Background exposure to persistent organic pollutants predicts stroke in the elderly

Background exposure to persistent organic pollutants (POPs), lipophilic xenobiotics that accumulate mainly in adipose tissue, has recently emerged as a new risk factor for cardiovascular diseases. This prospective study was performed to evaluate if plasma concentrations of selected POPs predict incident stroke among the elderly. Twenty‐one POPs (including 16 polychlorinated biphenyl (PCB) congeners, 3 organochlorine (OC) pesticides, 1 brominated diphenyl ether (BDE), and 1 dioxin) were measured in plasma collected at baseline in 898 participants aged 70 years of the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS). Stroke diagnosis was validated by hospital records. During the five year follow-up, 35 subjects developed hospital-treated stroke. After adjusting for known stroke risk factors, most PCBs with 4, 5, or 6 chlorine atoms, p,p′-DDE, trans-nonachlor, and octachlorodibenzo-p-dioxin significantly predicted the risk of stroke. Across quartiles of summary measures of PCBs and OC pesticides, the adjusted ORs were 1.0, 0.8 (95% confidence interval: 0.2–2.5), 1.2 (0.4–3.4), and 2.1 (0.7–6.2) for PCBs and 1.0, 1.2 (0.3–4.2), 2.3 (0.7–6.9), and 3.0 (1.0–9.4) for OC pesticides (P for trend = 0.11 and 0.03, respectively). The adjusted ORs among participants ≥ 90th percentile of the summary measures were 5.5 (1.7–18.1) for PCBs and 4.0 (1.1–14.6) for OC pesticides; corresponding ORs for those ≥ 95th percentile were 7.8 (2.1–29.6) and 9.5 (2.3–38.9). Background exposure to POPs may play an important role in development or progression of stroke in the elderly.     

Contamination of persistent organic pollutants (POPs) and relevant management in China

The status of typical persistent organic pollutant (POP) contamination in many media (e.g., farm produce, soil, human milk, water, and sediments) was surveyed and China's relevant countermeasures for controlling POPs were analyzed in this paper. The results showed that the proportion of organochlorine pesticides (OCPs) to all kinds of pesticides has descended significantly since 1983 when the OCPs were forbidden from being used. The spatial distribution characteristic of pesticide application in the whole country was as follows: southeast>central>northwest. The pesticide residues in food with high fat and high protein content were more than that in foodstuffs. The residual concentration in soil in the whole country was as follows: south>central>north. Furthermore, in vegetable fields, the residual concentration was higher than that in crop fields. As for human milk, the retained amount tended to decrease. In the recent two decades, although the reduction was 81.5%, it was still higher than that in some developed European and American countries. The rank of the residual concentrations of OCPs in different media was: human milk>animal foodstuff>soil>vegetable food>water and sediment. The initial relevant POP management in China can be traced back to 1982 when the Ordinance of Pesticide Management was enacted. Now, environmental control of POPs in China is close to the international level. The legal management system of POPs can be divided into four facets, including 3 regulations, 6 ordinances, and 20 standards. However, on the whole, most of the existing regulations do not refer to POPs directly. Only some clauses mention POPs and lack pertinent, explicit statements on POP pollution and control. Legislation is urgently needed for more effective environmental management to enhance POP control.     

Screening ecological risk assessment of persistent organic pollutants in Mediterranean sea sediments

A screening ecological risk assessment (ERA) was conducted for the first time in the Mediterranean basin in order to assess the toxicity posed to the benthic community by PCBs, DDTs and HCB in marine sediments. The characterization of the exposure was conducted by means of an extensive literature survey, generating a database with more than 2000 samples. The effects were assessed by the adoption of guidelines previously developed in the literature, because ecotoxicological information about persistent organic pollutants (POPs) in the Mediterranean sediments was lacking. Existing sediment quality guidelines (SQGs) for the target pollutants were compiled and consensus values were calculated for three different categories of toxicity, namely threshold effect concentration (TEC), probable effect concentration (PEC) and extreme effect concentration (EEC). The combination of exposure and effects characterization enabled the identification of some areas of concern in the vicinity of industrial and urban locations and in the mouths of the main Mediterranean rivers. Beyond the Mediterranean continental shelf, the level of toxicity for the benthic community was generally low. The evaluation of the toxicity induced by the mixture of the target pollutants spotted the importance of DDT contamination in the Mediterranean sediments, despite the fact that main inputs to the sea have been significantly reduced during the last decades.     

