[en] Polycyclic aromatic hydrocarbons (PAHs) are environmental pollutants. Exposure to PAHs is associated with several adverse health outcomes. However, no previous study has examined the relationship between PAH exposure and functional dependence in an elderly population. Our aim was to examine whether PAH exposure was associated with functional dependence including total disability, activities of daily living (ADL), instrumental activities of daily living (IADL), leisure and social activities (LSA), lower extremity mobility (LEM), and general physical activities (GPA) in an elderly population. A total of 5816 elderly adults from the National Health and Nutrition Examination Survey (NHANES) from 2001 to 2006 were examined. PAH exposure was measured by urinary biomarkers. Functional dependence was assessed by 19 structured questions. The association between PAH exposures with functional dependence was performed by using a multivariable linear regression model. After adjusting for pertinent variables, positive associations were observed between the total number of disabilities and 2-naphthalene and 1-pyrene quartiles (all P_trend < 0.05). There was a dose-dependent relationship between 1-pyrene quartiles and all functional dependence domains, and the higher quartile of 1-pyrene was more closely associated with functional impairment (all P_trend < 0.05). PAH exposure is associated with functional dependence in American elderly adults. Future research is needed to bring to light the pathophysiological underlying mechanisms related to these findings.

[en] Full text: Benzo[a]pyrene (B(a)P) has been identified by CRC CARE as a first tier priority contaminant (CRC CARE 2014) in Australia, and is classified by the US EPA as a priority pollutant due to its probable carcinogenicity. B(a)P is a common contaminant throughout Australia, ubiquitous in the urban, and to a lesser extent, regional environments. Although numerical screening levels for human health and the environment are available in Australia, these are stringent and often exceeded. The bioavailability of B(a)P varies considerably depending on the presence of other PAHs, the matrix, the age of contamination and so forth, and is difficult to measure. The application of the published investigation and screening levels is reasonably well understood, although to date it has generally not been possible to vary these levels to account for bioavailability even though it is suspected that B(a)P will not be bioavailable in many situations. In terms of management and remediation of B(a)P contamination, reasonably well understood methods of remediation are available such as physical-chemical treatment, thermal treatment, and landfill disposal. There are other potentially lower costs methods of treatment such as bioremediation that are often considered, but are less well understood. CRC CARE has undertaken a project to provide guidance on the risk-based management and remediation of B(a)P. This involved a working group comprising representatives of regulatory agencies, industry and research organisations. The objective of this project was to develop guidance that accounts for site-specific variables such as bioavailability, bioaccumulation and the exposure that will occur. It is intended that this guidance will assist practitioners, regulators and site owners to effectively manage and remediate B(a)P contaminated soil and groundwater, and will allow more targeted remediation and potentially reduce the cost of managing BaP contaminated soil and groundwater. In particular, the guidance is expected to be helpful in terms of providing higher reliability terrestrial ecological guideline levels that have been developed in accordance with the methodology in the NEPM for Ecological Screening Levels taking into account more recent information on toxicity tests that are now available; these guideline levels are considerably less stringent than those included in the NEPM 2013, which had taken a more precautionary position based on insufficient evidence. In addition, the guidance includes information on the options available for measurement of bioavailability and bioaccessibility, and provides recommendations about how conclusions can be reached regarding these parameters. This can be important when seeking to reach a conclusion as to level of risk likely to be posed by concentrations of B(a)P in soils that exceed the screening levels. The Guidance has been completed and has now been published as CRC CARE Publication No. 39 Risk-based management and remediation guidance for benzo(a)pyrene, January 2017. This presentation will outline the main findings of the work, the screening values that have been derived and their basis. (author)

