Persistent Organic Pollutants Burden Research Articles

Soil's Hidden Power: The Stable Soil Organic Carbon Pool Controls the Burden of Persistent Organic Pollutants in Background Soils.

Persistent organic pollutants (POPs) tend to accumulate in cold regions by cold condensation and global distillation. Soil organic matter is the main storage compartment for POPs in terrestrial ecosystems due to deposition and repeated air-surface exchange processes. Here, physicochemical properties and environmental factors were investigated for their role in influencing POPs accumulation in soils of the Tibetan Plateau and Antarctic and Arctic regions. The results showed that the soil burden of most POPs was closely coupled to stable mineral-associated organic carbon (MAOC). Combining the proportion of MAOC and physicochemical properties can explain much of the soil distribution characteristics of the POPs. The background levels of POPs were estimated in conjunction with the global soil database. It led to the proposition that the stable soil carbon pools are key controlling factors affecting the ultimate global distribution of POPs, so that the dynamic cycling of soil carbon acts to counteract the cold-trapping effects. In the future, soil carbon pool composition should be fully considered in a multimedia environmental model of POPs, and the risk of secondary release of POPs in soils under conditions such as climate change can be further assessed with soil organic carbon models.

A meta-analysis highlighting the increasing relevance of the hair matrix in exposure assessment to organic pollutants

Owing to a wide range of advantages, such as stability, non-invasiveness, and ease of sampling, hair has been used progressively for comprehensive biomonitoring of organic pollutants for the last three decades. This has led to the development of new analytical and multi-class analysis methods for the assessment of a broad range of organic pollutants in various population groups, ranging from small-scale studies to advanced studies with a large number of participants based on different exposure settings. This meta-analysis summarizes the existing literature on the assessment of organic pollutants in hair in terms of residue levels, the correlation of hair residue levels with those of other biological matrices and socio-demographic factors, the reliability of hair versus other biomatrices for exposure assessment, the use of segmental hair analysis for chronic exposure evaluation and the effect of external contamination on hair residue levels. Significantly high concentrations of organic pollutants such as pesticides, flame retardants, polychlorinated biphenyls and polycyclic aromatic hydrocarbon were reported in human hair samples from different regions and under different exposure settings. Similarly, high concentrations of pesticides (from agricultural activities), flame retardants (E-waste dismantling activities), dioxins and furans were observed in various occupational settings. Moreover, significant correlations (p < 0.05) for hair and blood concentrations were observed in majority of studies featuring pesticides and flame retardants. While among sociodemographic factors, gender and age significantly affected the hair concentrations in females and children in general exposure settings, whereas adult workers in occupational settings. Furthermore, the assessment of the hair burden of persistent organic pollutants in domestic and wild animals showed high concentrations for pesticides such as HCHs and DDTs whereas the laboratory-based studies using animals demonstrated strong correlations between exposure dose, exposure duration, and measured organic pollutant levels, mainly for chlorpyrifos, diazinon, terbuthylazine, aldrin, dieldrin and pyrethroid metabolites. Considering the critical analysis of the results obtained from literature review, hair is regarded as a reliable matrix for organic pollutant assessment; however, some limitations, as discussed in this review, need to be overcome to reinforce the status of hair as a suitable matrix for exposure assessment.

Pacific salmon as vectors of environmental contaminants: An experimental test confirms synoptic surveys in natural streams

Pacific salmon transfer large quantities of material to tributaries during their spawning migrations, including carcass tissue and labile nutrients but also persistent organic pollutants (POPs) and heavy metals. We conducted a Before-After-Control-Intervention experiment by adding salmon carcasses and eggs to a Michigan (USA) stream that had never received inputs from non-native salmon to understand the bioaccumulation and persistence of biotransported contaminants. Our experimental outcomes were compared to previous studies using meta-analysis. Coincident with the introduction of salmon, the PCB and DDE burden of resident trout significantly increased. However, we did not observe changes in total mercury (Hg). Two years after the salmon addition experiment concluded, resident trout POP concentrations had returned to pre-addition levels, with no difference between the treatment and control reaches. Analysis of effect sizes suggested that the contaminant response observed in our experiment is consistent with field survey observations. Our study suggested that the consumption of salmon eggs drove the increase in POP burden of resident trout while Hg bioaccumulation was influenced by watershed sources. Critically, our study suggests that ecosystems are capable of quickly recovering from POP inputs from species migrations if contaminant sources are removed.

