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Contamination and source differentiation of Pb in park soils along an urban–rural gradient in Shanghai Full text
2011
Li, Hong-bo | Yu, Shen | Li, Gui-lin | Deng, Hong | Luo, Xiao-san
Urban soil Pb contamination is a great human health risk. Lead distribution and source in topsoils from 14 parks in Shanghai, China were investigated along an urban–rural gradient. Topsoils were contaminated averagely with 65 mg Pb kg⁻¹, 2.5 times higher than local soil background concentrations. HCl-extracts contained more anthropogenic Pb signatures than total sample digests as revealed by the higher ²⁰⁷/²⁰⁶Pb and ²⁰⁸/²⁰⁶Pb ratios in extracts (0.8613 ± 0.0094 and 2.1085 ± 0.0121 versus total digests 0.8575 ± 0.0098 and 2.0959 ± 0.0116). This suggests a higher sensitivity of HCl-extraction than total digestion in identifying anthropogenic Pb sources. Coal combustion emission was identified as the major anthropogenic Pb source (averagely 47%) while leaded gasoline emission contributed 12% overall. Urbanization effects were observed by total Pb content and anthropogenic Pb contribution. This study suggests that to reduce Pb contamination, Shanghai might have to change its energy composition to clean energy.
Show more [+] Less [-]Assessing estrogenic activity in surface water and sediment of the Liao River system in northeast China using combined chemical and biological tools Full text
2011
This paper investigated some selected estrogenic compounds (4-t-octylphenol: 4-t-OP; 4-nonylphenols: 4-NP; bisphenol-A: BPA; diethylstilbestrol: DES; estrone: E1; 17β-estradiol: E2; 17α-Ethinylestradiol: EE2; triclosan: TCS) and estrogenicity in the Liao River system using the combined chemical and in vitro yeast screen bioassay and assessed their ecological risks to aquatic organisms. The estrogenic compounds 4-t-OP, 4-NP, BPA, E1, E2 and TCS were detected in most of the samples, with their concentrations up to 52.1 2065.7, 755.6, 55.8, 7.4 and 81.3ng/L in water, and up to 8.6, 558.4, 33.8, 7.9, <LOQ and 33.9ng/g in sediment, respectively. However, DES and EE2 were not detected in the Liao River. The estrogen equivalents (EEQ) of the water and sediment samples were also measured by the bioassay. High estrogenic risks to aquatic organisms were found in the river sections of metropolitan areas and the lower reach of the river system.
Show more [+] Less [-]National survey of the levels of persistent organochlorine pesticides in the breast milk of mothers in China Full text
2011
Zhou, Pingping | Wu, Yongning | Yin, Shian | Li, Jingguang | Zhao, Yunfeng | Zhang, Lei | Chen, Huijing | Liu, Yinping | Yang, Xin | Li, Xiaowei
The occurrence of persistent organochlorine pesticides (OCPs) in breast milk samples collected from mothers from twelve provinces in mainland China was investigated. Dichlorodiphenyltrichloroethanes (DDTs) were the most prevalent agent, followed by HCHs and HCB, whereas levels of chlordane compounds, drins and mirex were lower. The relatively lower DDE/DDT ratio in the Fujian rural area suggested more recent exposure to DDT than in other areas. The mean level of DDTs in breast milk from the southern China was higher than those from northern China (p < 0.05). A positive correlation was observed between concentration of DDTs in human milk and consumption of animal-origin food, suggesting that this parameter could play an important part in influencing OCPs burdens in lactating women. The mean estimated daily intakes of different OCPs for breastfed infants were lower than the tolerable daily intake.
Show more [+] Less [-]Dechlorane Plus (DP) in air and plants at an electronic waste (e-waste) site in South China Full text
2011
Chen, She-Jun | Tian, Mi | Wang, Jing | Shi, Tian | Luo, Yong | Luo, Xiao-Jun | Mai, Bi-Xian
Air and foliage samples (Eucalyptus spp. and Pinus massoniana Lamb.) were collected from e-waste and reference sites in South China and analyzed for Dechlorane Plus (DP) and two dechlorinated DPs. DP concentrations in the air were 13.1–1794 pg/m³ for the e-waste site and 0.47–35.7 pg/m³ for the reference site, suggesting the recycling of e-waste is an important source of DP to the environment. Plant DP, with concentrations of 0.45–51.9 ng/g dry weight at the e-waste site and 0.09–2.46 ng/g at the reference site, exhibited temporal patterns similar to the air DP except for pine needle at the reference site. The air-plant exchange of DP could be described with the two-compartment model. Anti-Cl₁₁ DP was measured in most air and plant samples from the e-waste site. The ratios of anti-Cl₁₁ DP to anti-DP in the air and plants may indicate the preferential uptake of dechlorinated DP by plant compared with DP.
Show more [+] Less [-]Water, heat, and airborne pollutants effects on transpiration of urban trees Full text
2011
Wang, Hua | Ouyang, Z. (Zhiyun) | Chen, Weiping | Wang, Xiaoke | Zheng, Hua | Ren, Yufen
Transpiration rates of six urban tree species in Beijing evaluated by thermal dissipation method for one year were correlated to environmental variables in heat, water, and pollutant groups. To sort out colinearity of the explanatory variables, their individual and joint contributions to variance of tree transpiration were determined by the variation and hierarchical partitioning methods. Majority of the variance in transpiration rates was associated with joint effects of variables in heat and water groups and variance due to individual effects of explanatory group were in comparison small. Atmospheric pollutants exerted only minor effects on tree transpiration. Daily transpiration rate was most affected by air temperature, soil temperature, total radiation, vapor pressure deficit, and ozone. Relative humidity would replace soil temperature when factors influencing hourly transpiration rate was considered.
