northern Norwegian women: The MISA cohort study

The ubiquitous presence of legacy and emerging persistent organic pollutants (POPs) in the environmental matrices poses a potential hazard to the humans and creating public health concerns. The present study aimed to evaluate dioxins, dioxin-like polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs) and chlorinated paraffins (CPs) concentrations in serum of women (postpartum, pregnant and non-pregnant) from Northern Norway to better understand their exposure and contamination status as well as temporal trends across 2007-2009 (MISA 1) to 2019 (MISA 2). Sixty-two blood samples from the MISA 1 cohort and 38 samples from MISA 2 were randomly selected in this study (n = 100). Ninety samples from postpartum (MISA 1) and pregnant women (MISA 2) were randomly combined into 9 pools, with 9-11 individual samples contributing to each pool keeping the groups of pregnant and postpartum women. Remaining 10 samples from non-pregnant women (MISA 2) were allocated into separate group. Geometric mean, minimum and maximum were used to describe the serum concentrations of pooled POPs in MISA cohort. Mann-Whitney U test and independent sample t-test were applied for trend analysis of blood levels of POPs between MISA 1 and MISA 2. We found the serum concentrations of selected POPs in this study to be at lower range. Serum concentrations of dibenzo-p-dioxins (PCDDs) (p = 0.010), polychlorinated dibenzofurans (PCDFs) (p = 0.002), dioxins-like PCBs (p = 0.001), hexachlorobenzene (HCB) (p < 0.001) and p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) (p = 0.002) were decreased between the studied time. In contrast, the serum concentrations of medium chain chlorinated paraffins showed an increasing trend between 2007 and 2009 and 2019 (p = 0.019). Our findings report a particular concern of emerging contaminant medium chain chlorinated paraffin exposure to humans. Future observational studies with repeated measurements of chlorinated paraffins in general populations worldwide and large sample size are warranted.

Trace metals and organochlorine pesticide residues in imported fishes in Bangladesh and human health risk implications

Substantial quantity of fish has been imported to Bangladesh without adequate food safety assessment which can pose a serious health risk to local people. This study analyzed the trace metals and organochlorine pesticides residues and the associated human health risk in 33 imported fishes (9 species) from four countries (India, Myanmar, Oman, and United Arab Emirates) collected from three different ports (Benapole, Bhomra, and Chittagong) of Bangladesh with invoice lists from the port authorities. Trace metal concentrations were determined using graphite furnace absorption spectrometry and flame absorption spectrometry. The two organochlorine pesticides (Aldrin and Chlordane) residues were determined by GC-MS and found as below detection level (BDL). The trace metal concentrations (mg/kg-ww) in imported fish samples ranged as As 0.008 to 0.558, Pb 0.004 to 0.070, Cr 0.010 to 0.109, Cd 0.00 to 0.083, Ni 0.011 to 0.059, Co BDL to 0.067, Mn BDL to 0.0780, Fe 1.780 to 10.77, Cu 0.055 to 0.632, and Zn 0.898 to 9.245. Concentrations of As and Cd were higher than the food safety guideline. Considering the source country of imported fishes, fish samples from Oman were mostly contaminated by the trace metals. The estimated daily intake (EDI) was higher for Cr. However, the target hazard quotient (THQ) for individual metal and total THQ for combined metals were lower than 1, indicating no apparent non-carcinogenic health risk for consumers. The cancer risk (CR) was within the acceptable range. But extensive monitoring of these toxic chemicals is needed prior to import these fishes to the country. Given the self-sufficiency in fish production, this study also argues whether Bangladesh needs to import the fishes at all.

Organochlorine pesticides and chlorpyrifos in the sea anemone Bunodosoma zamponii (Actiniaria: Actiniidae) from Argentina's southeastern coast

Temporal and spatial distribution of organochlorine pesticides (OCPs) and the organophosphate pesticide chlorpyrifos, one of the main insecticides used in Argentina, was evaluated in two populations of the sea anemone Bunodosoma zamponii living under different anthropological stressors: Las Delicias (LD) adjacent to a wastewater plant, and Punta Cantera (PC) a reference site. Pesticides were analyzed throughout the year in water, sediments and whole organisms. Chlorpyrifos represented 50% of the total pesticide found in water samples during winter. HCHs and drins were predominant in sediment samples, mainly in LD. Total pesticide concentration in anemones from LD was higher than those from PC during winter (mainly associated with HCHs, endosulfans, DDTs and chlorpyrifos levels), coincident with the main period of effluent discharge to the coast after pesticide applications and also the rainiest season. Dissimilarities among anemones populations could stem from a differential input of pesticides in each site and/or a contrasting physiological status of the populations.

