Concentrations Of Organochlorine Compounds Research Articles

Back on top: Resuspended by dredging and other environmental disturbances, organochlorine compounds may affect the health of a dolphin population in a tropical estuary, Sepetiba Bay

Organochlorine compounds (OCs) are persistent organic pollutants linked to damaging the immune and endocrine systems, leading to a greater susceptibility to infectious diseases at high concentrations. Sepetiba Bay, in the Southeastern Brazilian coast, historically presents anthropogenic activities and environmental contamination that could negatively impact resident populations. In this context, this study aimed to investigate the temporal trends in the accumulation of organochlorine compounds over a 12-year database in the Guiana dolphins’ (Sotalia guianensis) resident population from Sepetiba Bay, including individuals collected before, during, and after an unusual mortality event triggered by morbillivirus (n = 85). The influence of biological parameters was also evaluated. The OCs concentrations in the blubber ranged from 0.98 to 739 μg/g of ΣPCB; 0.08–130 μg/g of ΣDDT; <0.002–4.56 μg/g of mirex; <0.002–1.84 μg/g of ΣHCH and <0.001–0.16 μg/g of HCB in lipid weight. Increased temporal trends were found for OCs in Guiana dolphins coinciding with periods of large events of dredging in the region. In this way, our findings suggest that the constant high OCs concentrations throughout the years in this Guiana dolphin population are a result of the constant environmental disturbance in the area, such as dredging. These elevated OCs levels, e.g., ΣPCB concentrations found above the known thresholds, may impair the response of the immune system during outbreak periods, which could lead the population to a progressive decline.

Soil properties and organochlorine compounds co-shape the microbial community structure: A case study of an obsolete site

Organochlorine compounds (OCs) such as chlorobenzenes (CB) are persistent organic pollutants that are ubiquitous in soils at organochlorine pesticides (OCP) production sites. Long-term contamination with OCs might alter the soil microbial structure and further affect soil functions. However, the effects of OCs regarding the shaping of microbial community structures in the soils of OCs-contaminated sites remain obscure, especially in the vertical soil profile where pollutants are highly concealed. Hence this paper explored the status and causes of OCs pollution (CB, hexachlorocyclohexane (HCH), and dichlorodiphenyltrichloroethane (DDT)) in an obsolete site, and its combined effects with soil properties (pH, available phosphorus (AP), dissolved organic carbon (DOC), etc) on microbial community structure. The mean total concentration of OCs in the subsoils was up to 996 times higher than that in the topsoils, with CB constituting over 90% of OCs in the subsoil. Historical causes, anthropogenic effects, soil texture, and the nature of OCs contributed to the differences in the spatial distribution of OCs. Redundancy analysis revealed that both the soil properties and OCs were important factors in shaping microbial composition and diversity. Variation partitioning analysis further indicated that soil properties had a greater impact on microbial community structure than OCs. Significant differences in microbial composition between topsoils and subsoils were observed through linear discriminant analysis effect size (LEfSe) analysis, primarily driven by different pollutant conditions. Additionally, co-occurrence network analysis indicated that heavily contaminated subsoils exhibited closer and more intricate bacterial community interactions compared to lightly contaminated topsoils. This work reveals the impact of environmental factors in co-shaping the structure of soil microbial communities. These findings advance our understanding of the intricate interplay among organochlorine pollutants, soil properties, and microbial communities, and provides valuable insights into devising effective management strategies in OCs-contaminated soils.

Levels and species-specific organochlorine accumulation in three shark species from the western Gulf of California with different life history traits

