Affiner votre recherche
Résultats 1-10 de 75
Human dietary exposure and levels of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), dioxin-like polychlorinated biphenyls (DL-PCBs) and non-dioxin-like polychlorinated biphenyls (NDL-PCBs) in free-range eggs close to a secondary aluminum smelter, Northern Italy
2015
Squadrone, S. | Brizio, P. | Nespoli, R. | Stella, C. | Abete, M.C.
PCDD/Fs and PCBs are environmentally persistent substances that have been associated with adverse effects on human health. Contamination of soils, animal feed and pastures leads to their bioaccumulation of in food products of animal origin, which are considered the major source of intake of these contaminants in humans. We analyzed eggs from free-range hens, sampled from small farms, located within a distance of 4.5 km from a secondary aluminum smelter in Northern Italy. The concentrations of PCDD/Fs, DL-PCBs and NDL-PCBs were higher in eggs from locations close to the plant, and strongly exceeded the limits set by EU Regulation 1259/2011 (2.5 pg WHO TEQ fat g−1 for PCDD/Fs, 5.0 pg WHO TEQ g−1 for PCDD/Fs and DL-PCBs L, 40 ng g−1 for NDL-PCBs). Consuming contaminated eggs may pose a risk for human health, especially for children (≤9 years) and infants (≤3 years), due to the 2-fold excess of the current exposure limits.
Afficher plus [+] Moins [-]Decadal re-evaluation of contaminant exposure and productivity of ospreys (Pandion haliaetus) nesting in Chesapeake Bay Regions of Concern
2015
Lazarus, Rebecca S. | Rattner, Barnett A. | McGowan, Peter C. | Hale, Robert C. | Schultz, Sandra L. | Karouna-Renier, Natalie K. | Ottinger, Mary Ann
The last large-scale ecotoxicological study of ospreys (Pandion haliaetus) in Chesapeake Bay was conducted in 2000–2001 and focused on U.S. EPA-designated Regions of Concern (ROCs; Baltimore Harbor/Patapsco, Anacostia/middle Potomac, and Elizabeth Rivers). In 2011–2012, ROCs were re-evaluated to determine spatial and temporal trends in productivity and contaminants. Concentrations of p,p′-DDE were low in eggs and below the threshold associated with eggshell thinning. Eggs from the Anacostia/middle Potomac Rivers had lower total PCB concentrations in 2011 than in 2000; however, concentrations remained unchanged in Baltimore Harbor. Polybrominated diphenyl ether flame retardants declined by 40%, and five alternative brominated flame retardants were detected at low levels. Osprey productivity was adequate to sustain local populations, and there was no relation between productivity and halogenated contaminants. Our findings document continued recovery of the osprey population, declining levels of many persistent halogenated compounds, and modest evidence of genetic damage in nestlings from industrialized regions.
Afficher plus [+] Moins [-]Effects of PAHs and dioxins on the earthworm Eisenia andrei: A multivariate approach for biomarker interpretation
2015
Sforzini, Susanna | Moore, Michael N. | Boeri, Marta | Bencivenga, Mauro | Viarengo, Aldo
In this study, a battery of biomarkers was utilised to evaluate the stress syndrome induced in the earthworm Eisenia andrei by exposure to environmentally realistic concentrations of benzo[a]pyrene (B[a]P) and 2,3,7,8-tetrachlorodibenzo-para-dioxin (TCDD) in OECD soil. The set of tests was then employed to assess the toxicity of field soils contaminated with organic xenobiotic compounds (such as PAHs, dioxins and PCBs). The results highlighted an impairment of immune and metabolic functions and genotoxic damage in worms exposed also to lower bioavailable concentrations of toxic chemicals. Multivariate analysis of biomarker data showed that all different contaminated soils had a detrimental effect on the earthworms. A separation between temporal and concentration factors was also evident for B[a]P and TCDD treatments; and field contaminated soils were further differentiated reflecting a diverse contamination. Multivariate analysis also demonstrated that lysosomal membrane stability can be considered a prognostic indicator for worm health status.