Vertical distribution and effect of historical residual organochlorine pesticides on microbial community structure in sediment cores from an abandoned oxidation pond after dredging for 15 years

The vertical distribution pattern of 19 organochlorine pesticides (OCPs), together with microbial ester-linked fatty acid methyl ester (EL-FAME) profiles were investigated in sediments from an abandoned oxidation pond of Ya-Er lake, China, which had been heavily polluted by hexachlorocyclohexanes (HCHs) and chlorobenzenes in 1980s. Subsurface sediment samples were taken from five sediment cores along the transect running from the lakeshore (0.5~2.7 m in depth) to lakebed (0.1~0.4 m). The total OCP concentration ranged from 29.8 to 941.8 ng g^-1 dw. Hexachlorobenzene (HCB), HCHs, and dichlorodiphenyl-trichloroethanes (DDTs) were the three dominant OCP classes, accounting for 26.5-97.4%, 1.8-33.2%, and 0.4-15.5% of the total OCP concentration, respectively. Hot spots of HCB, HCHs, and DDTs were detected at 0.9~2.7 m deep layers of the lakeshore, where was once the main dredged sediment backfill site for in-situ remediation of the oxidation pond in 2002-2004. HCHs and HCB still showed high potential ecological risks. The sources of OCPs were identified and quantified using principal component analysis with absolute principal component scores-multiple linear regression model. The first three major sources were persistent residues, recent agricultural input, and historical industrial input, contributing on average 28.2%, 17.9%, and 17.1% of total OCPs, respectively. Redundancy analysis of microbial EL-FAME profiles and nine dominant OCPs revealed that the spatial variation in microbial community structure was significantly corresponded with the OCP composition. This is the first study highlighting the concern on historical industrial inputs of OCPs in subsurface sediments of the lakeshore disposal zone. The findings could help to distinguish the artificial backfill sediments from undisturbed polluted sediments for optimization of further dredging plans.

Removal of organochlorine pesticides using zerovalent iron supported on biochar nanocomposite from Nephelium lappaceum (Rambutan) fruit peel waste

Unique zerovalent iron (Fe⁰) supported on biochar nanocomposite (Fe⁰-B_RtP) was synthesized from Nephelium lappaceum (Rambutan) fruit peel waste and were applied for the simultaneous removal of 6 selected organochlorine pesticides (OCPs) from aqueous medium. During facile synthesis of Fe⁰-B_RtP, Rambutan peel extract was used as the green reducing mediator to reduce Fe²⁺ to zerovalent iron (Fe⁰), instead of toxic sodium borohydride which were used for chemical synthesis. For comparison, chemically synthesized Fe⁰-B_Che nanocomposite was also prepared in this work. Characterization study confirmed the successful synthesis and dispersion of Fe⁰ nanoparticles on biochar surface. Batch experiments revealed that Fe⁰-B_RtP and Fe⁰-B_Che nanocomposites combine the advantage of adsorption and dechlorination of OCPs in aqueous medium and up to 96-99% and 83-91% removal was obtained within 120 and 150 min, respectively at initial pH 4. Nevertheless, the reactivity of Fe⁰-B_Che nanocomposite decreased 2 folds after being aged in air for one month, whilst Fe⁰-B_RtP almost remained the same. Adsorption isotherm of OCPs were fitted well to Langmuir isotherm and then to Freundlich isotherm. The experimental kinetic data were fitted first to pseudo-second-order adsorption kinetic model and then to pseudo-first-order reduction kinetic model. The adsorption mechanism involves π-π electron-donor-acceptor interaction and adsorption is facilitated by the hydrophobic sorption and pore filling. After being reused five times, the removal efficiency of regenerated Fe⁰-B_Che and Fe⁰-B_RtP was 5-13% and 89-92%, respectively. The application of this Fe⁰-B_RtP nanocomposite could represent a green and low-cost potential material for adsorption and subsequent reduction of OCPs in aquatic system.