Associations between blood persistent organic pollutants and 25-hydroxyvitamin D3 in pregnancy

Persistent organic pollutants (POPs) are suggested to contribute to lower vitamin D levels; however, studies in humans are scarce and have never focused on pregnancy, a susceptibility period for vitamin D deficiency. We investigated whether serum levels of POPs were associated with circulating 25-hydroxyvitamin D3 [25(OH)D3] concentration in pregnancy. Cross-sectional associations of serum concentrations of eight POPs with plasma 25(OH)D3 concentration were analyzed in 2031 pregnant women participating in the Spanish population-based cohort INfancia y Medio Ambiente (INMA) Project. Serum concentrations of POPs were measured by gas chromatography and plasma 25(OH)D3 concentration was measured by high-performance liquid chromatography in pregnancy (mean 13.3 ± 1.5 weeks of gestation). Multivariable regression models were performed to assess the relationship between blood concentrations of POPs and 25(OH)D3. An inverse linear relationship was found between serum concentration of PCB180 and circulating 25(OH)D3. Multivariate linear regression models showed higher PCB180 levels to be associated with lower 25(OH)D3 concentration: quartile Q4 vs. quartile Q1, coefficient = − 1.59, 95% CI − 3.27, 0.08, p trend = 0.060. A non-monotonic inverse relationship was found between the sum of predominant PCB congeners (PCB 180, 153 and 138) and 25(OH)D3 concentration: coefficient (95% CI) for quartile Q2 vs. Q1 [− 0.50 (− 1.94, 0.94)], quartile Q3 vs. Q1 [− 1.56 (− 3.11, − 0.02)] and quartile Q4 vs. Q1 [− 1.21 (− 2.80, 0.38)], p trend = 0.081. No significant associations were found between circulating 25(OH)D3 and serum levels of p,p′-DDE, p,p′-DDT, HCB, and ß-HCH. Our results suggest that the background exposure to PCBs may result in lower 25(OH)D3 concentration in pregnant women.     

Biomonitoring persistent organic pollutants in the atmosphere with mosses: Performance and application

Persistent organic pollutants (POPs) have aroused environmentalists and public concerns due to their toxicity, bioaccumulation and persistency in the environment. However, monitoring atmospheric POPs using conventional instrumental methods is difficult and expensive, and POP levels in air samples represent an instantaneous value at a sampling time. Biomonitoring methods can overcome this limitation, because biomonitors can accumulate POPs, serve as long-term integrators of POPs and provide reliable information to assess the impact of pollutants on the biota and various ecosystems. Recently, mosses are increasingly employed to monitor atmospheric POPs. Mosses have been applied to indicate POP pollution levels in the remote continent of Antarctica, trace distribution of POPs in the vicinity of pollution sources, describe the spatial patterns at the regional scale, and monitor the changes in the pollution intensity along time. In the future, many aspects need to be improved and strengthened: (i) the relationship between the concentrations of POPs in mosses and in the atmosphere (different size particulates and vapor phases); and (ii) the application of biomonitoring with mosses in human health studies.     

Body burden of metals and persistent organic pollutants among Inuit in the Canadian Arctic

Inuit living in the Arctic are exposed to elevated levels of environmental contaminants primarily due to long-range atmospheric transport. Blood sampling and contaminant biomonitoring was conducted as part of the International Polar Year Inuit Health Survey in 2007-2008. The body burden of metals (e.g. Cd, Pb) and persistent organic pollutants (e.g. PCBs, DDT & DDE, toxaphene, chlordane, PBDEs) were measured for Inuit participants (n = 2172) from 36 communities in Nunavut, Nunatsiavut, and the Inuvialuit Settlement Region, in Canada. The geometric mean of blood concentrations for Cd, Pb, PCBs, DDE & DDT, toxaphene, and chlordane were higher than those in the Canadian general population. A total of 9% of study participants exceeded the intervention guideline of 100 μg L^− 1 for Pb, 11% of participants exceeded the trigger guideline of 5 μg L^− 1 for Cd, and 1% exceeded the intervention guideline of 100 μg L^− 1 for PCBs. Also, 3% of women of child-bearing age exceeded blood Pb of 100 μg L^− 1 while 28% of women of child-bearing age exceeded 5 μg L^− 1 of PCBs. This work showed that most Inuit Health Survey participants were below blood contaminant guidelines set by Health Canada but that metal and POP body burdens commonly exceed exposures observed in the general population of Canada.     