Afficher plus [+] Moins [-]Occurrence, bioaccumulation and risk assessment of dioxin-like PCBs along the Chenab river, Pakistan
2015
Eqani, Syed Ali Musstjab Akber Shah | Cincinelli, Alessandra | Mehmood, Adeel | Malik, Riffat Naseem | Zhang, Gan
This study aimed to assess the occurrence, distribution and dietary risks of seven dl-PCBs (dioxin-like PCBs) in eleven collected fish species from Chenab river, Pakistan. ∑7dl-PCBs (ng g−1, wet weight) burden was species-specific and the maximum average concentrations were found in Mastacembelus armatus (5.43), and Rita rita (5.1). Correlation of each dl-PCBs with δ15N%, indicated a food chain accumulation process of these chemicals into Chenab river, Pakistan. Species-specific toxicity of each dl-PCBs (WHO–PCBs TEQ) was calculated and higher values were found in three carnivore fish species i.e., M. armatus (2.5 pg TEQ g−1), R. rita (2.47 pg TEQ g−1), Securicola gora (2.98 pg TEQ g−1) and herbivore fish species i.e., Cirrhinus mrigala (2.44 pg TEQ g−1). The EDI (Estimated Daily Intake) values in most cases exceeded the WHO benchmark (4 pg WHO–TEQ kg−1 bw d−1) evidencing a potential health risk for consumers via fish consumption from Chenab river.
Afficher plus [+] Moins [-]Polychlorinated biphenyl exposure and corticosterone levels in seven polar seabird species
2015
Tartu, S. | Angelier, F. | Bustnes, J.O. | Moe B., | Hanssen, S.A. | Herzke, D. | Gabrielsen, G.W. | Verboven, N. | Verreault, J. | Labadie, P. | Budzinski, H. | Wingfield, J.C. | Chastel, O.
The role of polychlorinated biphenyls (PCBs) on exposure-related endocrine effects has been poorly investigated in wild birds. This is the case for stress hormones including corticosterone (CORT). Some studies have suggested that environmental exposure to PCBs and altered CORT secretion might be associated. Here we investigated the relationships between blood PCB concentrations and circulating CORT levels in seven free-ranging polar seabird species occupying different trophic positions, and hence covering a wide range of PCB exposure. Blood ∑7PCB concentrations (range: 61–115,632 ng/g lw) were positively associated to baseline or stress-induced CORT levels in three species and negatively associated to stress-induced CORT levels in one species. Global analysis suggests that in males, baseline CORT levels generally increase with increasing blood ∑7PCB concentrations, whereas stress-induced CORT levels decrease when reaching high blood ∑7PCB concentrations. This study suggests that the nature of the PCB-CORT relationships may depend on the level of PCB exposure.
Afficher plus [+] Moins [-]Contaminants of legacy and emerging concern in terrestrial passerines from a nature reserve in South China: Residue levels and inter-species differences in the accumulation
2015
Peng, Ying | Wu, Jiang-Ping | Tao, Lin | Mo, Ling | Tang, Bin | Zhang, Qiang | Luo, Xiao-Jun | Zou, Fa-Sheng | Mai, Bi-Xian
Knowledge is limited about the bioaccumulation of persistent halogenated compounds (PHCs) in terrestrial wildlife. Several PHCs, including dichlorodiphenyltrichloroethane (DDT) and its metabolites (designated as DDTs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), decabromodiphenylethane (DBDPE) and 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE), and stable isotopes (δ15N and δ13C) were analyzed in the muscle of four terrestrial passerines, Parus major, Copsychus saularis, Pycnonotus sinensis and Pycnonotus jocosus, from a nature reserve in South China. P. major had the highest PHC concentrations, with median values of 1060, 401, 92, 25 and 0.3 ng/g lipid weight for DDTs, PCBs, PBDEs, DBDPE and BTBPE, respectively. Fractions of DDT in P. jocosus and PCBs 153, 118 and 180 in C. saularis were higher compared with the other species. The inter-species differences in PHC concentrations and profiles could be attributed to the differences in trophic level, diet, living habits and metabolic capacity among the birds.
Afficher plus [+] Moins [-]Temporal and spatial trends in sediment contaminants associated with toxicity in California watersheds
2015
Siegler, Katie | Phillips, Bryn M. | Anderson, Brian S. | Voorhees, Jennifer P. | Tjeerdema, Ron S.