Organochlorine compounds (OCs), such as organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs), remain ubiquitous in marine ecosystems despite their prohibition or restriction, posing a risk to marine wildlife and humans. Their accumulation in liver tissue and potential toxicity in three exploited shark species (the scalloped hammerhead, Sphyrna lewini; the Pacific sharpnose shark, Rhizoprionodon longurio; and the Pacific angel shark, Squatina californica) with different physiological and ecological features from the western Gulf of California (GC) were investigated. Forty of the 47 OCs analyzed were identified, evidencing a greater agricultural than industrial influence considering the high DDTs/PCBs ratios. The DDT group was the main contributor to ∑OCs in the three species, while hexa- and hepta-CBs dominated the PCB profiles. S. lewini (juveniles) and R. longurio (juveniles and adults) had similar and significantly (p < 0.05) higher ∑OCP concentrations than S. californica (juveniles and adults), which is attributed to their migration to other polluted regions of the gulf. The three species' ∑PCB levels (lipid weight) were comparable and considered low in comparison to those documented in prior studies conducted worldwide. No intraspecific differences were observed when comparing by sex, but OC concentrations were higher in larger individuals. S. lewini and R. longurio showed different OC bioaccumulation trends against size, while no relationship between size and ∑OC concentrations was observed in S. californica. All shark species' toxic equivalents (TEQs) were calculated from dioxin-like PCB concentrations and were far below the established TEQ fish thresholds. However, future research is needed regarding the possible PCB and OCP effects in elasmobranchs. This study provides the basis for monitoring organic contaminants in predatory sharks from the western GC. It also highlights the importance of further research on unintentionally produced organochlorine environmental levels and sources.

Chromatographic Determination of the Concentration of Organochlorine Compounds in Crude Oil and Petroleum Products

Chromatographic Determination of the Concentration of Organochlorine Compounds in Crude Oil and Petroleum Products

Organochlorine contaminants in Rio skate (Rioraja agassizii), an endangered batoid species, from southeastern coast of Brazil

A global movement towards decreases in elasmobranch overfishing has been noted in the last decades. However, discussion concerning the effects of POP contamination on the health and survival of these organisms is still recent. These compounds can affect the immune and endocrine systems of both sharks and batoids, impairing reproduction and impacting species recruitment, acting synergistically alongside overfishing effects. In this context, this study investigated the concentration of organochlorine compounds in liver of 29 individuals of Rioraja agassizii, a commercially exploited skate classified as Vulnerable by IUCN and as Endangered in Brazil. Contaminant concentrations were higher in adults compared to juveniles. Distinct contamination profiles were observed, suggesting different groups within the investigated population and revealing contaminants as a potential tool to assess population ecology. PCB levels were considered a concern as they resemble concentrations in ecosystems from the northern hemisphere, where deleterious effects on elasmobranchs have been observed.

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

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

Study of the Rate of Corrosion of Steel 20 in the Presence of Increased Content of Organic Chlorinous Compounds in Oil

The paper presents data on the corrosion rate of steel 20 in the presence of organochlorine compounds in the oil. It is shown that with an increase in the concentration of organochlorine compounds, the corrosion rate of steel increases. It was found that with the addition of an inhibitor at CCl4 concentrations of 0.01 and 0.05%, the corrosion rate decreases, while at a CCl4 concentration of 0.03%, the corrosion rate does not change.

Improving the Quality of Cellulose for Use in Disposable Sanitary and Hygiene Products

Under modern conditions the creation of materials for sanitary hygiene and medical products based on cellulose is of paramount importance. Development and improvement in this area has become particularly relevant in the context of viral epidemics, including the COVID 19 pandemic. The production of disposable non-woven materials for sanitary and medical purposes has imposed a number of specific requirements on cellulosic raw materials used for their production including the content of impurities. The content of organochlorine compounds in the pulp is determined mainly by the bleaching technology. With the new bleaching technology, which includes ozonation and treatment with hydrogen peroxide, it is possible to minimize this content. An improved method for determination of the total chlorine and organically bound chlorine contents in cellulosic materials was developed on the basis of ISO 11480:2017. The method essentially involves the absorption of gaseous chlorine formed during the combustion process by an electrolyte and measurement of the amount of chloride ions by microcoulometric titration with determination of their mass in a recording device. The method is highly reliable and makes it possible to determine concentrations in the range of 1-1000 mg/kg.