Prenatal exposure to persistent organic pollutants and changes in infant growth and childhood growth trajectories

BackgroundChildren are born with a burden of persistent organic pollutants (POPs) which may have endocrine disrupting properties and have been postulated to contribute to the rise in childhood obesity. The current evidence is equivocal, which may partly because many studies investigate the effects at one time point during childhood. We assessed associations between prenatal exposure to POPs and growth during infancy and childhood. MethodsWe used data from two Belgian cohorts with cord blood measurements of five organochlorines [(dichlorodiphenyldichloroethylene (p,p’-DDE), hexachlorobenzene (HCB), polychlorinated biphenyls (PCB-138, -150, −180)] (N = 1418) and two perfluoroalkyl substances [perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS)] (N = 346). We assessed infant growth, defined as body mass index (BMI) z-score change between birth and 2 years, and childhood growth, characterized as BMI trajectory from birth to 8 years. To evaluate associations between POP exposures and infant growth, we applied a multi-pollutant approach, using penalized elastic net regression with stability selection, controlling for covariates. To evaluate associations with childhood growth, we used single-pollutant linear mixed models with random effects for child individual, parametrized using a natural cubic spline formulation. ResultsPCB-153 was associated with increased and p,p’-DDE with decreased infant growth, although these results were imprecise. No clear association between any of the exposures and longer-term childhood growth trajectories was observed. We did not find evidence of effect modification by child sex. ConclusionOur results suggest that prenatal exposure to PCB-153 and p,p’-DDE may affect infant growth in the first two years, with no evidence of more persistent effects.

Infant Exposure to PCBs and PBDEs Revealed by Hair and Human Milk Analysis: Evaluation of Hair as an Alternative Biomatrix.

Human hair, as an emerging biological monitoring matrix, has begun to be used in various human exposure studies, but little research has been done on persistent organic pollutants (POPs), especially for the body burden of POPs in infants. In this study, 36 breast-fed infants in Shanghai were recruited for a study to determine their exposure to POPs, including 12 dioxin-like polychlorinated biphenyls (dl-PCBs), 6 indicator PCBs, and 8 polybrominated diphenyl ethers (PBDEs) in the inner layer (internal) and outer layer (external) of infant hair and human milk. The similarity or difference of the POP distribution pattern or concentration among these matrices was investigated, and only weak correlations (r < 0.4) were observed between the POP concentration in human milk and infant hair (internal or external). POPs in human milk have a different profile than those in infant hair, while they have stable concentration ratios (0.58-2.72), similar distribution patterns, fine Spearman's rank correlations, and tangled principal component analysis (PCA) plots in each POP family between external and internal hair samples. The result suggested that POPs in internal hair can be easily affected by those in external hair, but POPs in human milk seem to have little contribution to the POP profile in internal hair. Although infant hair cannot reflect the POPs from diet or from body burden, it can be an ideal biomatrix that estimates infant exposure to POPs from exogenous sources like house dust when considering the similar pattern of POPs and their proper accumulation period in hair.

Concentrations and geographical patterns of persistent organic pollutants (POPs) in meat from semi-domesticated reindeer (Rangifer tarandus tarandus L.) in Norway

The study aimed at investigating the concentrations and geographical patterns of 11 polychlorinated biphenyls (PCBs) and 15 organochlorine pesticides (OCPs) in reindeer muscle samples (n = 100) collected from 10 grazing districts in Norway, 2009. Concentrations were examined for patterns related to geographical region as well as age and sex of animals. Concentrations measured for PCBs and OCPs in reindeer meat samples were generally low. Geographical patterns were revealed and districts with previous mining activities, military trenches, or those that were in the vicinity of the Russian border exhibited slightly elevated concentrations compared to other districts. Calves (10 months) exhibited higher concentrations than young (1.5 year) and old animals (>2 years) adjusted for sex, whereas males exhibited higher concentrations than females, adjusted for age. All PCB congeners inter-correlated strongly with each other, whereas oxy-chlordane and heptachlor epoxide were the strongest inter-correlated OCP compounds. Concentrations of PCBs and OCPs in reindeer meat were all considerably lower than the maximum levels set for those contaminants in foodstuffs for safe human consumption by the European Commission. Thus, reindeer meat is not likely to be a substantial contributor to the human body burden of persistent organic pollutants.