Selective transfer of persistent organic pollutants and their metabolites in grey seals during lactation

Twenty grey seal (Halichoerus grypus) mother–pup pairs from the colony of the Isle of May (Scotland) were sampled at early and late lactation in order to study the transfer of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and their metabolites (HO-PCBs and HO-PBDEs) as well as organochlorine pesticides (OCPs), such as DDT and metabolites (DDXs) and hexachlorobenzene (HCB). The transfer of the naturally produced MeO-PBDEs was also investigated. Generally, concentrations (on a lipid weight basis) of the sum of PCBs, PBDEs and DDXs tended to be higher in all tissues at late lactation (for maternal outer blubber ΣPCBs = 3860 ± 2091 ng/g, ΣPBDEs = 120 ± 74 ng/g and ΣDDXs = 559 ± 207 ng/g; for maternal inner blubber ΣPCBs = 4229 ± 3274 ng/g, ΣPBDEs = 148 ± 118 ng/g and ΣDDXs = 704 ± 353 ng/g; for maternal serum ΣPCBs = 1271 ± 796 ng/g, ΣPBDEs = 27 ± 16 ng/g and ΣDDXs = 242 ± 125 ng/g; for milk ΣPCBs = 1190 ± 747 ng/g, ΣPBDEs = 55 ± 36 ng/g and ΣDDXs = 357 ± 160 ng/g; for pup serum ΣPCBs = 1451 ± 901 ng/g, ΣPBDEs = 48 ± 31 ng/g and ΣDDXs = 395 ± 201 ng/g). In all tissues, ΣMeO-PBDEs were found at very low levels or even undetected and their concentrations appeared to increase at late lactation only in maternal inner blubber (2.7 ± 1.3 to 5.3 ± 2.9 ng/g for early and late lactation, respectively) and milk (0.6 ± 0.3 to 1.1 ± 0.5 ng/g for early and late lactation, respectively). The transfer from inner blubber to maternal serum was selective and strongly depended on the log K_ow value of the compounds, with less lipophilic compounds being more efficiently released. Only a limited amount of HO-PCBs was transferred during lactation as 4-HO-CB-107 was the only metabolite detected in milk (29 to 40 pg/g lw). On the contrary, most of HO-PCB metabolites found in maternal serum were also detected in pup serum. These findings suggest not only a transplacental transfer of HO-PCBs from mothers to pups but also the possibility of endogenous biotransformation in suckling pups or accumulation of undetectable low amounts from milk.     

Human hair as a potential biomonitor for assessing persistent organic pollutants

To explore human biomonitor of persistent organic pollutants (POP) for public health risk assessment, extractable organohalogens (EOX), extractable persistent organohalogens (EPOX) and some selected organochlorine pesticides (OCP) and polychlorinated biphenyls (PCB) in children hair from urban and rural regions of Beijing, China, were measured by instrumental neutron activation analysis (INAA) and gas chromatography-electron capture detector (GC-ECD). The results indicated that about 96% of the total halogens existed as water-soluble polar compounds; about 25 to 50% of EOX were sulfuric acid-resistant EPOX; organochlorines were the major fraction of the organohalogens; and 88 to 99.6% of extractable persistent organochlorines (EPOCl) cannot be attributed to the selected OCP and PCB. HCH, DDT and 2-5CB were the major contributors to hair OCP and PCB. Further, gamma-HCH, p,p'-DDE, p,p'-DDT and PCB-52 were the predominant individuals of HCH, DDT and 2-5CB, respectively. The concentration distributions of EPOCl, HCH, DDT and PCB in children hair were generally in the order of urban>rural and girls>boys, except for PCB congeners with random distributions between genders. Pearson positive correlations between hair lipid and the detected parameters of hair gamma-HCH (p<0.01), DDT (p<0.01), EOCl (p<0.05), as well as EPOCl (p<0.05) were observed. Also, the ratios of hair alpha/gamma and p,p'-DDE/p,p'-DDT suggested that fresh input of HCH and DDT might exist in Beijing area. Hair can reflect body's integral exposure to POP from endogenous and exogenous sources, which, thus, can be used as a potential biomonitor in assessing POP exposure for public health purposes.     