Assessment of carcinogenic risk from exposure to chlororganic compounds of water of systems of centralized water supply

Introduction. The problem of providing the population with drinking water with guaranteed quality, safety, and physiological usefulness is highly relevant for many regions of Russia. The use of chlorination for disinfection of the water is a potential cause of the formation of excess concentrations of organochlorine compounds in it, including trihalogenomethanes, which leads to elevated levels of carcinogenic risk. The study’s object was: data on the content in water of centralized water supply systems of carcinogenic organochlorine compounds - chloroform, dichlorobromomethane and chlorodibromomethane. Material and methods. information on the incidence of the population of malignant neoplasms; the results of an experiment to evaluate the effectiveness of the preliminary ammonization method. The paper used methods of health risk assessment, variation statistics, and mathematical modeling. Results. The use of preliminary ammonization in Taganrog prevents the formation of trihalogenomethanes and ensures the maintenance of an individual multi-route carcinogenic risk at an acceptable level (9.933 · 10-6). Systematic unreasonable hyper chlorination of river water without prior ammoniation is the main reason for the excess content of chlororganic compounds and the high level of individual carcinogenic risk in the Primorsky rural settlement of the Neklinovsky District - up to 3.234 · 10-3 in 2015. Modeling on the basis of experimental chlorination of natural water indicates the high efficiency of preliminary ammonization in the disinfection mode, which ensures the content of free total active chlorine in tap water in the range from 0.8 to 1.2 mg/l. Conclusion. The high efficiency of the application of preliminary ammonization of natural water to prevent the formation of trihalogenomethanes and reduce carcinogenic risk has been confirmed. The priority factor for the formation of excess amounts of organochlorine compounds in drinking water is its hyper chlorination. Promising measures to reduce the carcinogenic risk of trihalogenomethanes in tap water include the systematic monitoring of their content, the use of preliminary ammonization, the exact dosage of chlorine, the deep purification of the source water before chlorination, the replacement of primary chlorination with ultraviolet disinfection, and others.

Организация контроля изменения содержания хлорорганических соединений на объектах подготовки нефти АО «Самаранефтегаз»

Организация контроля изменения содержания хлорорганических соединений на объектах подготовки нефти АО «Самаранефтегаз»

Influence of the seasonal and compositional changes on 4,4-dichlorodiphenyltrichloroethane (DDT) contamination in cows milk

The article presents the results of investigations on the determination of the content of organochlorine pesticides and DDT in the milk samples obtained in some settlements (village Movchanivka, Leninske, Mali Lisivtsi, Velikopolovetskye, and Pustovarivka), Skvirsky district, Kyiv oblast. The analysis of fat and protein content in milk in the winter and summer periods of the year. We registered that in the winter period with an increase of fat content in the milk, the concentration of DDT and its derivatives also increases. The content of organochlorine compounds in cow's milk did not exceed the maximum permissible level. In case of prolonged inflow of pesticide residues with food products into the human organism or feed into the animal organism, toxic substances gradually accumulate in them and have a negative influence on different functional systems of organisms, causing disturbances in their work. Purification from harmful substances is carried out by metabolic conversion of toxicants into more mobile in tissues compounds that can be more easily removed from the body. The process of removal of harmful substances, including metabolites of pesticides from the body warm-blooded with biological fluids and fecal masses is very long, and its intensity is mostly due to the degree of toxic load of xenobiotics on a person or animal. An indicator of the degree and quality of toxic exposure of humans and domestic animals to pesticides that live in a particular agricultural region may be the levels of these pesticides in human and warm-blooded milk. However, the most convenient and affordable indicator of pesticide exposure to organisms may be found in cattle milk, primarily cow milk. The great advantage of this object of toxic load indication is the unlimited possibility of biomaterial selection and deficiency of volumes, necessary for sanitary and hygienic researches because herds of cattle are almost in every farm of different agricultural regions.

The Relationship between Integrated Biochemical Index and Content of Organochlorine Xenobiotics in the Liver of the Black Scorpion Fish Scorpaena porcus Linnaeus, 1758, from Sevastopol Bays and Coastal Areas