Show more [+] Less [-]Levels and sources of brominated flame retardants in human hair from urban, e-waste, and rural areas in South China Full text
2011
Zheng, Jing | Luo, Xiao-Jun | Yuan, Jian-Gang | Wang, Jing | Wang, Yu-Tao | Chen, Shen-Jun | Mai, Bi-Xian | Yang, Zhong-Yi
Human hair and indoor dust from urban, e-waste, and rural areas in south China were collected and analyzed for brominated flame retardants (BFRs). BFRs concentrations in hair from occupational e-waste recycling workers were higher than those from non-occupational exposed residents in other sampling areas. Polybrominated diphenyl ethers (PBDEs) and decabromodiphenyl ethane (DBDPE) are two major BFRs in hair samples. The PBDE congener profiles in hair from the e-waste area are different from those from urban and rural areas with relatively higher contribution of lower brominated congeners. DBDPE, instead of BDE209, has become the major BFR in non-e-waste recycling areas. Significant correlations were found between hair level and dust level for DBDPE and BTBPE but not for PBDEs. The different PBDE congener profiles between dust and hair may suggest that exogenous exposure to the PBDE adsorbed on dust is not a major source of hair PBDEs.
Show more [+] Less [-]Carbon savings resulting from the cooling effect of green areas: A case study in Beijing Full text
2011
Lin, Wenqi | Wu, Tinghai | Zhang, Chengguo | Yu, Ting
Green areas cool the climate of a city, reduce the energy consumption caused by the urban heat island (UHI) effect, and bring along carbon savings. However, the calculation of carbon savings due to the cooling effect of green areas is still not well understood. We have used a Landsat Enhanced Thematic Mapper Plus (ETM+) image of Beijing, to identify the cooled areas, compute the possible energy used to maintain the temperature differences between cooled areas and their surrounding heated areas, and calculate the carbon savings owing to the avoidance of energy use. Results show that a total amount of 14315.37 tons carbon savings was achieved in the study area and the amount was related to the biomass, the size and the shape of green areas. These results demonstrate the importance of carbon savings resulting from green areas' cooling effect.
Show more [+] Less [-]Concentrations and assessment of exposure to siloxanes and synthetic musks in personal care products from China Full text
2011
Lu, Yan | Yuan, Tao | Wang, Wenhua | Kannan, Kurunthachalam
We investigated the concentrations and profiles of 15 siloxanes (four cyclic siloxanes, D₄–D₇; 11 linear siloxanes, L₄–L₁₄), four synthetic musks (two polycyclic musks, HHCB and AHTN; two nitro musks, MX and MK), and HHCB-lactone, in 158 personal care products marketed in China. Siloxanes were detected in 88% of the samples analyzed, at concentrations as high as 52.6 mg g⁻¹; Linear siloxanes were the predominant compounds. Among synthetic musks, more than 80% of the samples contained at least one of these compounds, and their total concentrations were as high as 1.02 mg g⁻¹. HHCB was the predominant musk in all of the samples analyzed, on average, accounting for 52% of the total musk concentrations. Based on the median concentrations of siloxanes and musks and the average daily usage amounts of consumer products, dermal exposure rates in adults were calculated to be 3.69 and 3.38 mg d⁻¹ for siloxanes and musks, respectively.
Show more [+] Less [-]Sources and distribution of polychlorinated-dibenzo-p-dioxins and -dibenzofurans in soil and sediment from the Yellow Sea region of China and Korea Full text
2011
Naile, Jonathan E. | Khim, Jong Seong | Wang, Tieyu | Wan, Yi | Luo, Wei | Hu, Wenyou | Jiao, Wentao | Park, Jinsoon | Ryu, Jongseong | Hong, Seongjin | Jones, Paul D. | Lü, Yonglong | Giesy, John P.
Polychlorinated-dibenzo-p-dioxins and -dibenzofurans (PCDD/Fs) were measured in soils and sediments from the Yellow Sea region. Korean soils and sediments mostly contained detectable PCDD/Fs and showed a widespread distribution among locations. Soil and sedimentary PCDD/Fs from China were comparable to or less than those in Korea. The patterns of relative concentrations of individual congeners in soils were different between the two countries, but similar in sediments. Sources of PCDD/Fs in China and Korea were found to be independent of each other and their distributions reflected matrix-dependent accumulation. Spatial distribution indicated some point sources in Korea while Chinese sources were more widespread and diffuse. PCDD/Fs measured in the coastal areas of the Yellow Sea were comparable to or less than those previously reported in for eastern Asia. However, ∑TEQs in soils and sediments were near to or, in some cases exceeded environmental quality guidelines.
Show more [+] Less [-]Historical estimation of carbonaceous aerosol emissions from biomass open burning in China for the period 1990–2005 Full text
2011
Qin, Y. | Xie, S.D.
Multi-year inventories of carbonaceous aerosol emissions from biomass open burning at a high spatial resolution of 0.5° × 0.5° have been constructed in China using GIS methodology for the period 1990–2005. Black carbon (BC) emissions have increased by 383.03% at an annual average rate of 25.54% from 14.05 Gg in 1990 to 67.87 Gg in 2005; while organic carbon (OC) emissions have increased by 365.43% from 57.37 Gg in 1990 to 267.00 Gg in 2005. Through the estimation period, OC/BC ratio for biomass burning was averagely 4.09, suggesting that it was not the preferred control source from a climatic perspective. Spatial distribution of BC and OC emissions were similar, mainly concentrated in three northeastern provinces, central provinces of Shandong, Jiangsu, Anhui and Henan, and southern provinces of Guangxi, Guangdong, Hunan and Sichuan basin, covering 24.89% of China’s territory, but were responsible for 63.38% and 67.55% of national BC and OC emissions, respectively.
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