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Shi S.,National Research Center for Environmental Analysis and Measurement | Huang Y.,National Research Center for Environmental Analysis and Measurement | Dong L.,National Research Center for Environmental Analysis and Measurement
Bulletin of Environmental Contamination and Toxicology | Year: 2013

Year-round air samples were collected at Beijing on a weekly basis from 2009 to 2010, to determine the levels, gas-particle distribution, seasonal variations and compositional profiles of 8 polybrominated diphenyl ether congeners. The annual mean atmospheric concentrations of Σ 7PBDEs and BDE-209 were 6.16 pg/m3(N.D-23.6 pg/m 3) and 164 pg/m3 (30.7-454 pg/m3), respectively. The results showed wide consumption of industrial products containing commercial deca-BDE mixtures in Beijing. The seasonal variations showed that lower brominated congeners had higher levels and greater proportions in the gaseous phase at warm sampling periods than the higher brominated counterparts. © 2012 Springer Science+Business Media New York.


Qi L.,University of California at Riverside | Qi L.,National Research Center for Environmental Analysis and Measurement | Nakao S.,University of California at Riverside | Nakao S.,Colorado State University | Cocker III D.R.,University of California at Riverside
Journal of the Air and Waste Management Association | Year: 2012

This work investigates the oxidative aging of preformed secondary organic aerosol (SOA) derived from α-pinene ozonolysis (~100 ppbv hydrocarbon [HCx] with excess of O3) within the University of California-Riverside Center for Environmental Research and Technology environmental chamber that occurs after introduction of additional hydroxyl (OH) and nitrate (NO3) radicals. Simultaneous measurements of SOA volume concentration, hygroscopicity, particle density, and elemental chemical composition (C:O:H) reveal increased particle wall-loss-corrected SOA formation (1.5%, 7.5%, and 15.1%), increase in oxygen-to-carbon ratio (O/C; 15.6%, 8.7%, and 8.7%), and hydrophilicity (4.2%, 7.4%, and 1.4%) after addition of NO (ultraviolet [UV] on), H2O2 (UV on), and N2O5 (dark), respectively. The processing observed as an increase in O/C and hydrophilicity is attributed to OH and NO3 reactions with first-generation vapor products and UV photolysis. The rate of increase in O/C appears to be only sufficient to achieve semivolatile oxygenated organic aerosol (SV-OOA) on a day time scale even at the raised chamber radical concentrations. The additional processing with UV irradiation without addition of NO, H2O2, or N2O5 is observed, adding 5.5% wall-loss-corrected volume. The photolysis-only processing is attributed to additional OH generated from photolysis of the nitrous acid (HONO) offgasing from chamber walls. This finding indicates that OH and NO3 radicals can further alter the chemical composition of SOA from α-pinene ozonolysis, which is proved to consist of first-generation products.Secondary organic aerosol (SOA) may undergo aging processes once formed in the atmosphere, thereby altering the physicochemical and toxic properties of aerosol. This study discusses SOA aging of a major biogenic volatile organic compound (VOC; α-pinene) after it initially forms SOA. Aging of the α-pinene ozonolysis system by OH (through NO or H2O2 injection), NO3 (through N2O5 injection), and photolysis is observed. Although the reaction rate appears to be only sufficient to achieve semivolatile oxygenated organic aerosol (SV-OOA) level of oxygenation on a 1-day scale, it is important that SOA aging be considered in ambient air quality models. Aging in this study is attributed to further oxidation of gas-phase oxidation products of α-pinene ozonolysis.Supplemental Materials: Supplemental materials are available for this paper. Go to the publisher's online edition of the Journal of the Air & Waste Management Association for information on the referenced α-pinene ozonolysis reaction and chamber reactor temperature. © 2012 Copyright 2012 A&WMA.


Liu G.,CAS Research Center for Eco Environmental Sciences | Zheng M.,CAS Research Center for Eco Environmental Sciences | Du B.,CAS Research Center for Eco Environmental Sciences | Du B.,National Research Center for Environmental Analysis and Measurement | And 5 more authors.
Chemosphere | Year: 2012

Iron ore sintering processes constitute significant sources of dioxins, and studies have confirmed a close correlation between polychlorinated naphthalenes (PCNs) and dioxin formation. Thus, iron ore sintering processes are thought to be a potential source of PCNs, although intensive investigations on PCN emissions from sintering processes have not been carried out. Therefore, the aim of the present study was to qualify and quantify PCN emissions from nine sintering plants operating on different industrial scales. PCN concentrations ranged from 3 to 983ngm-3 (0.4-23.3pgTEQPCNm-3) and emission factors ranged from 14 to 1749μgt-1 (0.5-41.5ngTEQPCNt-1), with a geometric mean of 84μgt-1 (2.1ngTEQPCNt-1). The estimated annual emission of PCNs from sintering processes in China was 1390mg TEQPCN. These figures will assist in the development of a PCN emissions inventory. Regarding emission characteristics, PCNs mainly comprised low-chlorinated homologs. The ratios of several characteristic PCN congeners were also measured and compared with those from other sources. Taken together, these results may provide useful information for identifying the sources of PCNs produced by iron ore sintering processes. © 2012 Elsevier Ltd.