Comparison of lipid-normalised concentrations of persistent organic pollutants (POPs) between serum and adipose tissue.

Human biomonitoring of persistent organic pollutants (POPs) is typically based on serum analysis and for comparison and modelling purposes, data are often normalised to the lipid content of the serum. Such approach assumes a steady state of the compound between the serum lipids and for example lipid-rich adipose tissue. Few published data are available to assess the validity of this assumption. The aim of this study was to measure concentrations of POPs in both serum and adipose tissue samples from 32 volunteers and compare the lipid-normalised concentrations between serum and adipose tissue. For p,p'-DDE, PCB-138, PCB-153 and PCB-180, lipid-normalised adipose tissue concentrations were positively correlated to the respective serum concentrations but generally were more highly concentrated in adipose tissue. These results suggest that the investigated legacy POPs that were consistently found in paired samples may often not be in a steady state between the lipid compartments of the human body. Consequently, the analysis of serum lipids as a surrogate for adipose tissue exposure may more often than not underestimate total body burden of POPs. Further research is warranted to confirm the findings of this study.

Determinants of Legacy Persistent Organic Pollutant Levels in the European Pond Turtle (Emys orbicularis) in the Camargue Wetland, France.

Many banned persistent organic pollutants (POPs) remain for decades in the aquatic environment and can have harmful effects on long-lived predators because of their high bioaccumulation and biomagnification potentials. We investigated the occurrence and levels of 18 polychlorinated biphenyls (PCBs) and 16 organochlorine pesticides in European pond turtles (n = 174) from April to July 2018 in the Camargue wetland, France. Although the Camargue was highly contaminated in previous decades, plasma occurrence and levels of POPs were very low: we were able to quantify only 3 of the 34 compounds we analyzed in >10% of the turtles. The burdens from POPs did not differ between males and females and were uncorrelated with sampling date and body mass. We observed differences in POP burdens between turtles from the 2 sampling sites. One possible explanation is that the sampling sites were in different agricultural hydraulic systems: plasma occurrence and levels were higher for PCB-52 and hexachlorobenzene in turtles captured in drainage channels and for PCB-153 at the site that receives irrigation. Finally, the occurrence and levels of PCB-153 in turtles increased with age, likely because of bioaccumulation and much higher exposure 20 to 30 yr ago than now. Environ Toxicol Chem 2021;40:2261-2268. © 2021 SETAC.

Persistent Organic Pollutants Burden, Trophic Magnification and Risk in a Pelagic Food Web from Coastal NW Mediterranean Sea.

The storage capacity, trophic magnification and risk of sixty-two POPs have been evaluated in a well-characterized pelagic food web (including phytoplankton, zooplankton, six fish, and two cephalopods species) from an impacted area in NW Mediterranean Sea. Our results show the high capacity of the planktonic compartment for the storage of polybrominated diphenyl ethers (PBDEs) and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), consistent with their estimated low trophic magnification factors (TMF) of 0.2-2.0 (PBDEs) and of 0.3-1.1 (PCDD/Fs). ∑PBDEs dominated in the zooplankton size-class 200-1000 μm (∼330 ng g-1 lw, median), whereas ∑PCDD/Fs accumulated preferentially in phytoplankton size-class 0.7-200 μm (875 pg g-1 lw, median). In contrast, polychlorinated biphenyls (PCBs) were preferentially bioaccumulated in the higher trophic levels (six fish species and two cephalopods) with TMFs = 0.8-3.9, reaching median concentrations of 4270 and 3140 ng g-1 lw (∑PCBs) in Atlantic bonito (Sarda sarda) and chub mackerel (Scomber colias), respectively. For these edible species, the estimated weekly intakes of dioxin-like POPs for humans based on national consumption standards overpassed the EU tolerable weekly intake. Moreover, the concentrations of nondioxin-like PCBs in S. sarda were above the EU maximum levels in foodstuffs, pointing to a risk. No risk evidence was found due to consumption of all other edible species studied, neither for PBDEs. The integrated burden of POPs in the food web reached ∼18 μg g-1 lw, representing a dynamic stock of toxic organic chemicals in the study area. We show that the characterized food web could be a useful and comprehensive "bioindicator" of the chemical pollution status of the study area, opening new perspectives for the monitoring of toxic chemicals in Mediterranean coastal waters.