Distribution of persistent organic pollutants in two different fat compartments from obese individuals

There are only few studies defining persistent organic pollutant (POP) concentrations in various fat compartments from living obese individuals. The present study has therefore determined the concentrations of various classes of organohalogenated compounds, such as dichlorodiphenyltrichloroethane and its metabolites (DDTs), chlordane compounds (CHLs), hexachlorocyclohexanes (HCHs), hexachlorobenzene (HCB), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecanes (HBCDs) in visceral fat (VF: n = 52) and subcutaneous abdominal fat (SF: n = 52) samples collected in 2010–2012 from obese individuals in Belgium. Organohalogen compounds were detected in all fat samples in the decreasing order of their concentrations: PCBs > DDTs > HCHs > CHLs > HCB > HBCDs > PBDEs, suggesting that Belgians have been widely exposed to these contaminants. The levels and the patterns of POP distribution in VF and SF tissue depots were not significantly different. Concentrations of PCBs (VF/SF; median: 285/275 ng/g lw) and DDTs (VF/SF; median: 150/155 ng/g lw) were the major POPs in all fat samples. Concerning PCBs, PCB 153 (VF/SF: 27/26%) was the most dominant congener, followed by PCB 180 (VF/SF: 17/18%), PCB 138 (VF/SF: 15/14.5%) and PCB 170 (VF/SF: 8.1/8.4%) to the sum PCBs, respectively. Levels of HBCDs (VF/SF; median: 4.0/3.7 ng/g lw) and PBDEs (VF/SF; median: 2.6/2.7 ng/g lw) were 1–2 orders of magnitude lower than those of PCBs and DDTs. Among PBDEs, BDE 153 (VF/SF: 31/34%) was the dominant congener, followed by BDE 47 (VF/SF: 26/23%), BDE 154 (VF/SF: 16/16%), BDE 100 (VF/SF: 10/11%) and BDE 99 (VF/SF: 9/9%). To our knowledge, this is the first report on HBCD concentrations in Belgian human fat tissues. Total PBDE and HBCD levels in human fat samples could not be correlated with age. In agreement with the literature, a significant correlation (p < 0.05) between age and the concentration of PCBs (r = 0.828), DDTs (r = 0.640), HCHs (r = 0.666), CHLs (r = 0.534) and HCB (r = 0.754), was observed in the present study. Levels of DDTs, HCHs, HCB and CHLs were also significantly correlated to each other, suggesting that they share similar exposure routes. Correlation with computed tomography (CT) scan data revealed that VF and VF/SF ratios are positive for most of the POPs, such as PCBs, PBDEs, p,p′DDE, CHLs, β-HCH, and HCB. To our knowledge, this study is the first to assess the relationship between POP levels in adipose tissue and markers of abdominal adiposity, determined by CT.     

Number of persistent organic pollutants detected at high concentrations in a general population

BackgroundSurveys of human exposure to environmental chemicals do not integrate the number of compounds detected per person and the concentration of each compound. This leaves untested relevant exposure scenarios, such as whether individuals with low concentrations of some compounds have high concentrations of the other compounds.ObjectiveTo analyze the number of persistent organic pollutants (POPs) detected at high concentrations.MethodsSerum concentrations of 19 POPs were analyzed by gas chromatography with electron-capture detection in a representative sample of the general population of Catalonia, Spain (N = 919).ResultsOver 58% of participants had concentrations in the top quartile of ≥ 1 of the eight most prevalent POPs, and 34% of ≥ 3 POPs. 83% of women 60 to 74 years old had concentrations of ≥ 3 POPs in the top quartile; 56% of women 60 to 74 years had p,p′-DDE, HCB and β-HCH all in their respective top quartiles, and 48% had concentrations of ≥ 6 POPs in the top quartile. Over 30% of subjects had concentrations in the top decile of 1 to 5 of the eight most prevalent POPs. Half of the population had levels of 1 to 5 POPs > 500 ng/g. Less than 4% had all eight POPs in the lowest quartile.ConclusionsMore than half of the study population had concentrations in the top quartile of ≥ 1 POPs. Significant subgroups of the population accumulate POP mixtures at high concentrations. POP concentrations appear low in most of the population only when each individual compound is looked at separately.     

