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Tang J.,Chinese Institute of Urban Environment | Tang J.,Chinese Academy of Sciences | Feng J.,Ningbo Environmental Monitoring Center | Li X.,Chinese Institute of Urban Environment | And 2 more authors.
Environmental Sciences: Processes and Impacts | Year: 2014

Hexabromocyclododecanes (HBCDs) and tetrabromobisphenol A (TBBPA) are of increasing concern because of their potential environmental persistence, bioaccumulation and toxicity. Tris-(2,3-dibromopropyl)isocyanurate (TBC) is another brominated flame retardant (BFR) which has recently been found in the environment and begun to attract attention. The objective of this study is to determine the concentration of these three BFRs in surface soil samples collected from a heavily industrialized and urbanized region in East China. Levels of ∑HBCDs ranged from below detection limits (0.020 ng g -1) to 102.6 ng g-1 on a dry weight basis (dw) with a median level of 15.8 ng g-1 dw. For TBBPA, the concentration ranged from below detection limits (0.025 ng g-1) to 78.6 ng g-1 dw with a median level of 9.17 ng g-1 dw. TBC was found at relatively lower concentrations ranging from below detection limits (0.024 ng g -1) to 16.4 ng g-1 dw with a median level of 0.95 ng g-1 dw. The concentrations of these three BFRs are significantly positively correlated, indicating a common source. Variable BFRs levels were found in different types of soils, with significantly higher concentrations observed at waste dumping sites and industrial areas. The diastereoisomer profiles of HBCDs in most of the soil samples differed from those of the commercial products. The mass inventories of HBCDs, TBBPA and TBC in this region gave preliminarily estimates of 6.68, 2.67 and 0.85 kg, respectively. Therefore, the ubiquitous contamination of soils by these BFRs may well reflect their widespread usage in the study area. This journal is © the Partner Organisations 2014. Source

Shao L.-N.,Lanzhou Jiaotong University | Ren Z.-M.,CAS Yantai Institute of Coastal Zone Research | Zhang G.-S.,CAS Yantai Institute of Coastal Zone Research | Chen L.-L.,CAS Yantai Institute of Coastal Zone Research | And 3 more authors.
Huanjing Kexue/Environmental Science | Year: 2011

To evaluate the contamination of Sn and Hg in the seafood in Yantai coastal areas, three kinds of wild shrimps and crabs were collected from three zones located in the coast in July, 2009. At the same time, seven kinds of mollusks were purchased from the local market. The concentrations of Sn and Hg in the samples were analyzed using an Agilent 7500i inductively coupled plasma-mass spectrometer (ICP-MS). The results showed that Sn and Hg concentrations in all the samples were different, with the ranges of 0.375-0.570 mg·kg-1 and 0.060-0.340 mg·kg-1(d. w.) and the average values of 0.470 and 0.140 mg·kg-1, respectively. For the mollusk samples, Concha ostreae was highly enriched with Sn, with the value of 0.570 mg·kg-1, while Mytilus edulis was obviously enriched with Hg, with the value of 0.340 mg·kg-1. The value of Pi was 1.13, which indicated that Mytilus edulis was seriously polluted. The concentrations of Sn and Hg in Chamys farreri and Sol sricus were the lowest, respectively. For the collected samples, the average concentrations of Sn and Hg in Oratosquilla oratoria, Alpheus brevicristatus and Carpilius convexus in the background area were all lower than those in sewage outfall area and port area, the average concentrations of Sn were 0.520 mg·kg-1(port area), 0.470 mg·kg-1(sewage outfall area) and 0.290 mg·kg-1(background area), the average concentrations of Hg were: 0.160 mg·kg-1(port area), 0.157 mg·kg-1(sewage outfall area) and 0.137 mg·kg-1(background area). Compared with other reports, the Sn level in the studied marine organisms was moderate, but the Hg level was a little higher. However, the concentrations of Sn and Hg in the studied marine seafood were all below the limit for agriculture product safety requirements for non-environmental pollution products, except Hg in Mytilus edulis (the national standards of Sn haven't been established).The results suggested that the coastal areas studied were not significantly polluted by the heavy metals of Sn and Hg. However, from the view of human health, people should consume the seafood away from the sewage outfall area and port area. Source

Wang T.,CAS Research Center for Eco Environmental Sciences | Han S.,CAS Research Center for Eco Environmental Sciences | Ruan T.,CAS Research Center for Eco Environmental Sciences | Wang Y.,CAS Research Center for Eco Environmental Sciences | And 2 more authors.
Chemosphere | Year: 2013