Undernutrition combined with dietary mineral oil hastens depuration of stored dioxin and polychlorinated biphenyls in ewes. 2. Tissue distribution, mass balance and body burden.

Food safety crises involving persistent organic pollutants (POPs) lead to systematic slaughter of livestock to prevent contaminants from entering the food chain. Therefore, there is a need to develop strategies to depurate livestock moderately contaminated with POPs to reduce economic and social damage. This study aimed to test undernutrition (37% of energy requirements) combined with mineral oil (10% in total dry matter intake) in nine non-lactating ewes contaminated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and polychlorinated biphenyls (PCBs) 126 and 153 as a strategy to enhance the depuration of POPs through faecal excretion. To better understand the underlying mechanisms of the depuration process, lipophilic POPs and lipid fluxes were co-monitored in various body and excretion compartments. Body compartments (adipose tissues, muscle, liver and blood) and the total empty body were analyzed for lipids and POPs concentrations and burdens at slaughter, as well as excretion compartments (faeces and wool) collected during the depuration period. Decreases in empty body total and lipid weights were 6-fold higher in underfed and supplemented ewes compared to control ewes. In addition, over the depuration period undernutrition and supplementation treatment increased faecal TCDD, PCBs 126 and 153 excretions by 1.4- to 2.1-fold but tended to decrease wool PCB 153 excretion by 1.4-fold. This induced 2- to 3-fold higher decreases in the empty body POPs burdens for underfed and supplemented ewes. Nonetheless, when expressed relative to the calculated initial empty body burdens, burdens at slaughter decreased only slightly from 97%, 103% and 98% for control ewes to 92%, 97% and 94% for underfed and supplemented ones, for TCDD, PCBs 126 and 153, respectively. Fine descriptions at once of POPs kinetic (companion paper 1) and mass balance (companion paper 2), and of body lipid dynamics were very useful in improving our understanding of the fate of POPs in the ruminants.

Marine plastic debris in Central Chile: Characterization and abundance of macroplastics and burden of persistent organic pollutants (POPs)

In this study, we characterized plastic debris (PD) found on beaches from Concepción Bay in central Chile during spring 2017 and summer 2018. The identification of polymers was carried out using FT-IR. Persistent organic pollutants (POPs) were extracted with hexane using an ultrasonic bath and further quantified through GC–MS. The highest abundance of PD was obtained during the summer (4.1 ± 3.7 items/m2), with the most common size range between 2.5 and 10 cm (42%) and the most frequent shape were plastic fragments (44%). FT-IR analysis showed that polypropylene was the most recurrent plastic polymer found. The ∑10PBDEs ranged from 2.1 to 1300 ng/g in spring 2017 and 392 to 3177 ng/g in summer 2018. ∑7PCBs ranged from 0.9 to 93 ng/g during the spring 2017 and 0.3 to 4.5 ng/g for summer 2018. This study is the first with information on POPs occurrence in the plastic debris of central Chile.

Biological Traits and the Transfer of Persistent Organic Pollutants through River Food Webs.

Freshwater organisms remain at risk from bioaccumulation and biomagnification of persistent organic pollutants (POPs), but factors affecting their transfer through food webs are poorly understood. Here, we investigate transfer pathways of polychlorinated biphenyls, polybrominated diphenyl ethers, and organochlorine through a river food web, assessing the distribution and flux between basal resources (n = 3), macroinvertebrates (n = 22), and fish (n = 1). We investigate the effects of biological traits on the observed patterns and use trait-based models to predict POP bioaccumulation. Transfer pathways differed among POPs and traits such as habitat affinity, feeding behavior, and body size explained some variation in POP burdens between organisms. Trait-based models indicated that relationships between POPs, trophic transfers, and traits were relatively well conserved across a wider array of river food webs. Although providing more consistent predictions of POP bioaccumulation than steady-state models, variability in bioaccumulation across food webs limited the accuracy of trait-model predictions. As some of the first data to illustrate how ecological processes alter the flux of pollutants through river food webs, these results reveal important links between POPs and contrasting energetic pathways. These data also show the utility of trait-based methods in the assessment of persistent contaminants, but further field validations are required.