[en] Highlights: • Mixed soil microbiomes could enhance the pyrene removal. • The nidA abundance in soil was positively related to the pyrene removal rate. • Microbial community may largely determine the function of pyrene removal. • Environmental factors and complex interactions affect the microbial community. Mixed soil microbiomes were established by introducing aliquots of a paddy soil into a red soil. The new mixed microbiomes effectively metabolized high-molecular-weight polycyclic aromatic hydrocarbons (PAHs, pyrene) in the soil mixtures. The pyrene removal efficiencies were 19% and 98%, respectively, in the original red soil and the paddy soil. The pyrene removal effectiveness by the mixed microbial community was enhanced by increasing the amount of paddy soil inoculant and the pyrene removal rates were 93%, 58% and 27% in paddy soil/red soil mixtures of 1:1, 3:7 and 1:9 (w/w), respectively. Supplementation with sterile paddy soil and nutrients changed the soil environment but the pyrene removal efficiency was not enhanced, indicating that the microbial composition largely determined the extent of pyrene removal. Moreover, the pyrene removal rate was positively related to the pyrene dioxygenase gene (nidA) abundance. The greater the percentage of the paddy soil in the soil mixture the greater the similarity of the mixed microbiome to that of the original paddy soil itself. The community of the inoculated sterile paddy soil was similar to that of the red soil and the community diverged from those of the red soil and the paddy soil with increasing culture time. After culture for 42 days, some enriched genera were responsible for PAH degradation, notably Nevskia, Ralstonia, Gemmatimonas and Lysobacter, while some genera have no clear classification information or category name at the genus level, such as f_Acidobacteriaceae and o_JG30-KF-AS9. This study is very important in recognizing the role of natural soil in the formation of a mixed microbiome to stimulate the degradation of PAHs in a soil with low intrinsic PAH degradation capability.

[en] Polycyclic aromatic hydrocarbons (PAHs) are a type of ubiquitous pollutant with the potential ability to cause endocrine disruption that would have an adverse health impact on the general population. To assess the maternal exposure to PAHs in neonates and evaluate the possible impact of PAHs on reproductive hormone levels, the concentration of PAHs and reproductive hormone levels in the umbilical cord serum of 98 mother-infant pairs in the Shengsi Islands were investigated. The median concentration of total PAHs was determined to be 164 (Inter-Quartile Range, IQR 93.6–267) ng g⁻¹ lipid, and 68% of the PAHs were lower-molecule congeners. The highest level was found for pyrene (PYR) and naphthalene (NAP), which contributed 54.6% of all the PAHs present in the samples. The exposure to PAHs negatively affected estradiol (E2) and Anti-Mullerian hormones (AMH) and positively affected FSH in the umbilical cord serum. The result expanded the database of the human burden of PAHs and suggested that PAHs can act as a type of Endocrine-Disrupting Chemical (EDC). These results may help to understand the complex pathways involved in disorders of human reproductive health associated with prenatal exposure to PAHs. - Highlights: • The concentration of PAHs and reproductive hormones in cord serum were evaluated. • Low-molecular-weight types constitute 68% of total PAHs body burden in cord serum. • Correlations between reproductive hormone levels and PAHs levels were studied. • Environmental exposure to PAHs affected E2 and AMH negatively and FSH positively. • Database of body burden of PAHs expanded, implied that the PAHs act as a EDCs. - In cord serum, low-molecular-weight types constitute 68% of total PAHs body burden and PAHs affected reproductive hormone both positively and negatively.

[en] A novel design of rapidly equilibrating passive air sampler was deployed at 38 sites across 19 European countries to investigate short-term spatial variability of persistent organic pollutants (POPs). Devices were sealed in airtight containers to eliminate the possibility of contamination during transit and couriered to recipients with deployment instructions. Exposure times of 7 days permitted the use of back trajectory analysis to further understand the factors responsible for influencing the large-scale spatial distribution of PCBs, PBDEs, PCNs, PAHs, lindane and HCB. Following sampler harvest, devices were sealed and returned for analysis. Comparison of sequestered levels showed that PAHs exhibited the greatest spatial variability (by a factor of 30) with higher levels often associated with greater population density. In contrast, HCB values were much more uniform, reflecting its well mixed distribution in the atmosphere. Spatial variation was strongly influenced by air mass origin, with lower levels being observed at most sites impacted by maritime air masses. - Polymer-coated glass (POG) slides are used as short-term air samplers in a survey of POPs in different European countries