Monitoring concentrations of persistent organic pollutants in the general population: the international experience

Assessing the adverse effects on human health of persistent organic pollutants (POPs) and the impact of policies aiming to reduce human exposure to POPs warrants monitoring body concentrations of POPs in representative samples of subjects. While numerous ad hoc studies are being conducted to understand POPs effects, only a few countries are conducting nationwide surveillance programs of human concentrations of POPs, and even less countries do so in representative samples of the general population. We tried to identify all studies worldwide that analyzed the distribution of concentrations of POPs in a representative sample of the general population, and we synthesized the studies' main characteristics, as design, population, and chemicals analyzed. The most comprehensive studies are the National Reports on Human Exposure to Environmental Chemicals (USA), the German Environmental Survey, and the Arctic Monitoring and Assessment Programme. Population-wide studies exist as well in New Zealand, Australia, Japan, Flanders (Belgium) and the Canary Islands (Spain). Most such studies are linked with health surveys, which is a highly-relevant additional strength. Only the German and Flemish studies analyzed POPs by educational level, while studies in the USA offer results by ethnic group. The full distribution of POPs concentrations is unknown in many countries. Knowledge gaps include also the interplay of age, gender, period and cohort effects on the prevalence of exposures observed by cross-sectional surveys. Local and global efforts to minimize POPs contamination, like the Stockholm convention, warrant nationwide monitoring of concentrations of POPs in representative samples of the general population. Results of this review show how such studies may be developed and used.     

Ecological and spatial factors drive intra- and interspecific variation in exposure of subarctic predatory bird nestlings to persistent organic pollutants

Top predators in northern ecosystems may suffer from exposure to persistent organic pollutants (POPs) as this exposure may synergistically interact with already elevated natural stress in these ecosystems. In the present study, we aimed at identifying biological (sex, body condition), ecological (dietary carbon source, trophic level) and spatial factors (local habitat, regional nest location) that may influence intra- and interspecific variation in exposure of subarctic predatory bird nestlings to polychlorinated biphenyl 153 (CB 153), polybrominated diphenyl ether 47 (BDE 47), dichlorodiphenyldichloroethylene (p,p′-DDE) and hexachlorobenzene (HCB). During three breeding seasons (2008–2010), we sampled body feathers from fully-grown nestlings of three ecologically distinct predatory bird species in subarctic Norway: Northern Goshawk (Accipiter gentilis), White-tailed Eagle (Haliaeetus albicilla) and Golden Eagle (Aquila chrysaetos). The present study analysed, for the first time, body feathers for both POPs and carbon (δ¹³C) and nitrogen (δ¹⁵N) stable isotopes, thus integrating the dietary carbon source, trophic level and POP exposure for the larger part of the nestling stage.Intraspecific variation in exposure was driven by a combination of ecological and spatial factors, often different for individual compounds. In addition, combinations for individual compounds differed among species. Trophic level and local habitat were the predominant predictors for CB 153, p,p′-DDE and BDE 47, indicating their biomagnification and decreasing levels according to coast > fjord > inland. Variation in exposure may also have been driven by inter-annual variation arisen from primary sources (e.g. p,p′-DDE) and/or possible revolatilisation from secondary sources (e.g. HCB). Interspecific differences in POP exposure were best explained by a combination of trophic level (biomagnification), dietary carbon source (food chain discrimination) and regional nest location (historical POP contamination).In conclusion, the combined analysis of POPs and stable isotopes in body feathers from fully-grown nestlings has identified ecological and spatial factors that may drive POP exposure over the larger part of the nestling stage. This methodological approach further promotes the promising use of nestling predatory bird body feathers as a non-destructive sampling strategy to integrate various toxicological and ecological proxies.     

An assessment of toxicity in profundal lake sediment due to deposition of heavy metals and persistent organic pollutants from the atmosphere

A Tier I Sediment Ecological Risk Assessment of profundal lake sediment contaminated by diffuse pollution of heavy metals and POPs deposited from the atmosphere was completed. The concentrations of seven heavy metals and four groups of POPs (OCs, PCBs, PAHs, PBDEs) were determined in the profundal sediment of ten lakes in the United Kingdom and two sediment toxicity tests completed (chironomid survival and emergence and cladoceran survival and reproduction). The results showed that around half the lakes are at least moderately contaminated by Pb, Zn, Cd, As and PAHs deposited from the atmosphere and the toxicity quotient suggests that the contaminants of concern are Pb, As and PAHs, and not the other metals nor OCs and PCBs. There was toxicity in the sediment of four of the lakes. The Probable Effect Concentration Quotient values indicated that metals in the sediments of Scoat Tarn, Agden Reservoir and Llyn Llagi were likely to be responsible for the laboratory toxicity found in these lakes, with PAHs also contributing in Agden Reservoir.     