High intake of persistent organic pollutants generated by a municipal waste incinerator by breastfed infants

To monitor the body burden of persistent organic pollutants in mothers and infants living in proximity to a 10-year-old municipal waste incinerator (MWI), levels of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs) in the breast milk of mothers were evaluated, and the estimated daily intake (EDI) level of these pollutants in infants was assessed. In total, 14 mothers from the exposure area and 18 mothers from a control area were recruited for this study. In addition, the levels of 17 PCDD/F congeners and 18 PCB congeners in the breast milk of the mothers were estimated, and risk assessment for their infants by calculating their EDI levels was performed. The mean levels of ΣPCDD/Fs and TEQ-ΣPCDD/Fs in the breast milk of the exposure group were significantly greater than those of the control group (3.36 vs. 1.47 pg/g wet weight; and 0.24 vs. 0.12 pg TEQ/g wet weight, respectively; p < 0.05). With respect to PCBs, the mean levels of the total PCBs (ΣPCBs) and non-dioxin like-PCBs (ΣNDL-PCBs) in the exposure group were significantly greater than those in the control group (269 vs. 141 pg/g wet weight; 230 vs. 115 pg/g wet weight, respectively; p < 0.05). The mean levels of ΣPCDD/Fs and TEQ-ΣPCDD/Fs were positively correlated with the inhabit time of the exposure group (r = 0.636, r = 0.629, p < 0.05, respectively). The mean EDI level of the exposure group in infants was significantly greater than that of the control group (22.0 vs. 13.0 pg TEQ/kg bw day; p < 0.05). In conclusion, mothers and their breast-fed infants living in proximity to the 10-year-old MWI located in the Zhejiang Province of China exhibited a significantly higher body burden of PCDD/Fs and PCBs compared to those living in the control area.

Persistent Organic Pollutant-Mediated Insulin Resistance.

Persistent organic pollutants (POPs) such as organochlorine (OC) pesticides, polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs) have become wide-spread environmental contaminants as a consequence of their extensive use, long-range transport, and persistence. Because POPs are highly resistant to metabolic degradation, humans bioaccumulate these lipophilic and hydrophobic pollutants in fatty tissues for many years. Previous studies have demonstrated that POPs including PCBs are involved in the development of diabetes mellitus (DM) type 2 and insulin resistance. Numerous epidemiological studies suggest an association between POP burden and DM type 2/metabolic syndrome. In addition, several experimental studies have provided additional evidence supporting the association between POP exposure and DM type 2 or insulin resistance. Epidemiological and experimental studies have provided compelling evidence indicating that exposure to POPs increases the risk of developing insulin resistance and metabolic disorders. However, the detailed molecular mechanism underlying POP-induced insulin resistance is yet to be elucidated. In this article, we review literature that has reported on the association between POP burden and insulin resistance and the mechanism underlying POP-induced insulin resistance, and discuss implications for public health.

Persistent Organic Pollutant Burden, Experimental POP Exposure, and Tissue Properties Affect Metabolic Profiles of Blubber from Gray Seal Pups.

Persistent organic pollutants (POPs) are toxic, ubiquitous, resist breakdown, bioaccumulate in living tissue, and biomagnify in food webs. POPs can also alter energy balance in humans and wildlife. Marine mammals experience high POP concentrations, but consequences for their tissue metabolic characteristics are unknown. We used blubber explants from wild, gray seal ( Halichoerus grypus) pups to examine impacts of intrinsic tissue POP burden and acute experimental POP exposure on adipose metabolic characteristics. Glucose use, lactate production, and lipolytic rate differed between matched inner and outer blubber explants from the same individuals and between feeding and natural fasting. Glucose use decreased with blubber dioxin-like PCBs (DL-PCB) and increased with acute experimental POP exposure. Lactate production increased with DL-PCBs during feeding, but decreased with DL-PCBs during fasting. Lipolytic rate increased with blubber dichlorodiphenyltrichloroethane and its metabolites (DDX) in fasting animals, but declined with DDX when animals were feeding. Our data show that POP burdens are high enough in seal pups to alter adipose function early in life, when fat deposition and mobilization are vital. Such POP-induced alterations to adipose metabolic properties may significantly alter energy balance regulation in marine top predators, with the potential for long-term impacts on fitness and survival.

Air pollution and body burden of persistent organic pollutants at an electronic waste recycling area of China.

