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[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 Ptrend < 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 Ptrend < 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] 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] 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] 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 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] 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] Highlights: → Ultrasonic assisted miniaturized matrix solid-phase dispersion combined with HLLE was developed as a new method for the extraction of OCPs in fish. → The goal of this combination was to enhance the selectivity of HLLE procedure and to extend its application in biological samples. → This method proposed the advantages of good detection limits, lower consumption of reagents, and does not need any special instrumentation. - Abstract: In this study, ultrasonic assisted miniaturized matrix solid-phase dispersion (US-MMSPD) combined with homogeneous liquid-liquid extraction (HLLE) has been developed as a new method for the extraction of organochlorinated pesticides (OCPs) in fish prior to gas chromatography with electron capture detector (GC-ECD). In the proposed method, OCPs (heptachlor, aldrin, DDE, DDD, lindane and endrin) were first extracted from fish sample into acetonitrile by US-MMSPD procedure, and the extract was then used as consolute solvent in HLLE process. Optimal condition for US-MMSPD step was as follows: volume of acetonitrile, 1.5 mL; temperature of ultrasound, 40 deg. C; time of ultrasound, 10 min. For HLLE step, optimal results were obtained at the following conditions: volume of chloroform, 35 μL; volume of aqueous phase, 1.5 mL; volume of double distilled water, 0.5 mL; time of centrifuge, 10 min. Under the optimum conditions, the enrichment factors for the studied compounds were obtained in the range of 185-240, and the overall recoveries were ranged from 39.1% to 81.5%. The limits of detection were 0.4-1.2 ng g-1 and the relative standard deviations for 20 ng g-1 of the OCPs, varied from 3.2% to 8% (n = 4). Finally, the proposed method has been successfully applied to the analysis of the OCPs in real fish sample, and satisfactory results were obtained.
[en] Highly chlorinated pollutants are often found in river sediments, such as in the Yangtze River. In this study, the transformation of hexachlorobenzene, pentachlorophenol, polychlorinated biphenyl (PCB), hexachlorocyclohexane and perchloroethene was demonstrated in a mixed microbial culture enriched from Xiangxi River sediment [a tributary of Yangtze River belonging to the Three Gorges Reservoir (TGR)] which contained halo-respiring bacteria. Reductive dehalogenation by the Yangtze bacteria resulted in the formation of lower chlorinated metabolites, such as tri- and dichlorobenzenes, tri- and dichlorophenols, vinyl chloride and ethene. In case of PCB180, the lesser chlorinated metabolite PCB146 was detected and is recommended for future monitoring programs. Increased gene copy numbers of dechlorinating bacteria, e.g. Dehalococcoides spp. and Desulfitobacterium spp., were observed after the transformation of the chlorinated pollutants. In conclusion, the study demonstrates the capability of Yangtze River bacteria to dechlorinate several important chlorinated pollutants, indicating efficient pollutant turnover in the TGR area.
[en] In the process of designing and manufacturing an electronic system the digital oscilloscope plays an essential role but it also represents one of the most expensive equipment present on the typical workbench. In order to make electronic design more accessible to students and hobbyists, an affordable data acquisition system was imagined. The paper extensively presents the development and testing of a low cost, medium speed, data acquisition system which can be used in a wide range of electronic measurement and debugging applications, assuring also great portability due to the small physical dimensions. Each hardware functional block and is thoroughly described, highlighting the challenges that occurred as well as the solutions to overcome them. The entire system was successfully manufactured using high quality components to assure increased reliability, and high frequency PCB materials and techniques were preferred. The measured values determined based on test signals were compared to the ones obtained using a digital oscilloscope available on the market and differences less than 1% were observed. (paper)
[en] Sorbents amended to sediments in situ for sequestration of hydrophobic organic contaminants (HOCs) may be swept away from the treated sites due to hydrodynamic forces applied to the sediment surface. The purpose of this study is to examine the possibility of recovery of HOC availability in sorbent-amended sediment after complete removal of the sorbent. Sediment contact with an easily separable model sorbent Tenax beads for 28 days in a slurry phase resulted in 74–98% reduction in polycyclic aromatic hydrocarbon and polychlorinated biphenyl availability compared to the untreated controls. HOC availability in the sorbent-treated sediment slightly increased by sorbent removal and after one month of mixing in a slurry phase because the slowly-desorbing HOC fraction was released and repartitioned back to the sediment, partially replenishing the rapidly-desorbing HOC fraction. However, HOC availability did not further increase during an extended mixing period of 12 months suggesting that the repartitioning process was not an infinite source. HOC availability after the 12-month post-treatment mixing for the sorbent-treated sediment was 53–97% lower than that of the untreated sediment because of the combined effect of HOC mass removal from sediment (with the sorbent) and incomplete recovery of available HOC fraction in the sorbent-treated sediment. - Highlights: • Sorbent-sediment contact substantially reduces HOC availability in sediment. • HOC mass transfer to sorbent ranges 14–90% by 1-month slurry-phase contact. • Sorbent winnowing causes slight rebound of HOC availability in sediment. • HOC availability of treated sediment does not reach close to the initial value by sorbent winnowing. - HOC availability in sorbent-amended sediment is slightly increased but not fully recovered by removal of the sorbent and subsequent agitation of the remaining sediment.