Hexabromocyclododecane (HBCD) is a high production volume brominated flame retardant (BFR) which has been of increasing environmental and public health concern due to its potential environmental persistency, bioaccumulation and toxicity. Tris-(2,3-dibromopropyl) isocyanurate (TBC) is another BFR which has recently been found in environmental matrices near a manufacturing plant, but its production volume and environmental distribution is currently not well known. This study was conducted to investigate the presence and distribution of these two BFRs in farm soils at a region in southeast Beijing. Total HBCD levels ranged from 0.17 to 34.5ngg-1 on a dry weight basis (dw) with a median level of 2.97ngg-1dw. The composition profile of HBCD diastereoisomers was, on average, 28%, 13% and 59% for α-, β- and γ-HBCD, respectively. Detection frequency of TBC was only 25% in 2010 but was detected in all soil samples in 2011, and the median level was 0.19ngg-1dw with the range between below detection limit to 1.62ngg-1dw. There were no significant differences of HBCD and TBC levels among different irrigation sources in the region. The soil HBCD and TBC levels in samples collected in 2011 were significantly higher than in 2010. The increasing short-term temporal levels in farm soil might be due to the rapid urbanization in this region or could also reflect the increasing usage of HBCD and TBC after the phase out of other BFRs. © 2012. Source

Zheng W.-W.,Nankai University | Bi X.-H.,Nankai University | Wu J.-H.,Nankai University | Feng Y.-C.,Nankai University | And 3 more authors.
Research of Environmental Sciences | Year: 2014

Ambient volatile organic compound (VOCs) samples were collected from three sites (urban area, Zhenhai and Beilun) in Ningbo during 2010. A total of 36 VOC species were determined. The chemical composition and spatiotemporal variations of ambient VOCs were investigated. Key reactive species of VOCs were identified based upon OH radical reaction rate (LOH). The average mass concentration of the total VOCs (sum of 36 VOCs) was 198.2 μg/m3, and the major components were alkanes (48.6%), aromatics (33.6%) and alkenes (17.8%). Seasonal concentrations of the total VOCs (ρ (VOCs)) were ordered as winter (298.5 μg/m3) 〉 autumn (174.1 μg/m3) 〉 spring (122.0 μg/m3). ρ (VOCs) in the urban area (161.3 μg/m3) was lower than those in Zhenhai (225.0 μg/m3) and Beilun (208.2 μg/m3). The relative compositions of the total VOCs were stable. Having the similar LOH to ethylene, the chemical reactivity of total VOCs was relatively strong. Alkenes, being only 22% of the mixing ratio of VOCs, contributed the most to LOH and accounted for over 64% of chemical reactivity. The key reactive species of ambient VOCs were 1-butene, trans-2-butene, m, p-xylene, ethylene and pentene. ©, 2014, Editorial Department of Molecular Catalysis. All right reserved. Source

Du B.-H.,University of Science and Technology of China | Huang X.-F.,University of Science and Technology of China | He L.-Y.,University of Science and Technology of China | Hu M.,Peking University | And 6 more authors.
Huanjing Kexue/Environmental Science | Year: 2015

To investigate the seasonal and spatial variations of carbon fractions in PM2.5 in Ningbo, PM2.5 samples were collected at 5 sites in typical periods of 4 seasons from December 2012 to October 2013. The concentrations of organic carbon (OC) and elemental carbon (EC) were determined and the contribution of secondary organic carbon (SOC) was estimated. The result shows that: (1) the annual average of PM2.5 in Ningbo is 51.6 μg·m-3. OC and EC account for 17% and 6% respectively. According to the result of the backward trajectory model, the concentrations of PM2.5 in winter and spring are higher mainly because of regional transport from inland China. (2) the OC/EC ratio and the correlation between OC and EC indicate that in summer a large sum of SOC is generated while in winter the influence of coal burning emission for heating in North China may be the main reason for high OC/EC ratio. (3) the contribution of SOC was estimated using an EC tracer method. The result shows that this method is not suitable for both winter and spring because of significant regional transport. The average concentrations of SOC in summer and autumn are 2.5 μg·m-3 and 2.3 μg·m-3, accounting for 42% and 28% of total OC respectively. ©, 2015, Science Press. All right reserved. Source

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