Zhang L.,National Research Center for Environmental Analysis and Measurement | Shi S.,National Research Center for Environmental Analysis and Measurement | Dong L.,National Research Center for Environmental Analysis and Measurement | Zhang T.,National Research Center for Environmental Analysis and Measurement | And 2 more authors.
Chemosphere | Year: 2011

In this study, polychlorinated biphenyls (PCBs) pollution in the surface water of the Yangtze River Delta (YRD) was investigated. A total of 26 samples were collected from water bodies in three cities within the YRD during the dry season from October to November of 2009. The total PCBs (dissolved plus particulate) ranged from 1.23 to 16.6ngL -1 and were dominated by tri-, tetra-, and penta-chlorinated biphenyls. The mean PCBs in the Beijing-Hangzhou Grand Canal and the Yangtze River were 8.84 and 3.36ngL -1, respectively. A t-test showed that there were no significant differences in the concentration of samples from the metropolitan area and the development zone. According to the Chinese national environmental quality standards for surface water (GB 3838-2002), the concentrations of PCBs observed in this study do not pose a hazard to aquatic or human health. Overall, this study described the PCB concentration and homolog distribution patterns in one of the most rapidly developing areas in China, and the results can be used as reference levels for future PCB monitoring programs. © 2011 Elsevier Ltd.


Guan W.,China Agricultural University | Xu P.,National Research Center for Environmental Analysis and Measurement | Wang K.,China Agricultural University | Song Y.,China Agricultural University | Zhang H.,China Agricultural University
Food and Chemical Toxicology | Year: 2011

A simple, quick and reliable analytical method for the determination of 1-naphthylacetic acid in garlic and soil has been developed in this study. The residual levels and dissipation rates of 1-naphthylacetic acid in garlic and soil were determined by high performance liquid chromatography-tandem mass spectroscopy (HPLC-MS/MS). The limit of quantification (LOQ) of the developed method was 0.005. mg/kg. The half-lives of 1-naphthylacetic acid in garlic plants and soil were 0.80-1.4. days and 0.94-2.0. days, respectively. The final residues of 1-naphthylacetic acid in garlic, garlic sprout and soil could not be detected and were all below 0.05. mg/kg (the MRL of EU). Results of the ultimate residues in garlic and soil showed that this pesticide is safe to be used under the recommended dosages. © 2011 Elsevier Ltd.


Zhang L.,National Research Center for Environmental Analysis and Measurement | Zhang T.,National Research Center for Environmental Analysis and Measurement | Dong L.,National Research Center for Environmental Analysis and Measurement | Shi S.,National Research Center for Environmental Analysis and Measurement | And 2 more authors.
Science of the Total Environment | Year: 2013

The objective of this study was to quantify organic chlorinated pesticides, polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and polycyclic aromatic hydrocarbons (PAHs) in air samples collected from July 2009 to April 2010 in Suzhou, Wuxi and Nantong in the Yangtze River Delta (YRD) and to identify potential sources of these pollutants during the period. Gas- and particle-phase concentrations of these species were determined using gas chromatography-mass spectrometry on samples collected using high volume samplers. Phenanthrene, fluoranthene, hexachlorobenzene (HCB), p,p'-DDE, tri-CB (#18), tri-CB (#28) and deca-BDE (#209) were the most abundant compounds in the YRD. Average concentrations of these pollutants in Suzhou, Wuxi and Nantong, respectively, were 88.4, 105 and 69.5ng/m3 for PAHs, 162, 237 and 136pg/m3 for HCB, 35.7, 41.7 and 34.7pg/m3 for hexachlorocyclohexane, 131, 83.1 and 229pg/m3 for DDTs, 63.4, 52.4 and 31.7pg/m3 for chlordanes, 80.5, 51.8 and 65.1pg/m3 for PCBs, 30.4, 32.0 and 54.6pg/m3 for PBDEs (tri- to hepta-BDE) and 882, 807 and 1200pg/m3 for deca-BDE (#209). Concentrations of the emerging persistent organic pollutant, deca-BDE (#209), in the three cities were greater than those of other countries. Massive production and/or the use of commercialized deca-BDE (#209) may occur in metropolitan areas and development zones in the YRD. © 2013 Elsevier B.V.