Seasonal variations in air concentrations of 27 organochlorine pesticides (OCPs) and 25 current-use pesticides (CUPs) across three agricultural areas of South Africa

For decades pesticides have been used in agriculture, however, the occurrence of legacy organochlorine pesticides (OCPs) and current-use pesticides (CUPs) is poorly understood in Africa. This study investigates air concentrations of OCPs and CUPs in three South African agricultural areas, their spatial/seasonal variations and mixture profiles. Between 2017 and 2018, 54 polyurethane foam-disks passive air-samplers (PUF-PAS) were positioned in three agricultural areas of the Western Cape, producing mainly apples, table grapes and wheat. Within areas, 25 CUPs were measured at two sites (farm and village), and 27 OCPs at one site (farm). Kruskal-Wallis tests investigated area differences in OCPs concentrations, and linear mixed-effect models studied differences in CUPs concentrations between areas, sites and sampling rounds. In total, 20 OCPs and 16 CUPs were detected. A median of 16 OCPs and 10 CUPs were detected per sample, making a total of 11 OCPs and 24 CUPs combinations. Eight OCPs (trans-chlordane, o,p'-/p,p'-dichlorodiphenyldichloroethylene (DDE)/dichlorodiphenyltrichloroethane (DDT), endosulfan sulfate, γ-hexachlorocyclohexane and mirex) and two CUPs (carbaryl and chlorpyrifos) were quantified in all samples. p,p'-DDE (median 0.14 ng/m³) and chlorpyrifos (median 0.70 ng/m³) showed the highest concentrations throughout the study. Several OCPs and CUPs showed different concentrations between areas and seasons, although CUPs concentrations did not differ between sites. OCPs ratios suggest ongoing chlordane use in the region, while DDT and endosulfan contamination result from past-use. Our study revealed spatial and seasonal variations of different OCPs and CUPs combinations detected in air. Further studies are needed to investigate the potential cumulative or synergistic risks of the detected pesticides.

How can environmental conditions influence dicofol genotoxicity on the edible Asiatic clam, Meretrix meretrix?

Genotoxic effects of dicofol on the edible clam Meretrix meretrix were investigated through a mesocosm experiment. Individuals of M. meretrix, were exposed to environmental concentration (D1 = 50 ng/L) and supra-environmental concentration (D2 = 500 ng/L) of dicofol for 15 days, followed by the same depuration period. DNA damage (i.e., strand breaks and alkali-labile sites) was evaluated at day 1, 7 and 15, during uptake and depuration, using Comet assay (alkaline version) and nuclear abnormalities (NAs) as genotoxicity biomarkers. The protective effects of dicofol against DNA damage induced by ex vivo hydrogen peroxide (H₂O₂) exposure were also assessed. Comet assay results revealed no significant DNA damages under dicofol exposure, indicating 1) apparent lack of genotoxicity of dicofol to the tested conditions and/or 2) resistance of the animals due to optimal adaptation to stress conditions. Moreover, ex vivo H₂O₂ exposure showed an increase in the DNA damage in all the treatments without significant differences between them. However, considering only the DNA damage induced by H₂O₂ during uptake phase, D1 animals had significantly lower DNA damage than those from other treatments, revealing higher protection against a second stressor. NAs data showed a decrease in the % of cells with polymorphic, kidney shape, notched or lobbed nucleus, along the experiment. The combination of these results supports the idea that the clams used in the experiment were probably collected from a stressful environment (in this case Pearl River Delta region) which could have triggered some degree of adaptation to those environmental conditions, explaining the lack of DNA damages and highlighting the importance of organisms' origin and the conditions that they were exposed during their lives.

Mesoporous silica sorbent with gold nanoparticles for solid-phase extraction of organochlorine pesticides in water samples

In this work, a novel sorbent, based on UVM-7 mesoporous silica doped with Au, has been proposed for organochlorine pesticides extraction. Cartridges containing this material have been applied to the preconcentration of 20 pesticides from water samples, through a solid-phase extraction (SPE) protocol, with their later determination by gas chromatography with an electron capture detector. First, UVM-7 materials were properly characterized by X-ray diffraction, N₂ adsorption-desorption, electron microscopy techniques, and UV-Vis spectroscopy, thus confirming their structure and Au incorporation. After optimization of main extraction parameters, recoveries in the range of 80-110% were obtained for most of the analytes, with enrichment factors comprised between 275 and 430. The obtained sensitivity was comparable with other reported methods, with limits of quantification in the range of 0.3-20 ng L^-1, thus allowing the determination of these compounds according to European legislation. The developed method has been successfully applied to the analysis of real spiked samples in comparison with a reference method, thus being this sorbent an alternative for organochlorine pesticide enrichment, through a simple, reusable, cheap, and environmentally friendly SPE procedure.

