Legacy halogenated organic pollutants, including organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs), remain ubiquitous in the environment and continue to pose potential (eco-)toxicological threats because of their ongoing releases from land-based sources. This study investigated the spatial trends of freely dissolved PCBs and OCPs by polyethylene passive samplers, and provided evidence of their land-use-based sources and ecological risk in an urbanized estuary area of Narragansett Bay. Dissolved Σ₂₉PCB concentrations ranged from 0.01 to 1.37 ng L⁻¹, and exhibited higher concentrations in the upper, more urban/built-up watershed, and in north coastal areas. Major inputs of PCBs were urban stormwater or treated wastewater that might carry past releases of Aroclors, pigment manufacturing byproducts, and volatilization-associated PCBs from ageing buildings from the Narragansett watershed to the bay. The dioxin toxicity equivalent values of Σ₅PCBs were 8.6E-03 pg L⁻¹ in water. Dissolved OCP concentrations had similar spatial trends to PCBs and were dominated by DDTs (average 230 pg L⁻¹), followed by chlordanes (average 230 pg L⁻¹), and HCB (average 22 pg L⁻¹). Secondary sources of past usage and historic contamination were expected to re-enter the surface water via atmospheric transport and deposition. The risk quotients of DDE, DDD, DDT and α-Endosulfane showed medium to high ecological risks in the northern area, while chlordane, HCB, oxychlordane, and heptachlor epoxide showed low to negligible risks in all zones. This study presented new insights into the presence, sources and transport of legacy halogenated organic contaminants in an urban estuary's watershed by combining passive samplers and geographic information system (GIS) technology. The approach is promising and could be extended to get better understand of terrestrial pollutant mobilization into estuaries affected by anthropogenic activities.

Agricultural use of organochlorine pesticides (OCPs) increased during the twentieth century but many of them have been progressively banned several decades after their introduction. Nevertheless, these lipophilic chemical compounds may persist in soils and sediments. From sediment deposits, it is possible to reconstruct the chronology of OCP releases in relation to former applications through time. Nevertheless, long-term fate of OCPs i.e. source, transfer, and storage through the watershed, is also related to the OCPs-sediment characteristics interactions, and our study showed the significant links between OCPs and labile or refractory organic matter. From sediment cores collected in a mainly agricultural watershed, the Eure River watershed (France), aldrin and lindane widespread applications during the 1950s–1970s have been recorded. While lindane applications declined after that date, according to the temporal trend of the stable isomer of hexachlorocyclohexane (β-HCH), α-, and γ-HCH have been recorded at significant levels in the 2000s, suggesting first local post-ban applications. Nevertheless, the relationships between these OCPs and labile organic matter resulted in an overestimation of the post-ban releases. Also, the detection of stable metabolites of dichlorodiphenyltrichloroethane (DDT) (i.e. 4,4′-DDE) and heptachlor (i.e. heptachlor epoxide) several decades after their ban, revealed the role of old deep soils erosion in the chronology of OCP releases and thus the reemergence of stable transformation products from historical OCPs.

Studies have documented that exposure to organochlorine pesticides (OCPs) is linked with breast cancer, but the underlying biological mechanisms are still unknown. This study included 313 women diagnosed with breast cancer and 313 controls in Wuhan, China, and measured 18 OCPs in serum and 3 oxidative stress biomarkers in urine. Multivariable adjusted regression models were used to evaluate the associations among OCPs, oxidative stress biomarkers, and breast cancer. The mediating effect of oxidative stress was assessed by mediation analysis. We observed that most OCPs were positively associated with risk of breast cancer (all FDR-P values < 0.05 or 0.10). Moreover, we found that p,p'-DDT, p,p'-DDD, dieldrin, heptachlor, and heptachlor epoxide were positively associated with 4-hydroxy-2-nonenal-mercapturic acid (HNE-MA) and 8-iso-prostaglandin F₂α (8-isoPGF₂α), which in turn were positively associated with risk of breast cancer. Mediation analysis indicated that HNE-MA and 8-isoPGF₂ɑ mediated the positive associations between these OCPs and risk of breast cancer, with mediating proportion ranging from 6.23% to 19.9%. Our results suggest that lipid peroxidation may mediate the positive associations between OCP exposures and risk of breast cancer.