This paper reviews the concentrations of persistent organic pollutants (POPs) in atmosphere of an electronic waste (e-waste) recycling town, Guiyu, in Southeast China, focusing on polybrominated diphenyl ethers (PBDEs), polychlorinated dibenzo-p-dioxin and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs). We assess the evidence for the association between air pollution and human body burden, to provide an indication of the severity of respiratory exposure. Compared with standards and available existing data for other areas, it clearly shows that four typical POPs, derived from recycling processes, lead to serious atmospheric pollution and heavy body burden. From published data, the estimated respiratory exposure doses of Guiyu adults and children, varied between 2.48-10.37 and 3.25-13.6ngkg-1 body weight (bw) day-1 for PBDEs, 2.31-7.6 and 4.09-13.58pg World Health Organization-Toxic Equivalent Quantity (WHO-TEQ) kg-1bwday-1 for PCDD/Fs, 5.57 and 20.52ngkg-1bwday-1 for PCBs, and 8.59-50.01 and 31.64-184.14ngkg-1 bw day-1 for PAHs, respectively. These results show that air pollution is more harmful to children. Furthermore, except for PBDEs, the hazard quotient (HQ) of the other three pollutants was rated more than 1 by respiratory exposure only, and all of them are at risk of carcinogenesis. So we speculate these pollutants enter the body mainly through air inhalation, making respiratory exposure may be more important than dietary exposure in the Guiyu e-waste recycling area. Effective management policies and remediation techniques are urgently needed to prevent the deterioration of ambient air quality in the e-waste recycling area.

Maternal-Child Exposures to Persistent Organic Pollutants in Dhaka, Bangladesh

Information about the human burdens of persistent organic pollutants (POPs) in low- and middle-income countries is limited. In particular, studies often include only a small subset of POPs. To address this data gap, we aimed to assess maternal-child exposures to POPs in Dhaka, Bangladesh. We quantified 16 organochlorine pesticides, 12 polychlorinated biphenyls, 21 brominated flame retardants, 18 per- and polyfluorinated alkyl substances, 2 polycyclic aromatic hydrocarbons, and short-chain chlorinated paraffins in 18 pooled samples of human cord blood from 90 mother–infant pairs living in Dhaka, Bangladesh (2014–2015). In all pooled samples, we detected high levels of p,p′-DDT (median 81.6 ng/g lipid) and its metabolites p,p′-DDE and p,p′-DDD (median 551 and 10.7 ng/g lipid, respectively), where the p,p′-DDE/p,p′-DDT ratio ranged from 2.9 to 9.8 indicating recent dichlorodiphenyltrichloroethane (DDT) exposure. We also detected acenaphthene, decabromodiphenyl ethane, o,p′-DDT, o,p′-DDE, hexachlorobenzene, β-hexachlorocyclohexane, hexabromobenzene, and perfluorooctanoic acid in a subset of samples. For the other 59 target compounds, concentrations were below the limits of detection, despite using ultra-trace analytical methodology. No trends were observed when stratifying the analyses of detected POP concentrations by maternal age, maternal body mass index, or large fish consumption. These findings highlight recent DDT exposure in Dhaka, but the overall POP burden was otherwise low in this sample of pregnant women/newborns. Future monitoring efforts should focus on newly detected POPs for which burdens may be increasing due to ongoing industrialization in Bangladesh.

Longitudinal changes in persistent organic pollutants (POPs) from 2001 to 2009 in a sample of elderly Swedish men and women

BackgroundProspective cohort studies evaluating the temporal trends of background-level persistent organic pollutants (POPs) and their potential negative health effects in humans are needed. ObjectiveThe objectives of this study are to examine the five year longitudinal trend in chlorinated and brominated (Cl/Br) POP concentrations in a sample of elderly individuals and to investigate the relationship between gender, changes in body weight, plasma lipid levels and POP concentrations. MethodsIn the population-based Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study, plasma samples were collected from the same individuals over a 5 year period. Originally 992 subjects (all aged 70) were sampled between 2001 and 2004 and 814 returning subjects (all aged 75) were sampled again from 2006 to 2009. Plasma concentrations of 16 polychlorinated biphenyls (PCBs), 5 organochlorine pesticides (OCPs), octachlorinated dibenzo-p-dioxin (OCDD), and one polybrominated diphenylether (BDE 47) were determined using high-throughput 96-well plate solid phase extraction and gas chromatography-high resolution mass spectrometry (GC-HRMS). ResultsDuring the 5-year follow-up, plasma concentrations of all POPs significantly decreased (p < 0.00001). Median reductions ranged from 4% (PCB105) to 45% (PCB 99), with most reductions being in the 30–40% range. For most POPs, a larger decline was seen in men than in women. The relationship between the weight change and change in POP concentrations was generally negative, but a positive relationship between lipid levels and POP concentrations when expressed as wet-weight was observed. In general, similar changes in POP concentrations and their relationships to body weight were observed regardless of using either wet-weight (pg/mL) or lipid-normalized (ng/g lipid) concentrations. ConclusionIn this longitudinal cohort study, gender and minor, but varying changes in body weight and lipid levels greatly influenced the individual-based changes in POP concentrations. In general, our findings suggest that men and women with larger decreases in body weight and greater increases in lipid levels have the slowest decline in body burden of POPs. Based on the results from this study, either wet-weight or lipid normalized concentrations can be used to determine the percent change in POP concentrations and their relationships to physiological changes and differences.