Despite the ban on the use of organochlorine compounds (OCs), they are still widely distributed in various components of the Black Sea ecosystem, including fish. Sevastopol marine area, as a region of active economic use, is subject to significant anthropogenic impact. To assess the condition of the Black Sea scorpion fish Scorpaena porcus Linnaeus, 1758, from Sevastopol bays (Aleksandrovskaya, Streletskaya, Balaklavskaya, and Kazach’ia) and coastal areas (Laspi bay and Lyubimovka region), the liver of fish was analyzed to compare integrated biomarker response (IBR) and the concentrations of OCs: six indicator congeners of polychlorinated biphenyls (ΣPCB6) and organochlorine pesticides – р,p’-DDT and its metabolites p,p’-DDE and p,p’-DDD (ΣDDT). High concentrations of PCBs and DDTs were found in fish liver from Alexandrovskaya and Streletskaya bays, which are subject to significant anthropogenic impact: 2044 and 2019 ng/g wet weight for ΣPCB6 and 162 and 319 ng/g wet weight for ΣDDT, respectively. To determine the response of scorpion fish to the level of pollution, the liver of fish was analyzed to measure such biochemical markers as cholinesterase and catalase activities, albumin content, and the levels of oxidized proteins and lipid peroxidation. The set of these biochemical markers was used to calculate IBR. IBR correlated well with the ΣPCB6 concentration in sediments and liver of scorpion fish (r=0.95, p&lt;0.05). The maximum IBR was determined in the most polluted Alexandrovskaya and Streletskaya bays, where it was two orders of magnitude higher than the IBR in Laspi bay. Based on IBR values, the fish from Laspi and Kazach’ia bays and from the coastal area of Lyubimovka were in better condition than the fish from Alexandrovskaya, Streletskaya, and Balaklavskaya bays in summer seasons of 2016-2018

Trophic and fitness correlates of mercury and organochlorine compound residues in egg-laying Antarctic petrels

Understanding the drivers and effects of exposure to contaminants such as mercury (Hg) and organochlorine compounds (OCs) in Antarctic wildlife is still limited. Yet, Hg and OCs have known physiological and fitness effects in animals, with consequences on their populations. Here we measured total Hg (a proxy of methyl-Hg) in blood cells and feathers, and 12 OCs (seven polychlorinated biphenyls, PCBs, and five organochlorine pesticides, OCPs) in plasma of 30 breeding female Antarctic petrels Thalassoica antarctica from one of the largest colonies in Antarctica (Svarthamaren, Dronning Maud Land). This colony is declining and there is poor documentation on the potential role played by contaminants on individual physiology and fitness. Carbon (δ13C) and nitrogen (δ15N) stable isotope values measured in the females' blood cells and feathers served as proxies of their feeding ecology during the pre-laying (austral spring) and moulting (winter) periods, respectively. We document feather Hg concentrations (mean ± SD, 2.41 ± 0.83 μg g−1 dry weight, dw) for the first time in this species. Blood cell Hg concentrations (1.38 ± 0.43 μg g−1 dw) were almost twice as high as those reported in a recent study, and increased with pre-laying trophic position (blood cell δ15N). Moulting trophic ecology did not predict blood Hg concentrations. PCB concentrations were very low (Σ7PCBs, 0.35 ± 0.31 ng g−1 wet weight, ww). Among OCPs, HCB (1.02 ± 0.36 ng g−1 ww) and p, p’-DDE (1.02 ± 1.49 ng g−1 ww) residues were comparable to those of ecologically-similar polar seabirds, while Mirex residues (0.72 ± 0.35 ng g−1 ww) were higher. PCB and OCP concentrations showed no clear relationship with pre-laying or moulting feeding ecology, indicating that other factors overcome dietary drivers. OC residues were inversely related to body condition, suggesting stronger release of OCs into the circulation of egg-laying females upon depletion of their lipid reserves. Egg volume, hatching success, chick body condition and survival were not related to maternal Hg or OC concentrations. Legacy contaminant exposure does not seem to represent a threat for the breeding fraction of this population over the short term. Yet, exposure to contaminants, especially Mirex, and other concurring environmental stressors should be monitored over the long-term in this declining population.

Biotechnological processing of small-sized shrimps for using as seafood

Main technological and chemical characteristics of small-sized shrimps Pandalus borealis, P. goniurus and krill Euphausia superba are presented. The main processes of this kind of shrimp processing are described, with usage of its own complex of proteinases to produce autoproteolysis products. Lysates of these shrimps have high nutritional value comparable with the value of low-fat cottage cheese, though the shrimp lysate protein is a completely animal protein similar to beef one. As a source of low-fat protein, the shrimp lysates belong to the category of specialized and functional food and food ingredients; they also can de considered as the source of omega-3 fatty acids and astaxanthin. Volatile components of the shrimp lysates contain 30 compounds responsible for taste and aroma properties of crabs and shrimps, as thiran, methylthiran, dimethyldisulfide, thioacetic acid, 2-mercaptopropanoic acid, etc. Safety of shrimps and their lysates is provided by low content of organochlorine compounds, radionuclides, toxic elements and low values of microbiological parameters, below of the maximum permissible levels. The shrimp lysates are suitable for using in manufacture of emulsion and pasty products with high commodity properties, classified as gastronomic products with high taste and nutritional value.