Batoids (Chondrichthyes: Batoidea; e.g. stingrays, skates, and guitarfish) comprise more than 55% of elasmobranch taxa and represent ecologically important predators in benthic and pelagic habitats. Although overexploitation and habitat degradation are the two biggest threats to batoid populations, coastal and oceanic pollution is also a pervasive potential threat. In this systematic review, we compile published scientific literature on trace metals and persistent organic pollutants (POPs) contamination in elasmobranch species of the Batoidea superorder and present contamination patterns, exposure effects, and potential human exposure risks to most reported contaminants. We found batoids to accumulate a wide range of trace metals, including mercury (Hg), arsenic (As), lead (Pb), copper (Cu), cadmium (Cd) and zinc (Zn). Accumulation of POPs is reported for chlordanes, dichlorodiphenyltrichloroethane (DDT), polychlorinated biphenyl (PCB), dieldrin, Heptachlor epoxide, hexachlorobenzene and perfluoroalkyl substances (PFAS). Hg levels in muscle tissue were significantly different among oceanic basins and habitats, consistent with previous global assessments of Hg oceanic background levels. Some batoid species presented Hg levels higher than large pelagic teleost fishes and comparable to sharks. Ecological traits such as, bottom feeding, upper trophic position and elasmobranch-specific physiology and metabolism are discussed as potential factors associated with Hg uptake and accumulation in batoids. Some species exceeded USEPA's maximum contamination safety limits in edible tissues for Hg, As and ΣPCBs. For most trace metals and POPs, there is a lack of studies focusing on contamination levels in batoids. We recommend future research increasing reporting on POPs and trace metals besides Hg in batoids to further investigate the role of Elasmobranch as a bioindicator for marine pollution.

A systematic grid sampling method and geostatistics were employed to investigate the spatial distribution, inventory, and potential ecological and human health risks of the residues of hexachlorobenzene (HCB) and chlorinated cyclodiene pesticides in soils of the Campanian Plain, Italy, and explore their relationship with the soils properties. The geometric mean (Gmean) concentrations of HCB and cyclodiene compounds followed the order CHLs (heptachlor, heptachlor epoxide, trans-chlordane, and cis-chlordane) > DRINs (aldrin, dieldrin, and endrin) > SULPHs (α-endosulfan, β-endosulfan, and endosulfan sulfate) > HCB. The residual levels of most cyclodienes in agricultural soils were generally higher than those of corresponding counterparts in the other land uses. Significant differences in the concentration of HCB and cyclodienes in the soils across the region are observed, and the Acerra-Marigliano conurbation (AMC) and Sarno River Basin (SRB) areas exhibit particularly high residual concentrations. Some legacy cyclodienes in the Campanian Plain may be attributed to a secondary distribution. The Gmean inventory of HCB, SULPHs, CHLs, and DRINs in the soil is estimated to be 0.081, 0.41, 0.36, and 0.41 metric tons, respectively. The non-cancer and cancer risks of HCB and cyclodienes for exposed populations are deemed essentially negligible, however, endosulfan poses significant ecological risks to some terrestrial species.

Under the German environmental specimen bank programme bream (Abramis brama) were sampled in six German rivers and analysed for the priority hazardous substances dicofol, hexabromocyclododecane (HBCDD), hexachlorobenzene (HCB), hexachlorobutadiene (HCBD), heptachlor + heptachlor epoxide (HC + HCE), polybrominated diphenylethers (PBDEs), polychlorinated dibenzo-p-dioxins and -furans and dioxin-like polychlorinated biphenyls (PCDD/Fs + dl-PCBs), and perfluorooctane sulfonic acid (PFOS). The aim was to assess compliance with the EU Water Framework Directive environmental quality standards for biota (EQSBiota) for the year 2013, and to analyse temporal trends for those substances that are of special concern. General compliance was observed for dicofol, HBCDD and HCBD whereas PBDEs exceeded the EQSBiota at all sites. For all other substances compliance in 2013 varied between locations. No assessment was possible for HC + HCE at some sites where the analytical sensitivity was not sufficient to cover the EQSBiota. Trend analysis showed decreasing linear trends for HCB and PFOS at most sampling sites between 1995 and 2014 indicating that the emission reduction measures are effective. Mostly decreasing trends or constant levels were also observed for PCDD/Fs and dl-PCBs. In contrast, increasing trends were detected for PBDEs and HBCDD which were especially pronounced at one Saar site located downstream of the industries and conurbation of Saarbrücken and Völklingen. This finding points to new sources of emissions which should be followed in the coming years.

The objective of this study was to evaluate the distribution pattern of persistent organic pollutants in water, sediment and aquatic biota represented by Oreochromis niloticus and Donax trunculus at the Rosetta Nile branch estuary. α-HCH, p,p′-DDE and polychlorinated biphenyls were the predominant compounds detected at ranges of 0.54–4.90 ng/l water, 0.75–2.41 ng/g, d. wt. sediment and 2.19–28.11 ng/g, fresh wt. biota. β and γ-HCHs, endosulfan compounds, heptachlor and heptachlor epoxide were at low detection frequencies. Totally, the organochlorine pollutants were at high levels and abundances in Donax spp. than in Tilapia spp. followed by sediment and water. These levels were ranged between lower and higher than those found by the other studies established in Egypt, and well below its tolerable residue levels in fish. A correlation was found for the quantified pollutants between water, sediment and biota. This is clearly reflecting the bioaccumulation properties of these compounds.