Effects of persistent organic pollutants on the developing respiratory and immune systems: A systematic review

BackgroundDisruption of developing immune and respiratory systems by early-life exposure to persistent organic pollutants (POPs) could result into reduced capacity to fight infections and increased risk to develop allergic manifestations later in life.ObjectivesTo systematically review the epidemiologic literature on the adverse effects of early-life exposure to POPs on respiratory health, allergy and the immune system in infancy, childhood and adolescence.MethodsBased on published guidelines for systematic reviews, two independent researchers searched for published articles in MEDLINE and SCOPUS using defined keywords on POPs and respiratory health, immune function and allergy. Study eligibility criteria were defined to select the articles.ResultsThis review of 41 studies finds limited evidence for prenatal exposure to DDE, PCBs and dioxins and risk of respiratory infections. Evidence was limited also for postnatal exposure to PCBs, specifically ndl-PCBs, and reduced immune response after vaccination in childhood. The review indicates lack of association between postnatal exposure to PCBs/ndl-PCBs and risk of asthma-related symptoms. For the other exposure–outcome associations reviewed evidence was inadequate.Discussion and conclusionCurrent epidemiological evidence suggests that early-life exposure to POPs can adversely influence immune and respiratory systems development. Heterogeneity between studies in exposure and outcome assessment and the small number of studies for any given exposure–outcome relationship currently make comparisons difficult and meta-analyses impossible. Also, mechanisms remain largely unexplored. Recommendations for significantly improving our understanding thus include harmonization of exposure and outcome assessment between studies, conduct of larger studies, long-term assessment of respiratory infections and asthma symptoms in order to identify critical periods of susceptibility, integration of the potential immunotoxic mechanisms of POPs, and use of new statistical tools to detangle the role of multiple exposures on multiple outcomes.     

Distribution of polybrominated diphenyl ethers (PBDEs) and other persistent organic pollutants in human serum from Greece

Human serum samples (n=61) were collected in Attika, Greece between June and October 2007 and analyzed for polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCD), polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs). Thirty samples were collected from computer clerks of a large computer company in Athens working full-time with computers, and thirty-one from a control population in the Attika region with no computer use. Σ(5)PBDE concentrations (sum of tri- to hexa-BDEs) in all samples (n=61) ranged from 0.68 to 13.3 ng g(-1) lipid, with a median of 1.07 ng g(-1) lipid. These concentrations are on the lower end of those reported from other countries, probably reflecting lower usage of PBDE-containing products or lower exposures to these chemicals. Individual and Σ(5)PBDE concentrations did not statistically differ between the two groups of computer clerks and non-computer users (p>0.05), with the exception of BDE 153 (p=0.033). The predominant congener was BDE 153, followed by BDEs 47, 100, 99, 183, 154 and 28. HBCD was also detected in 70% of the samples. BDE 209 was detected in 8 out 61 samples (13%), with concentrations ranging from 1.18 to 19.1 ng g(-1) lipid, and a median of 2.94 ng g(-1) lipid. No age dependency was found for PBDEs. Σ(11)PCB (sum of PCBs 74, 99, 118, 138, 146, 153, 156, 170, 180, 183 and 187,) in all samples (n=61) ranged from 36 to 402 ng g(-1) lipid, with a median of 110 ng g(-1) lipid. pp'-DDE concentrations ranged from 53.8 to 1649 ng g(-1) lipid, with a median of 268 ng g(-1) lipid. This is the first study to report levels of PBDEs in a possibly occupationally exposed subset of the Greek population.     

Residues and source identification of persistent organic pollutants in farmland soils irrigated by effluents from biological treatment plants