Bioaccumulation of persistent organic pollutants in the gonads of Barbus barbus (Linnaeus, 1758).

Maps with grey or even white spaces are still present in spite of the fact that persistent organic pollutants (POPs) are at the forefront of research in aquatic toxicology and environmental safety. This is also the case for the Mureș River basin. The intensive use of industrial substances such as polychlorinated biphenyls (PCBs) and pesticides such as organochlorine compounds (OCPs) has caused global contamination of the aquatic environment. In our study we have found very high concentrations of both PCBs (2110-169,000ng/g lipid weight ΣPCB, 1950-166,000ng/g lipid weight ΣPCB7) and OCPs (1130-7830ng/g lipid weight ΣDDT, 47.6-2790ng/g lipid weight ΣHCH, 5.53-35.6ng/g lipid weight ΣChlordane, and 6.74-158ng/g lipid weight HCB) in the gonad tissue of Barbus barbus (Linnaeus, 1758) males and females. Contrary to most studies where the weight, length, and lipid percentage are positively correlated with the concentration of POPs from different tissue types, we observed a downward trend for the lipid normalized concentrations of some pollutants in gonads while these indices were actually increasing. The decrease of lipid normalized POPs with the increase of CF and lipid percentage may be due to the fact that individuals are eliminating hard and soft roes every year during reproduction which could mean that some quantities of pollutants are also eliminated along with the hard and soft roes. The high POPs concentrations found in our study should be a needed wakeup call for environmentalists and a starting point in developing monitoring and management measures for these pollutants.

Pine needle and semi-permeable membrane device derived organochlorine compounds (OCPs) concentrations in air in Mersin Province to Taurus, Turkey

Organochlorine pesticides (OCPs) were analyzed in three different ages (half-, 1.5-, 2.5-year-old) for needles and semi permeable membrane devices (SPMDs) at three deployment periods from sea level to 1881 meter above sea level. Individual HCHs concentrations ranged between 1.4 and 129 pg/g fw depending on the age and sampling season while 2.5-year-old needles showed higher HCHs levels compared to half and 1.5- year-old. Correlation between elevation and HCH concentration in SPMDs was found but not in needle samples. Concentrations of HCHs in SPMDs indicated clearly cold condensation effect on accumulation in winter period and increased with altitude. Concentrations of DDTs in half and 1.5-year-old needles were lower than 2.5-year-old needles. The highest total concentration of DDTs was detected in 1-year-period SPMD. Higher concentrations were found in 2.5-year-old needles for other OCPs. Seasonal and altitude-dependent changes were not observed for other OCPs in SMPDs. Total accumulation of OCPs in SPMDs were found higher than in needles. On the contrary, an increased accumulation rate was observed for HCHs in SPMD. In general, Total concentrations of DDTs and HCHs were similar to total of other OCPs in all altitudes when dominating endosulfan wasnot taken into account in the computation of total concentration of other OCPs.

Влияние хлорорганических соединений питьевой воды на здоровье населения

The authors carried out sanitary-hygienic assessment of the concentration of organochlorine compounds in drinking water distribution network and morbidity of the population. To analyze the current situation, monitoring data on the con- centrations of chlororganic compounds determined by gas-liquid chromatography and medico-demographic indicators of population health were used according to the official form of statistical reporting No. 12 (ICD 10). The results of 380 tests for the contents of three chlororganic compounds – chloroform, trichlorethylene and carbon tetrachloride – are presented in the article. Morbidity was represented by 10 classes of diseases: diseases of the digestive system, musculoskeletal system and connective tissue, genitourinary system, neoplasm, circulatory system diseases, endocrine system diseases, eating disorders and metabolic disorders, skin and subcutaneous tissue, nervous system, blood and blood-forming organs, respiratory system diseases. A method for assessing the risk of exposure to chemicals in environmental objects for public health is applied. It has been established that in case of chronic oral intake of chlororganic compounds with drinking water, unacceptable levels of non-carcinogenic risk are formed in respect to target organs such as the liver, kidneys, skin and nervous system in adults and children. Nevertheless, the individual carcinogenic risk for children and adults caused by the effects of high concentrations of chlororganic substances, the largest contribution to which belongs to trichlorethylene, today does not exceed the permissible level.