Demographic, endocrine and behavioral responses to mirex in the South polar skua

Population consequences of chronic exposure to multiple pollutants at low environmental doses remain speculative, because of the lack of appropriate long-term monitoring surveys. This study integrates proximate and ultimate aspects of persistent organic pollutants (POP) burden in free-living vertebrates, by coupling hormonal and behavioral endpoints, life-history traits, and population dynamics. Blood samples (N=70) were collected in South polar skuas during two breeding periods, in 2003 and 2005, and individuals were annually monitored until 2011. Multi-state mark recapture models were used to test the effects of POP levels on demographic traits. Survival rate and long-term breeding probability were not related to individual POP levels, whereas long-term breeding success significantly decreased with increasing blood levels of mirex, an organochlorine insecticide. At the proximate level, corticosterone (stress hormone) and prolactin (parental care hormone) levels were not linked to individual POP burden. Nest defense in 2005 was significantly less intensive in chick-rearing skuas bearing higher mirex levels, suggesting reproductive behavioral impairment. Matrix population models were then built to project the rate of population decline according to increasing mirex burden. Although mirex levels were 2.8 times higher in 2003 than in 2005, the population-level effect of mirex was only detected in 2005, the year of higher corticosterone levels. The combination of endocrine traits with demographic analysis thereby enables to provide new support of synergistic interactions between pollutants and stress levels on long-term breeding outputs and population dynamics.

Legacy and new halogenated persistent organic pollutants in polar bears from a contamination hotspot in the Arctic, Hudson Bay Canada

A large and complex suite of 295 legacy and new halogenated persistent organic pollutants (POPs) were investigated in fat or liver tissue samples of polar bears collected in 2013–2014 from Southern (SHB) and Western (WHB) subpopulations of the Canadian Arctic contaminants hotspot of Hudson Bay. A total of 210 POPs were detected and/or quantifiable with some frequency in all fat or liver samples. POP profile and concentration differences were investigated both within (e.g. age and sex) and between the two subpopulations. Two time-point comparisons were made relative to POPs reported for Hudson Bay polar bears harvested in 2007–2008. ΣPolychlorinated biphenyl (PCB) concentrations at both time points were the most concentrated of the POP groups, and were spatially uniform with no detectable influence of sex or age, as were concentrations of the dominant congener CB153. ΣChlordanes (ΣCHLs, 74–79% oxychlordane) and the Σperfluoroalkyl substances (ΣPFASs, ≈60% perfluorooctane sulfonate (PFOS)) had the second greatest POP group concentrations in SHB and WHB respectively, with ΣPFASs and ΣCHLs being significantly influenced by age and/or sex. ΣCHLs were spatially uniform but ΣPFASs were greater in the SHB bears, as were e.g. some flame retardants, due to e.g. local contamination and/or changes in bear behavior and diet. Endosulfans and hexabromocyclododecane were detectable in samples from 2007–2008 but not from 2013–2014, which is consistent with their global POP regulations. ΣPolychlorinated naphthalenes (ΣPCNs) were consistently detected at relatively high concentrations compared to other arctic wildlife, however these concentrations were low relative to legacy POPs. ΣShort-chain chlorinated paraffins (ΣSCCPs) were major contributors to the overall POPs burden with concentrations comparable to other legacy POPs, though there was no significant difference between or within subpopulations for PCNs or SCCPs. Except for octachlorostyrene, POPs concentrations were generally lower in female and male bears from SHB in 2013–2014 relative to 2007–2008, however those of WHB males were greater over the same timeframe for almost all POPs.