Zhang L.,National Research Center for Environmental Analysis and Measurement | Yang W.,National Research Center for Environmental Analysis and Measurement | Zhang L.,Capital Normal University | Li X.,Capital Normal University
Chemosphere | Year: 2015

The formation of unintentionally produced persistent organic pollutants (POPs) may occur during various chlorination processes. In this study, emissions of unintentionally produced POPs during the methanol-based production of chlorinated methanes were investigated. High concentrations of highly chlorinated compounds such as decachlorobiphenyl, octachloronaphthalene, octachlorostyrene, hexachlorobutadiene, hexachlorocyclopentadiene, hexachlorobenzene, and pentachlorobenzene were found in the carbon tetrachloride byproduct of the methanol-based production of chlorinated methanes. The total emission amounts of hexachlorocyclopentadiene, hexachlorobutadiene, polychlorinated benzenes, polychlorinated naphthalenes, octachlorostyrene, and polychlorinated biphenyls released during the production of chlorinated methanes in China in 2010 were estimated to be 10080, 7350, 5210, 427, 212, and 167kg, respectively. Moreover, polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) were formed unintentionally during chlorinated methanes production, the emission factor for PCDDs/DFs was 364μg toxic equivalency quotient (TEQ) t-1 product for residues, which should be added into the UNEP toolkit for updating. It was worth noting that a high overall toxic equivalency quotient from polychlorinated naphthalenes and PCDDs/DFs was generated from the chlorinated methanes production in China in 2010. The values reached 563 and 32.8g TEQ, respectively. The results of the study indicate that more research and improved management systems are needed to ensure that the methanol-based production of chlorinated methanes can be achieved safely. © 2015 Elsevier Ltd.


PubMed | National Research Center for Environmental Analysis and Measurement and Beijing University of Chemical Technology
Type: | Journal: Chemosphere | Year: 2017

In this study, from July 2011 to June 2012, 31 sampling sites were identified in order to investigate the concentrations and sources of polycyclic aromatic hydrocarbons (PAHs), as well as to evaluate their potential health risks in the cities of Suzhou, Wuxi, and Nantong, which are located in the Yangtze River Delta (YRD). The samples were collected by means of passive air sampling (PAS), and the contents of 15 PAHs were detected by gas chromatography-mass spectrometry. The


PubMed | University of Chinese Academy of Sciences, Chinese Academy of Inspection and Quarantine and National Research Center for Environmental Analysis and Measurement
Type: | Journal: Journal of environmental sciences (China) | Year: 2017

Feed security is a prerequisite for safe animal food products. In this study, 13 groups of feed and feed ingredients, totaling 2067 samples, were collected in the period of 2011 to 2014 from China. The highest mean level of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) was found in fish meals and shell powders, with a concentration of 60.35ng/kg, followed by mineral origin materials. In terms of the toxicity equivalent concentration, the fish oil group showed the highest PCDD/F levels because of their bio-accumulation through the aquatic food chain, with an average concentration of 1.26ng WHO-TEQ/kg, while the lowest level was observed in compound feed for chickens and pigs, with an average value of 0.16ng WHO-TEQ/kg. OCDD and OCDF were the predominant congeners in all groups except fish oils, in which the primary congeners were 2,3,4,7,8-PeCDF and 2,3,7,8-TCDF. For zinc chloride samples, different from other zinc-based compound samples, the main congeners were 1,2,3,4,6,7,8-HpCDF (17%), 1,2,3,4,7,8,9-HpCDF (15%), 1,2,3,4,7,8-HxCDF (12%) and OCDF (30%). Considering toxicity equivalency factors, the dominant congeners were 2,3,4,7,8-PeCDF, 1, 2,3,4,7,8-HxCDF, 2,3,7,8-TCDF and 1,2,3,7,8-PeCDD, and the contribution to the total TEQ was 29%, 16%, 14% and 12%, respectively. Overall, 2.1% (43 out of 2067) of all the analyzed samples exceeded the different individual European Union maximum limited levels for PCDD/Fs. This study is beneficial for the determination of the status of contamination levels of feed and feed ingredients.


PubMed | University of Chinese Academy of Sciences, Chinese Academy of Inspection and Quarantine and National Research Center for Environmental Analysis and Measurement
Type: | Journal: Journal of environmental sciences (China) | Year: 2017

The health risk of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like PCBs (dl-PCBs) to human being should be assessed regularly. To evaluate the contamination levels in various food products in the Chinese market and to assess the dietary exposure of the Chinese population, 11 varieties of food groups totaling 634 samples including beef and mutton, chicken and duck, pork, fish and seafood, milk and dairy products were evaluated. The average concentrations of PCDD/Fs in all groups ranged from 0.291 to 8.468pg/g whole weight (w.w.). The average toxic equivalency concentrations were from 0.012pg TEQ/g w.w. for cereal to 0.367pg TEQ/g fat for marine oil. OCDD and 2,3,7,8-TCDF were the dominant congeners in foodstuffs. The dietary estimated mean intake for the Chinese rural and urban populations were 0.656 and 0.514pg TEQ/kg body weight/day, respectively, however, the cereal group exposure were higher to the estimate daily intake and contributed 81% for rural and 48% for urban population, followed by fish and seafood which contributed 4% and 16% to the estimate daily intake. The estimated dietary intakes were compared with the toxicological reference values and showed that both rural and urban populations were well below those values.

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