Relationship between thyroid hormone parameters and exposure to a mixture of organochlorine pesticides, mercury and nutrients in the cord blood of newborns

The fetus is prenatally exposed to a mixture of organochlorine pesticides (OCPs), mercury (Hg), docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA) and selenium (Se) through maternal seafood consumption in real-life scenario. Prenatal exposure to these contaminants and nutrients has been suggested to affect thyroid hormone (TH) status in newborns, but the potential relationships between them are unclear and the joint effects of the mixture are seldom analyzed. The aim of the study is to investigate the associations of prenatal exposure to a mixture of OCPs, Hg, DHA, EPA and Se with TH parameters in newborns. 228 mother-infant pairs in Shanghai, China were included. We measured 20 OCPs, total Hg, DHA, EPA and Se in cord blood samples as exposure variables. The total thyroxine (TT4), free thyroxine (FT4), total triiodothyronine (TT3), free triiodothyronine (FT3), and thyroid-stimulating hormone (TSH) levels and the FT3/FT4 ratio in cord serum were determined as outcomes. Using linear regression models, generalized additive models and Bayesian kernel machine regression, we found dose-response relationships of the mixture component with outcomes: among the contaminants, p,p'-DDE was the most important positive predictor of TT3, while HCB was predominantly positively associated with FT3 and the FT3/FT4 ratio, indicating different mechanisms underlying these relationships; among the nutrients, EPA was first found to be positively related to the FT3/FT4 ratio. Additionally, we found suggestive evidence of interactions between p,p'-DDE and HCB on both TT3 and FT3, and EPA by HCB interactions for TT3, FT3 and FT3/FT4 ratio. However, the overall effects of the mixture on thyroid hormone parameters were not significant. Our result suggests that prenatal exposure to p,p'-DDE, HCB and EPA as part of a mixture might affect thyroid function of newborns in independent and interactive ways. The potential biological mechanisms merit further investigation.

Low levels of persistent organic pollutants in sediments of the Doce River mouth, South Atlantic, before the Fundão dam failure

The Doce River mouth (DRM) was severely impacted by the rupture of the Fundão Dam in 2015, considered the greatest Brazilian environmental tragedy in terms of tailings volume released (>40 million m³) and traveled distance (~600 km until the Atlantic Ocean). Environmental monitoring has been performed since then, but background levels are scarce or absent to Persistent Organic Pollutants (POPs), making impact assessments difficult. In the current study, we presented the baseline levels, inventories, and risk assessment of the POPs polychlorinated biphenyl (PCBs) and organochlorinated pesticides (OCPs), in surface sediment of the DRM. Samples were collected in December 2010 and July 2011, i.e., four years before the Fundão dam failure. The total PCBs and the OCPs (Aldrin, HCHs, and Chlordanes) were detected in both sampling campaigns, with levels up to 9.50 and 1.64, 0.28, and 0.63 ng g^-1, respectively. The decrease of the Doce River flow was the main factor contributing to seasonal variations in the spatial distribution, and to a slight decline in the levels and frequency of the analyzed POPs in sediments collected in the dry season (July 2011). Environmental risk assessment, inventories, and total mass results suggest a low potential of PCBs and OCPs accumulation before the dam failure. This is the first POPs assessment in the study area that helped identify some unexpected impacts of the Fundão dam failure and contributed to the understanding of POPs cycles in the Southern Atlantic, data that are still scarce in the region.