California's Stream Pollution Trends program (SPoT) assesses long-term water quality trends, using 100 base-of-the-watershed sampling sites. Annual statewide sediment surveys from 2008 to 2012 identified consistent levels of statewide toxicity (19%), using the freshwater amphipod Hyalella azteca. Significant contaminant trends included a decrease in PCBs, stable concentrations of metals and PAHs, and a statewide increase in detections and concentrations of pyrethroid pesticides. The pyrethroid pesticide bifenthrin was detected in 69% of samples (n = 410). Detection of toxicity increased in a subset of samples tested at a more environmentally relevant test temperature (15 °C), and the magnitude of toxicity was much greater, indicating pyrethroid pesticides as a probable cause. Pyrethroid toxicity thresholds (LC50) were exceeded in 83% of samples with high toxicity. Principal components analysis related pyrethroids, metals and total organic carbon to urban land use.
Afficher plus [+] Moins [-]Distribution of persistent organic pollutants (PAHs, Me-PAHs, PCBs) in dissolved, particulate and sedimentary phases in freshwater systems
2015
Rabodonirina, Suzanah | Net, Sopheak | Ouddane, Baghdad | Merhaby, Dima | Dumoulin, David | Popescu, Tudor | Ravelonandro, Pierre
The occurrence of three groups of hazardous organic contaminants (PCBs, PAHs, Me-PAHs) in fifteen watercourses and rivers located in highly urbanized and industrialized zones was studied. The distribution of 62 organic contaminants was determined in three matrices: in the dissolved phase, associated with suspended solid matter (SSM) and in sediment. Their distributions in the aquatic environment depend strongly on their physicochemical properties. Low molecular weight PAHs were predominant in the dissolved phase while those with high molecular weight accumulated preferentially in SSM and sediments. Among the 28 PCBs congeners, only PCB153 was detected. The results showed that the contamination of these areas originated mainly from combustion processes. The three the most polluted sites identified are surrounded by big cities. Ecotoxicological assessment based on the international Sediment Quality Guidelines (SQGs) showed that the toxic effects of the sediment in these watercourses and rivers occurred due to high levels of hydrocarbons.
Afficher plus [+] Moins [-]Temporal trends of mercury, organochlorines and PCBs in northern gannet (Morus bassanus) eggs from Bonaventure Island, Gulf of St. Lawrence, 1969–2009
2015
Champoux, Louise | Rail, Jean-François | Lavoie, Raphael A. | Hobson, Keith A.
Since 1969, northern gannet (Morus bassanus) eggs from Bonaventure Island, Québec, have been collected to monitor concentrations of contaminants. Levels of p,p′-DDE, which caused low breeding success of Bonaventure gannets in the 1960s, decreased by 99.4% from 1969 to 2009 (17.1–0.1 mg/kg ww), with concomitant improvement of hatching success. PCBs, most organochlorines and mercury also showed decreasing trends. Stable isotopes of carbon (δ13C) and nitrogen (δ15N) were measured to track the possible influence of diet changes on concentrations of contaminants over time. The confounding effect of the combustion of fossil fuels on baseline values of δ13C (the Suess effect) was taken into account. No temporal trends were observed in δ13C and δ15N values in gannet eggs. Hence trophic level or foraging area had a negligible influence on temporal trends of contaminants.
Afficher plus [+] Moins [-]Polychlorinated biphenyls and polybrominated biphenyl ethers in adipose tissue and matched serum from an E-waste recycling area (Wenling, China)
2015
Lv, Quan-Xia | Wang, Wenyue | Li, Xing-Hong | Yu, Lianlian | Zhang, Yun | Tian, Yuan
To Date, the knowledge on relationship between PCBs/PBDEs exposure and thyroid hormones (THs) levels during pregnancy still needs to be extended. Meanwhile, studies on congener-specific adipose-serum ratios for PCBs/PBDEs were limited. This study reports the levels of PCBs/PBDEs in serum-adipose tissue samples (n = 64) from expectant women living surrounding e-waste recycling sites in Wenling, China. Their concentrations varied from several to hundreds of ng g−1 lipid. Maternal exposure to PCBs was associated with lower TSH during pregnancy, suggesting possible implication for maternal health and fetal development. The compound levels between the adipose tissue and matched serum samples were highly correlated (p < 0.001), generating a predicted adipose-serum partitioning relationship for individual PCB congener and PBDE congener. Molecular characteristics, such as Kow value, molecular weight and molecular volume, may play a key role in the variable partitioning of some compounds between serum and adipose tissue.
Afficher plus [+] Moins [-]