Electronic waste (e-waste) disposal is a growing problem in China, and its effects on human health are a concern. To determine the concentrations of pollutants in peripheral blood and genetic aberrations near an e-waste disposal area in Jinghai, China, blood samples were collected from 30 (age: 41 +/- 11.01 years) and 28 (age: 33 +/- 2.14 years) individuals residing within 5 and 40 km of e-waste disposal facilities in Jinghai (China), respectively, during the week of October 21-28, 2011. Levels of inorganic pollutants (calcium, copper, iron, lead, magnesium, selenium, and zinc) and malondialdehyde (MDA), identities of persistent organic pollutants (POPs), micronucleus rates, and lymphocyte subsets were analyzed in individuals. Total RNA expression profiles were analyzed by group and gender. The population group living in proximity to the e-waste site displayed significantly higher mean levels of copper, zinc, lead, MDAs, POPs (B4-6DE, B7-9DE, total polychlorinated biphenyls, and BB-153). In addition, micronucleus rates of close-proximity group were higher compared with the remote group (18.27% vs. 7.32%). RNA expression of genes involved in metal ion binding and transport, oxidation/reduction, immune defense, and tumorigenesis varied between groups, with men most detrimentally affected (p<0.05). CD4(+) / CD8(+)T cell ratios, CD4(+)CD25(nt/hi)CD127(lo)regulatory T cell percentages, and CD95 expression were greater in the e-waste group (p < 0.05). Residing in close proximity to e-waste disposal facilities ( 5 km) may be associated with the accumulation of potentially harmful inorganic/organic compounds and gender-preferential genetic aberrations. (C) 2014 Elsevier Inc. All rights reserved.
A bibliometric analysis based on the Science Citation Index Expanded was conducted to provide insights into the publication performance and research trend of quantitative structure-activity relationship (QSAR) and quantitative structure-property relationship (QSPR) from 1993 to 2012. The results show that the number of articles per year quadrupled from 1993 to 2006 and plateaued since 2007. Journal of Chemical Information and Modeling was the most prolific journal. The internal methodological innovations in acquiring molecular descriptors and modeling stimulated the articles' increase in the research fields of drug design and synthesis, and chemoinformatics; while the external regulatory demands on model validation and reliability fueled the increase in environmental sciences. "Prediction endpoints", "statistical algorithms", and "molecular descriptors" were identified as three research hotspots. The articles from developed countries were larger in number and more influential in citation, whereas those from developing countries were higher in output growth rates.
Polybrominated diphenyl ethers (PBDEs) were measured in 87 soil samples collected from North China. Eleven PBDE congeners (BDE28, 47, 49, 66, 99, 100, 119, 183, 196, 203, and 209) were identified with a high frequency of detection (84-100 %) in soil samples, and their frequencies were used for statistical analysis in the present study. PBDE concentrations ranged from 0.08 to 8260 ng/g with a mean of 202 ng/g, thus indicating severe pollution at these sample sites. BDE209 was the predominant congener with concentrations of 0.08-8140 ng/g (mean 188). Analysis of the spatial distribution of PBDEs in North China soils indicated that relatively high concentrations of both lower- and higher-brominated BDEs were present in Shandong Province, and a decreasing trend in PBDE concentrations from the east toward the west of North China was observed. Source identification analysis suggested that Jinghai County in Tianjin and the coastal area of Laizhou Bay, Shandong province, were the major sources in North China. The sources in Jinghai County were connected with the dismantling of electronic waste, whereas the sources in the coastal area of Laizhou Bay were connected with the production of PBDEs. Modeling results showed that the distance between the sampling sites and these point sources had a large influence on the transfer of PBDEs.
Inhalation of pollutants is an important exposure route for causing human health hazards, and inhalation exposure assessment must take into account particle size distribution because particle-bound pollutants are size-dependent. Such information is scarce, particularly for residents dwelling within e-waste recycling zones where abundant atmospheric halogenated flame retardants (HFRs) commonly used in electronic/electrical devices have been widely reported. Atmospheric size-fractioned particle samples were collected using a 10-stage Micro-Orifice Uniform Deposit Impactor from an e-waste recycling zone in South China. The deposition efficiencies and fluxes of size-fractioned HFRs including polybrominated diphenyl ethers (PBDEs), alternative brominated flame retardants, and Dechlorane Plus in the human respiratory tract were estimated using the International Commission on Radiological Protection deposition model. The majority of HFRs was found to deposit in the head airways, with coarse particles (aerodynamic diameter (Dp) > 1.8 mu m) contributing the most (69-91%). Conversely, fine particles (Dp < 1.8 mu m) were dominant in the alveolar region (62-80%). The inhalation intake of PBDEs Within the e-waste recycling zone was 44 ng/d (95% confidence interval (CI): 30-65 ng/d), close to those through food consumption in non-e-waste recycling regions. The estimated total hazard quotient of particle-bound HFRs was 5.6 x 10(-4) (95% Cl: 3.8 x 10(-4)-8.8 x 10(-4)). In addition, incremental lifetime cancer risk induced by BDE-209 was 1.36 x 10(-10) (95% Cl: 7.3 x 10(-11)-2.3 x 10(-10)), much lower than the Safe Acceptable Range (1.0 x 10(-6)-1.0 x 10(-4)) established by the United States Environmental Protection Agency. These results indicate that the potential health risk from inhalation exposure to particle-bound HFRs for residents dwelling in the e-waste recycling zone was low.
Heterogeneous reactions between OH radicals and emerging flame retardant compounds coated on inert particles have been investigated. Organophosphate esters (OPEs) including triphenyl phosphate (TPhP), tris-2-ethylhexyl phosphate (TEHP), and tris-1,3-dichloro-2-propyl phosphate (TDCPP) were coated on (NH4)(2)SO4 particles and exposed to OH radicals in a photochemical flow tube at 298 K and (38.0 +/- 2.0) % RH. The degradation of these particle-bound OPEs was observed as a result of OH exposure, as measured using a Time-Of-Flight Aerosol Mass Spectrometer. The derived second-order rate constants for the heterogeneous loss of TPhP, TEHP, and TDCPP were (2.1 +/- 0.19) x 10(-12) (2.7 +/- 0.63) x 10(-12), and (9.2 +/- 0.92) x 10(-13) cm(3) molecule(-1) s(-1), respectively, from which approximate atmospheric lifetimes are estimated to be 5.6 (5.2-6.0), 4.3 (3.5-5.6), and 13 (11-14) days. Additional coating of the OPE coated particles with an OH radical active species further increased the lifetimes of these OPEs. These results represent the first reported estimates of heterogeneous reaction rate constants for these species. The results demonstrate that particle bound OPEs are highly persistent in the atmosphere with regard to OH radical oxidation, consistent with the assumption that OPEs can undergo medium or long-range transport, as previously proposed on the basis of field measurements. Finally, these results indicate that future risk assessment and transport modeling of emerging priority chemicals with semi- to low-volatility must consider particle phase heterogeneous loss. processes When evaluating environmental persistence.
A number of anti- and syn- isomers of heterocyclic hexacene diimides containing NH and O/S are synthesized. Two stable quinonoid diimides displaying low LUMO levels at less than -4.1 eV are obtained via oxidation of the anti- isomers. Reducing the isolated quinoidal molecules back to dihydro- forms offer pure anti- isomers.