This study reports the concentrations of the priority pesticides (PPs) in 14 surface sediments and 21 layers of a sediment core from Óbidos Lagoon, a shallow Portuguese coastal lagoon. Results show that the PPs are confined to the upper part of the lagoon that receives most of the inputs from surface runoff of the surrounding agricultural fields and from small tributaries. Past and recent applied PPs were registered in sediments, aluminum normalized concentrations varying between 0.05×10−7 and 6.85×10−7. The PP risk assessment based on sediment quality guidelines like the “Probable Effect Level” (PEL) shows no biological effects in either sediments or aquatic organisms of Óbidos Lagoon, except for dieldrin, lindane, DDT, heptachlor epoxide and its parent compound heptachlor.

Organochlorine pesticides and PCB (POPs) concentrations were determined in the blood and eggs of green and hawksbill turtles. We compared concentrations between species, analyzed the relationship between turtle size and the POPs concentrations and the relationship between the concentrations in the blood of the nesting turtles and their eggs. We expected higher concentrations in the hawksbill turtle because of its higher trophic level, but concentrations were not higher in all the cases. Significant differences were found in δ-HCH blood concentrations. Lindane, heptachlor epoxide and PCB 101 concentrations were significantly higher in the hawksbill eggs. The relationship between the size of the turtles and the POP concentrations in the eggs of the hawksbills showed a negative correlation. No correlation was found between the size of the female and concentrations in the blood. In eggs, only the hawksbill turtles exhibited negative correlation in the concentration of mirex and PCB 44 and size.

Spatial gradients of polychlorinated biphenyls (PCBs) and organochlorine pesticides were examined in the young-of-the-year (YOY) bluefish (Pomatomus saltatrix) in the vicinity of a PCB Superfund Site in New Bedford Harbor, Massachusetts, and in the adjacent waters. PCB concentrations in bluefish varied between different locations, and also among fish from a given location. A generally decreasing gradient in PCB concentrations was evident as the bluefish were collected away from the Superfund Site. The average sum of PCB concentrations were highest for bluefish collected in the Upper Harbor between Interstate-195 Bridge and Coggeshall Street Bridge (Upper Harbor), followed by bluefish in Lower Harbor from north of Popes Island Bridge (Lower Harbor), and bluefish from Outer Harbor south of Hurricane Barrier (Outer Harbor). The levels of PCBs in bluefish from Clarks Cove and PCBs in bluefish from Buzzards Bay were similar and lowest among all bluefish specimens analyzed in the present study. Pesticide concentrations were about one order of magnitude or lower than the PCB concentrations, and the gradient of pesticide concentrations generally followed the gradient of PCB concentrations. Some of the commonly detected pesticides in the order of decreasing concentrations included DDTs and metabolites, heptachlor epoxide, endosulfan sulfate, and α-chlordane. Distribution of PCBs and organochlorine pesticides were examined in the tissues of YOY bluefish from Clarks Cove. PCBs and lipids in the brain samples of YOY bluefish were generally numerically greater than PCBs in the liver samples, but these differences were not statistically significant. PCBs and lipids in hypaxial muscle samples were numerically greater than PCBs in epaxial muscle samples, although these two groups of tissues were not statistically different. Despite the higher susceptibility of lighter PCB homologs to geophysical and biogeochemical weathering processes, the relative dominance of lighter homologs in the Upper Harbor and Lower Harbor samples suggested ongoing or recent sources of these lighter PCBs, particularly Aroclor 1242 and Aroclor 1016 in this area. The presence of heavier homologs in the Upper Harbor and Lower Harbor bluefish samples could be attributed to Aroclor 1252 and Aroclor 1254 that were being used in relatively smaller quantities in the manufacture of electrical components in addition to Aroclor 1242 and Aroclor 1016. The concentration of heavier PCB homologs appears to increase in YOY bluefish the further away from the PCB Superfund Site in the Acushnet Estuary the samples were collected. Principal component analyses of PCB 153 normalized concentrations of the individual PCB congeners resulted in two general groupings; a relatively tight group comprised of YOY bluefish from Upper Harbor, Lower Harbor, and Outer Harbor, and a rather loose and more dispersed group comprised of Buzzards Bay bluefish and the tissue samples of bluefish from Clarks Cove. Principal component analyses of major pesticides suggested close groupings of bluefish from Clarks Cove and bluefish from Buzzards Bay. Pesticides in bluefish from Upper Harbor, Lower Harbor, and Outer Harbor formed a loose group, with some bluefish from these locations populating close to Clarks Cove and Buzzards Bay bluefish. Although PCBs have been implicated in various behavioral and health effects in the experimental and field studies, the deleterious effects of chronic exposure to high concentrations of PCBs and the potential for recruitment of New Bedford Harbor YOY bluefish population to the adult stock remains obscure. Adaptive or evolutionary resistance to contaminants have been documented in resident species in some highly contaminated estuaries, however similar responses have not been investigated in the migratory species like bluefish. The results of the present study provide a reference baseline for YOY bluefish for “before-and-after” comparative studies and other toxicological studies for the New Bedford Harbor Superfund Site that is currently being remediated.