Biomonitoring of toxic metals, organochlorine pesticides, and polybrominated biphenyl 153 in Michigan urban anglers

The 32-mile Detroit River and surrounding tributaries have been designated as a Great Lakes Area of Concern due to pollution from decades of municipal and industrial discharges, sewer overflows and urban development. The Agency for Toxic Substances and Disease Registry and the Michigan Department of Health and Human Services conducted a biomonitoring study to assess exposures to persistent toxic substances in Detroit urban shoreline anglers who may be at high exposure risk due to consumption of locally caught fish. Using a modified venue-based sampling approach, 287 adult shoreline anglers along the Detroit River were recruited and participated in the program. Study participants provided blood and urine specimens and completed a questionnaire interview. In this report, we examine percentile estimates for blood lead, blood manganese, urine arsenic, urine mercury, urine cadmium, organochlorine pesticides in serum (mirex, hexachlorobenzene, chlordane), and serum polybrominated biphenyl 153 (PBB 153) concentrations among study participants. Multiple linear regression was used to identify predictors of contaminant concentrations. The Detroit urban anglers' blood lead concentrations were 2 times higher than the general adult U.S. population (median (95% CI): 2.9 μg/dL (1.8-2.3) vs. 0.94 μg/dL (0.90-0.98)). PBB 153 levels were 1.8 times higher than the general adult U.S. population at the 95th percentile (95th percentile, 95% CI: 62.7 ng/g of lipid, 53.2-75.2 vs. 34.6 ng/g of lipid, 12.8-66.8). Percentile estimates of the other study pollutants were similar to background levels found in the general U.S. population. Eating more locally caught fish was not associated with increased body burdens for any of the contaminants examined in this report. Higher blood lead was associated with increased age, male sex, current smoking, residing in a home built before 1960, an annual income less than $25,000, and a work history of lead paint removal. Evidence of PBB exposure in our study cohort likely reflects the continued effect of a widespread contamination of livestock feed in 1973 among Michigan's lower peninsula population. These study results help determine if the pollutants examined warrant further consideration in subsequent population-based biomonitoring of frequent consumers of fish from the Detroit River and surrounding waterways. The biomonitoring data from this study also served to inform public health officials regarding the potential need for environmental public health actions to reduce harmful exposures.

Polychlorinated biphenyls and organochlorine pesticides in breast milk samples and their correlation with dietary and reproductive factors in lactating mothers in Istanbul

Persistent organic pollutants (POPs) continue to threaten the environment and human health. We have investigated levels of polychlorinated biphenyls (PCBs) and organochlorinated pesticides (OCPs) in breast milk samples. A questionnaire was also obtained from the study participants. A total of 48 healthy lactating mothers (mean age: 29.5±0.8 years) living in Istanbul volunteered to participate in this study. High-resolution analyses of several OCPs and PCB congeners were done by gas chromatography. The levels of seven major PCB congeners (28, 52, 101, 118, 138, 153, and 180) and eight OCPs (α-benzenehexachloride, β-benzenehexachloride, δ-benzenehexachloride, hexachlorobenzene (HCB), and 2,4'-dichlorodiphenyldichloroethylene (2,4DDE), 4,4'-dichlorodiphenyldichloroethylene (4,4DDE), 2,4'-dichlorodiphenyltrichloroethane (2,4DDT), and 4,4'-dichlorodiphenyltrichloroethane (4,4DDT)) were determined. The analysis showed that the highest levels of PCBs were observed in PCB 52 (22.99±8.78 ng/g lipid), PCB 101 (12.22±7.8 ng/g lipid), PCB 28 (11.44±5.16 ng/g lipid), and PCB 153 (1.70±0.74 ng/g lipid). The highest OCPs detected were 4,4DDT (3.33±2.05 ng/g lipid) and 4,4DDE (0.86 ± 0.39 ng/g lipid), and the lowest was observed in HCB (0.016 ± 0.01 ng/g lipid). Our findings show that traces of PCBs and OCPs are still present in breast milk of lactating women living in Istanbul, and these pollutants decline in multipara women compared to primipara mothers. We also suggest that breast milk is a useful and representative biological tool for human biomonitoring of POPs.