Sewage and industrial effluents from biological treatment plant have been widely used for agricultural irrigation in north part of China. However, effluents after biological treatment still contain heavy metals and persistent organic contaminants. The persistent organic contaminants accumulated in soil may transfer through the food chains and cause adverse health effects on human or biological effects on soil fauna and flora after long-term application. In present study, field surveys were carried out in the farmlands irrigated by effluents from biological treatment plants that receive sewage wastewater and industrial discharges. Residues of polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides (OCPs) in the soils irrigated using both ground water and effluents were compared. The origins of PAHs in the soils were discussed. The results showed that wastewater irrigation could cause accumulation of PAHs in soils close to the pollution discharge. Significantly higher concentrations of PAHs were observed in the sampling sites close to the entrance of main channel in contrast to those along branches and the reference sites. There was no significant relationship between the accumulation of persistent organic pollutants and organic matter content in soil (TOC). Soil contamination of these persistent organic pollutants as affected by effluent irrigation was characterized by the dominant accumulation of high-molecular-weight PAHs (HMW-PAHs). In the case study, concentration of benzo[a]pyrane (BaP, 45.6 ng/g), indeno[1,2,3-cd]pyrene (IcP, 86.3 ng/g), benzo[g,h,i]perlene (BgP, 66.9 ng/g) could exceed the limits of the soil quality standard for biodegraded soils. In identification of the sources, the IcP/BgP values of PAHs in soils were more close to that in air particulates from coal/coke source (1.09+/-0.03 ng/g) [Dickhut RM, Canuel EA, Gustafson KE, Liu K, Arzayus KM, Walkers E, et al. Automotive sources of carcinogenic polycyclic aromatic hydrocarbons associated with particulate matter in the chesapeake bay region. Environ Sci Technol 2000;34:4635-40]. Therefore, both of the PAHs residues in effluents and emission from a nearby coal/coke plant were responsible. Also in this case study, low levels of the OCPs were observed and were not of significant concern in this wastewater irrigation area. Among the different OCPs analyzed, DDTs (mean 8.41 ng/g) and HCHs (mean 2.91 ng/g) were the major components. From the ratios of DDT/DDTs and beta-HCH/HCHs, it indicated that OCPs residues should be from historical usage.     

Global DNA hypermethylation is associated with high serum levels of persistent organic pollutants in an elderly population

Dioxin exposure has experimentally been associated with changes in DNA methylation, an epigenetic change that is associated with disease. The present study aims to investigate if serum levels of dioxin and other persistent environmental pollutants are related to global DNA methylation in a human sample. In the population-based Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study (all aged 70), global DNA methylation was measured by the Luminometric Methylation Assay in 524 subjects. Twenty-three different POPs, including 16 PCBs, five pesticides, one dioxin (OCDD) and one brominated flame retardant (BDE47) were analysed by HRGC/HRMS. Ten single nucleotide polymorphisms (SNPs) in the Aryl hydrocarbon (Ah)-receptor were analysed by mini-sequencing. High levels of toxic equivalency (TEQ) for PCBs and dioxin were associated with DNA hypermethylation (p = 0.030). This was mainly attributed to coplanar non-ortho PCBs. While no significant associations were found between DNA methylation and SNPs in the Ah-receptor, an interaction was found between the SNP rs2237297 and TEQ so that TEQ was associated with hypermethylation (p = 0.009) only in subjects with one G-allele (n = 103). Also high levels of the PCB126 congener, the OCDD, and the pesticide metabolite p,p′-DDE were related to DNA hypermethylation (p = 0.01, 0.03 and 0.003, respectively). In conclusion, in a sample of elderly subjects, high TEQ including PCBs and the dioxin OCDD and high serum levels of PCB126, OCDD, and p,p′-DDE were related to global DNA hypermethylation in a cross-sectional analysis.     

Association of persistent organic pollutants and non-persistent pesticides with diabetes and diabetes-related health outcomes in Asia: A systematic review

BackgroundOver half of the people with diabetes in the world live in Asia. Emerging scientific evidence suggests that diabetes is associated with environmental pollutants, exposures that are also abundant in Asia.ObjectiveTo systematically review the literature concerning the association of persistent organic pollutants (POPs) and non-persistent pesticides with diabetes and diabetes-related health outcomes in Asia.MethodsPubMed and Embase were searched to identify studies published up to November 2014. A secondary reference review of all extracted articles and the National Toxicology Program Workshop on the association of POPs with diabetes was also conducted. A total of 19 articles met the inclusion criteria and were evaluated in this review.ResultsTo date, the evidence relating POPs and non-persistent pesticides with diabetes in Asian populations is equivocal. Positive associations were reported between serum concentrations of polychlorinated dibenzodioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), and several organochlorine pesticides (DDT, DDE, oxychlordane, trans-nonachlor, hexachlorobenzene, hexachlorocyclohexane) with diabetes. PCDD/Fs were also associated with blood glucose and insulin resistance, but not beta-cell function. There were substantial limitations of the literature including: most studies were cross-sectional, few studies addressed selection bias and confounding, and most effect estimates had exceptionally wide confidence intervals. Few studies evaluated the effects of organophosphates.ConclusionsWell-conducted research is urgently needed on these pervasive exposures to inform policies to mitigate the diabetes epidemic in Asia.     