[en] The lagoon system of Cote d'Ivoire (Ebrie, Bia, Lahou) with 1200 km² area, is the one of the most important in west Africa. The Ebrie lagoon is the main hydrology network of Abidjan and its suburbs. So it constitutes the receptacle of all kind of various origins effluents. Covering an area of 566 km², it stretches all along the Guinean Gulf between 3 deg. 40' and 4 deg. 50' West at the latitude of 5 deg. 20' North. In the context of national quality water assessment, a study of chemicals pollutants has been carried out on 11 stations along the lagoon system of Cote d'Ivoire. We were interested in organochlorine pesticides and PCB stored in oysters living in the lagoon bottoms. The samples taken in different stations have been extracted with hexane and purified on column of florisil deactivated at 5% at chemical treatment. Then the analysed is made by CPG/ECD. Our study shows the presence of compounds wastes such as the lindane, the heptachlor, the dieldrin, the endrin, the two metabolites of the DDT (PP'DDD and PP'DDE) and PCBs. The use of the ACP has permitted to highlight the highest stations of contamination that are those of Abidjan, the main industrial and urban zones (PCB:15-227 ng/g, DDT + DDD+DDE: 1.7-130ng/g). The use of variation of organochlorines compounds in oysters in time shows that contamination is reduced. Even if concentration still remain are important level. The contamination is representing acute and chronic poisoning for aquatic organisms and for humans

[en] The effect of CCl₄ in positronium (Ps) formation is examined in isooctane through positron lifetime spectroscopy experiments, in the framework of a series of studies on AOT-based reverse micellar systems. This solute appears as a rather strong Ps formation inhibitor, as expected in view of its well-known electron scavenging properties. The reciprocal of the triplet Ps intensity (1/Ι₃) varies linearly with CCl₄ concentration (C), up to about 0.08M, allowing to derive a high inhibition constant, k=36.6M^-1. Above 0.08M, however, the inhibition slackens out, which is attributed to an anti-inhibition effect. On the basis of previous reports on halocompounds, a general scheme of reactions is proposed to occur in the positron spur, including, besides the primary Ps formation through the e⁺/e^- reaction and the recombination reactions, electron scavenging by CCl₄ as the direct inhibiting reaction, followed by the reaction of the thus formed anion with the positron. The latter reaction may lead either to a [CCl₄Ps] bound-state or, if the positron picks off the electron from the anion, to some additional Ps formation. By using a simple quantitative approach to this scheme, an equation descriptive of the variation of Ι₃ with C is derived which agrees well with the experimental data. (author)

[en] Let G_m be a undirected graph. Having a Molecule, atoms indicate by vertices and bonds indicate by edges. The main aim of this paper explains Extended Medium Domination on Linear Benzenoid Chain like Benzene, Naphthalene, Anthracene and their generalisation will be proved. (paper)

[en] The occurrence and spatial distribution of polychlorinated naphthalenes (PCNs) were investigated in sediments, upland and paddy soils from the Liaohe River Basin. Concentrations of ΣPCNs were in the range of 0.33–12.49 ng g"−"1 dry weight (dw) in sediments and 0.61–6.60 ng g"−"1 dw in soils, respectively. Tri-CNs and tetra-CNs were the dominating homologues. An increasing trend of PCNs contamination was found in sediments with the rivers flowing through industrial areas and cities. Soils collected near cities exhibited higher abundance of PCNs than that of rural areas. The distribution of PCNs was related to the local industrial activities, rather than total organic carbon. Positive matrix factorization (PMF) was used for the source apportionment of PCNs in sediments and paddy soils. The result of PMF indicated that PCNs in sediments and paddy soils were mainly from the industrial processes, with additional contributions from the historical use of Halowax 1014 and atmospheric deposition. - Highlights: • Occurrence and distribution of PCNs were investigated in sediments and soils. • Tri-CNs and tetra-CNs were the dominating homologues. • Positive matrix factorization was used for the source apportionment of PCNs. • PCNs were mainly from the industrial processes. • Halowax 1014 and atmospheric deposition also contributed to PCNs pollution. - PCNs were less than 13.0 ng g"−"1 dw in sediments and soils from the Liaohe River Basin with the industrial processes as the major source.

[en] Sediment is an important sink for polycyclic aromatic hydrocarbons (PAHs) which are persistent organic contaminants. Phytoremediation has been reported as a cost-effective and convenient technique to clean up PAHs in freshly spiked sediments due to plant rootspromoted aerobic microbial degradation and sediment oxygenation. However, PAHs in aged sediments exhibit reduced bioavailability, and the effect of planting on bioavailability and biodegradation activity of PAHs in aged sediments has not been investigated. Therefore, in this study, Potamogeton crispus L. (P. crispus), a typical widespread submerged aquatic plant, was chosen as the model plant, and pyrene, a representative PAH, was selected as the target PAH. The objectives of this study were to compare the remedial effects of P. crispus on pyrene in aged sediments with those in unaged sediments and to further investigate the remedial mechanisms by developing kinetic models to quantitatively analyze the experimental results. (author)