ДОСЛІДЖЕННЯ ЯКОСТІ ПИТНОЇ ВОДИ ЗА ПОКАЗНИКОМ ВМІСТУ ТРИГАЛОГЕНМЕТАНІВ

У статті досліджено якість питної води м. Запоріжжя за показником вмісту тригалогенметанів, а саме хлороформу (CHCI3), бромдихлорметану (CHBrCI2), дибромхлорметану (CHBr2CI) та трихлорметану (CHBr3). В основу досліджень покладено регламентований ДСанПін 2.2.4-171-10 хроматографічний метод визначення хлорорганічних сполук за ДСТУ ISO 10301-2004. Кількісне визначення тригалогенметанів проводилось на приладі хроматограф «Кристалл 2000М». Отримані результати щодо вмісту хлорорганічних сполук у воді не перевищують норми, що встановлені в Україні та ВООЗ.

Changes of organochlorine compound concentrations in maternal serum during pregnancy and comparison to serum cord blood composition

The concentrations of organochlorine compounds (OCs), including pentachlorobenzene, hexachlorobenzene (HCB), hexachlorocyclohexanes (α-, β-, γ- and δ-HCH), polychlorobiphenyls (PCBs 28, 52, 101, 118, 138, 153 and 180), DDT and metabolites, were measured in maternal serum samples collected at the first trimester of pregnancy, at delivery and in umbilical cord from a cohort of mother-newborn pairs from Tarragona (Spain) (n = 50), representing general population of a Mediterranean area from Southern Europe. The observed concentrations were generally low in comparison with previous studies in other world areas.Higher OC concentrations were observed in the maternal serum collected at delivery than in the first trimester and the cord blood concentrations were lower than the maternal levels. These results show for the first time a small but statistically significant increase in maternal venous concentration of OCs between the first trimester and delivery when measured in ng/ml.HCB, β-HCH and the PCB congeners in cord blood were significantly correlated with the concentrations of these compounds in maternal venous blood and the coefficients were stronger for the samples collected at delivery which was consistent with OC transfer from mother to foetus. In the case of DDT compounds, only 4,4′-DDT showed maternal-cord blood correlation which documented the low metabolic capacity of newborns for OC transformation, e.g. DDT into DDE.Maternal age was the most significant driver of the observed maternal venous OC concentrations in both periods, older ages involving higher concentrations. Higher body mass index was only significantly correlated with higher 4,4′-DDE concentrations in maternal venous blood and cord blood. In some cases, social class and education level were significantly correlated with OC concentrations, e.g. 4,4′-DDE in maternal venous blood from the first trimester and cord blood and PCB153 in maternal venous blood at delivery. In these cases, highest concentrations were found in the women with highest education level and most affluent social class.Comparison of the maternal OC concentrations of this cohort with those observed in 2002 in population of the same geographic area and age range shows decreases between two and ten times over this fourteen-year period.

High concentrations of persistent organic pollutants in adult killer whales (Orcinus orca) and a foetus stranded in Ireland

Bio-accumulation of persistent organic pollutants including polychlorinated biphenyls (PCBs), brominated flame retardants and organochlorine pesticides continue to be of major concern for marine apex predators such as killer whales. The concentrations of 16 polychlorinated biphenyls, 7 poly-brominated diphenyl ethers (PBDEs), 1 poly-brominated biphenyl (PBB) and a range of 19 organochlorine compounds (OCs) was investigated in blubber samples from a mother-foetus pair, an adult female and an adult male killer whale stranded in Ireland between 2010 and 2017. Concentrations ranged from 1.5 mg/kg to 49.3 mg/kg lipid weight and 0.04–1.2 mg/kg lipid weight for Σ16PCBs and Σ7PBDEs respectively. Concentrations of organochlorine compounds were also investigated in the male killer whale; a Σ19OC concentration of 49.4 mg/kg lipid weight was recorded. This study shows high levels of persistent organic pollutants occur in this species of whales stranded in Ireland.