Analysis of the toxicogenomic effects of exposure to persistent organic pollutants (POPs) in Slovakian girls: correlations between gene expression and disease risk

The chemical composition of persistent organic pollutants (POPs) in the environment is not uniform throughout the world, and these contaminants contain many structurally different lipophilic compounds. In a well-defined study cohort in the Slovak Republic, the POP chemicals present in the peripheral blood of exposed children were chemically analyzed. The chemical analysis data revealed that the relative concentration and profile of structurally different organic pollutants, including polychlorinated biphenyls (PCBs), 2,2′-bis(4-chlorophenyl)-1,1-dichloroethylene (p,p′-DDE), 2,2′-bis(4-chlorophenyl)-1,1,1-trichloro-ethane (p,p′-DDT), hexachlorobenzene (HCB) and β-hexachlorocyclohexane (β-HCH), may vary from individual to individual, even within the same exposure area. These chemicals can be broadly classified into two groups. The first group, the PCB congeners, primarily originated from industrial compounds and their byproducts. The second group of compounds originated from or was commonly used in the agricultural sector (e.g., DDT, HCB). The objective of this study was to examine the effects of the two POP exposure profiles on gene expression. For the study population, we selected pre-pubertal girls (mean age of 46.2 ± 1.4 months) with high POP concentrations in their blood (> 75% tile of total POP) and classified them in the high ‘PCB’ group when the total PCB concentration was significantly higher than the total concentration of other POP components and in the ‘Other Than PCB’ (OTP) group, when the total PCB concentration was significantly lower than the concentration of the other major POP constituents. A matched control group of girls (< 25% tile of total POP) was selected for comparison purpose (n = 5 per group). Our aims were to determine whether there were any common effects of high POP exposure at a toxicogenomic level and to investigate how exposure may affect physiological functions of the children in two different exposure scenarios. Global gene expression analysis using a microarray (Affymetrix Gene Chip Human genome U133 Plus 2.0 Array) platform was conducted on the total RNA of peripheral blood mononuclear cells from the girls. The results were analyzed by Partek GS, Louis, MI, which identified twelve genes (ATAD2B, BIVM, CD96, CXorf39, CYTH1 ETNK1, FAM13A, HIRA, INO80B, ODG1, RAD23B, and TSGA14) and two unidentified probe sets, as regulated differentially in both the PCB and OTP groups against the control group. The qRT-PCR method was used to validate the microarray results. The Ingenuity Pathway Analysis (IPA) software package identified the possible molecular impairments and disease risks associated with each gene set. Connective tissue disorders, genetic disorders, skeletal muscular disorders and neurological diseases were associated with the 12 common genes. The data therefore identified the potential molecular effects of POP exposure on a genomic level. This report underscores the importance of further study to validate the results in a random population and to evaluate the use of the identified genes as biomarkers for POP exposure.     

A first evaluation of the usefulness of feathers of nestling predatory birds for non-destructive biomonitoring of persistent organic pollutants

In previous studies, feathers of adult predatory birds have been evaluated as valid non-destructive biomonitor matrices for persistent organic pollutants (POPs). In this study, we assessed for the first time the usefulness of nestling raptor feathers for non-destructive biomonitoring of POPs. For this purpose, we collected body feathers and blood of nestlings from three avian top predators from northern Norway: northern goshawks (Accipiter gentilis), white-tailed eagles (Haliaeetus albicilla) and golden eagles (Aquila chrysaetos). We were able to detect a broad spectrum of legacy POPs in the nestling feathers of all three species (Σ PCBs: 6.78-140ng g(-1); DDE: 3.15-145ng g(-1); Σ PBDEs: 0.538-7.56ng g(-1)). However, these concentrations were lower compared to other studies on raptor species, probably due to the aspect of monitoring of nestlings instead of adults. Besides their analytical suitability, nestling feathers also appear to be biologically informative: concentrations of most POPs in nestling feathers showed strong and significant correlations with blood plasma concentrations in all species (p<0.050; 0.775相似文献