Trends of banned pesticides and PCBs in different tissues of striped dolphins (Stenella coeruleoalba) stranded in the Northwestern Mediterranean reflect changing contamination patterns

Although banned for years, organochlorine pesticides and PCBs continue to affect aquatic life, dolphins being particularly exposed. The concentrations of 31 PCB congeners, and 15 banned pesticides or metabolites were measured in 5 tissues of 68 striped dolphins stranded in the Northwestern Mediterranean coast in 2010-16. The results were compared to historical data (1988-2009) and, even though there is a slow decreasing trend, the levels in the 2010-2016 samples were still elevated based on common cetacean toxicological thresholds. A transition period in 2007-08, probably caused by a morbillivirus epizootic amplified the stranding, espacially of highly contaminated specimens. From 2010, higher proportions in parent compounds towards metabolites were observed yet again. These changing patterns were likely reflect the exposure of dolphins to the remobilization of pollutants from contaminated soils and sediments, with a prominent role of rivers. This should lead to an even slower decline of these contaminants that could last for decades, requiring new efforts to reduce their dispersal to aquatic ecosystems.

Organochlorine pesticides, polycyclic aromatic hydrocarbons, metals and metalloids in microplastics found in regurgitated pellets of black vulture from Campeche, Mexico

Plastics are produced by the millions of tons worldwide each year, with their final deposition in landfills (LFs). Plastics deposited in LFs can fragment over time, giving rise to mesoplastics and later to microplastics (MPs), in which toxic chemicals such as heavy metals, organochlorine pesticides, and polycyclic aromatic hydrocarbons can adhere. MPs can be vectors for the exposure to pollutants of black vultures (Coragyps atratus) due to feeding in LFs, resulting in accidental ingestion of MPs. It is also possible that MPs can adsorb pollutants from vultures during the digestion process. The aim of this study was to estimate the risk of black vulture exposure to MPs, heavy metals (HMs), organochlorine pesticides (OCPs) and polycyclic aromatic hydrocarbons (PAHs). Fifty-eight black vulture pellets were collected at the Campeche LF during 2019 (n = 24) and 2020 (n = 34). The pellets, on average, had an MP load per pellet of 6.7 ± 5.8 MPs/total pellets. The greatest abundance of MPs was detected in 2019, with 225 particles in total. The concentrations of Cd, Pb, Cu, Cr, Hg, As, and Al were detected in the MPs, with the greatest average concentration of 35.59 ± 32.39 μg·g^-1 (2019) and 15.82 ± 17.47 μg·g^-1 (2020) for Al. In 2020, ∑endosulfans were present in all MPs at 0.97 ± 1.47 ng·g^-1. Among the PAHs, 15 of the 16 compounds indicated as priorities by the US EPA were quantified. The compound with the greatest total concentration for both years was acenaphthylene (3 rings), with 10.51 ± 7.88 ng·g^-1 (2019) and 10.61 ± 18 ng·g^-1 (2020). More research is needed regarding the origin of the contaminants detected in the MPs extracted from the pellets, since the contaminants may come from the environment or possibly from the digestion processes in the stomach of avian raptors and scavengers.

Distribution and flux of organochlorine pesticides in sediment from Prydz Bay, Antarctic: Implication of sources and trends

Surface sediments were collected from Prydz Bay, Antarctica to investigate the distribution patterns, origins, annual fluxes, and trends of organochlorine pesticides (OCPs) in the marginal sea of polar areas. The concentrations of OCPs ranged from 0.80 to 7.90 ng/g dry weight, with dichlorodiphenytrichloroethanes (DDTs) as the main components. Levels of hexachlorocyclohexanes (HCHs) and DDTs in sediment from Prydz Bay were comparable to the majority of marine sediment worldwide. The distributions of OCPs were characterized by a distinct "quasi-concentric circle" pattern, which has significantly positive relationship with total organic carbon (TOC) of sediment and controlled by the local hydrodynamic conditions and sources of organic matter. Source apportionment demonstrated that HCHs and chlordanes in Prydz Bay were mainly derived from the long range atmospheric transport (LRAT) of these compounds from off regions. However, current inputs of DDT-based compounds and lindane are suggested to exist either as a result of the LART from the neighbouring countries or re-emission from melting glacier. The annual sedimentary fluxes of OCPs were 0.007 to 7.12 pg/cm²/yr, about one to three orders of magnitude lower than some data from the Arctic areas. Based on a rough calculation of r-HCH, only 0.3-1.5% of the air-seawater net deposition would be buried in sediment, implying a long active lifetime of OCPs in Antarctica. We preliminarily indicate an increase of OCP contamination in Antarctic environment afterwards when considering the possible occurrence of "fresh" sources and low proportion of sedimentary sink.

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.