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Passive air sampling of organochlorine pesticides and polychlorinated biphenyls in the Yangtze River Delta, China: Concentrations, distributions, and cancer risk assessment 全文
2013
Zhang, Lifei | Dong, Liang | Yang, Wenlong | Zhou, Li | Shi, Shuangxin | Zhang, Xiulan | Niu, Shan | Li, Lingling | Wu, Zhongxiang | Huang, Yeru
The Yangtze River Delta (YRD) has been quickly industrialized and urbanized. Passive air sampling of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) was carried out in the YRD in 2010–2011 to investigate their spatiotemporal distributions and estimate the risk of cancer from their inhalation. Annual concentrations were 151, 168, 18.8, 110, 17.9, and 35.0 pg m−3 for HCB, ∑DDTs, ∑HCHs, ∑chlordane, mirex, and PCBs, respectively. The highest OCP and PCB concentrations were generally detected in the autumn and winter. The average concentrations of OCPs and PCBs for the different site groups followed the order urban ≈ urban–rural transition > rural. The lifetime excess cancer risks from the inhalation of OCPs and PCBs were <1.0 × 10−6. The predicted cancer cases per lifetime associated with the inhalation of OCPs and PCBs are 12, 7, and 4 per ten thousand people for urban, urban–rural transition, and rural areas, respectively.
显示更多 [+] 显示较少 [-]Effects of dietary selenium on the health and survival of captive wintering lesser scaup 全文
2013
Brady, Caroline | Petrie, Scott | Schummer, Michael | Badzinski, Shannon | Belzile, Nelson | Chen, Yu-Wei
Accumulation of selenium (Se) by lesser and greater scaup (Aythya affinis, A. marila) at staging and wintering areas could have contributed to the decline in their continental population. We exposed lesser scaup to background (0.8 μg/g), moderate (8.1 μg/g) and high (20.7 μg/g) levels of dietary Se in captivity and measured survival rates and indices of health in relation to hepatic Se concentrations. There was 100% survival in scaup exposed to Se for 10-weeks (average staging duration at Great Lakes), but ducks in the high treatment group had less lipids. There was 93% survival after 23-weeks (average wintering duration at Great Lakes), but no differences among treatment groups in body composition. There were no effects of Se on oxidative stress and cell-mediated immunity; rather we recorded immuno-stimulatory effects on antibody production. Results from our captive study suggest Se alone did not cause the continental decline in scaup populations.
显示更多 [+] 显示较少 [-]Does urban vegetation mitigate air pollution in northern conditions? 全文
2013
Setälä, Heikki | Viippola, Viljami | Rantalainen, Anna-Lea | Pennanen, Arto | Yli-Pelkonen, Vesa
It is generally accepted that urban vegetation improves air quality and thereby enhances the well-being of citizens. However, empirical evidence on the potential of urban trees to mitigate air pollution is meager, particularly in northern climates with a short growing season. We studied the ability of urban park/forest vegetation to remove air pollutants (NO2, anthropogenic VOCs and particle deposition) using passive samplers in two Finnish cities. Concentrations of each pollutant in August (summer; leaf-period) and March (winter, leaf-free period) were slightly but often insignificantly lower under tree canopies than in adjacent open areas, suggesting that the role of foliage in removing air pollutants is insignificant. Furthermore, vegetation-related environmental variables (canopy closure, number and size of trees, density of understorey vegetation) did not explain the variation in pollution concentrations. Our results suggest that the ability of urban vegetation to remove air pollutants is minor in northern climates.
显示更多 [+] 显示较少 [-]Effects of elevated O3 exposure on nutrient elements and quality of winter wheat and rice grain in Yangtze River Delta, China 全文
2013
Zheng, Feixiang | Wang, Xiaoke | Zhang, Weiwei | Hou, Peiqiang | Lu, Fei | Du, Keming | Sun, Zhongfu
With the open-top chambers (OTCs) in situ in Yangtze River Delta, China in 2007 and 2008, the effects of elevated O3 exposure on nutrient elements and quality of winter wheat and rice grain were investigated. Grain yield per plant of winter wheat and rice declined in both years. The N and S concentrations increased under elevated O3 exposure in both years and C–N ratios decreased significantly. The concentrations of K, Ca, Mg, P, Mn, Cu and Zn in winter wheat and the concentrations of Mg, K, Mn and Cu in rice increased. The concentrations of protein, amino acid and lysine in winter wheat and rice increased and the concentration of amylose decreased. The increase in the nutrient concentration was less than the reduction of grain yield in both winter wheat and rice, and, hence, the absolute amount of the nutrients was reduced by elevated O3.
显示更多 [+] 显示较少 [-]Source contributions to carbonaceous species in PM2.5 and their uncertainty analysis at typical urban, peri-urban and background sites in southeast China 全文
2013
Niu, Zhenchuan | Wang, Sen | Chen, Jinsheng | Zhang, Fuwang | Chen, Xiaoqiu | He, Chi | Lin, Lifeng | Yin, Liqian | Xu, Lingling
Determination of 14C and levoglucosan can provide insights into the quantification of source contributions to carbonaceous aerosols, yet there is still uncertainty on the partitioning of organic carbon (OC) into biomass burning OC (OCbb) and biogenic emission OC (OCbio). Carbonaceous species, levoglucosan and 14C in PM2.5 were measured at three types of site in southeast China combined with Latin hypercube sampling, with the objectives to study source contributions to total carbon (TC) and their uncertainties, and to evaluate the influence of levoglucosan/OCbb ratios on OCbb and OCbio partitioning. It was found reliably that fossil fuel combustion is the main contributor (62.90–72.23%) to TC at urban and peri-urban sites. Biogenic emissions have important contribution (winter, 52.98%; summer, 45.71%) to TC at background site. With the increase in levoglucosan/OCbb ratios, the contribution of OCbio is increased while OCbb is decreased in a pattern of approximate natural logarithm at a given range.
显示更多 [+] 显示较少 [-]Nature and sources of particle associated polycyclic aromatic hydrocarbons (PAH) in the atmospheric environment of an urban area 全文
2013
Callén, M.S. | López, J.M. | Iturmendi, A. | Mastral, A.M.
The total PAH associated to the airborne particulate matter (PM10) was apportioned by one receptor model based on positive matrix factorization (PMF) in an urban environment (Zaragoza city, Spain) during February 2010–January 2011. Four sources associated with coal combustion, gasoline, vehicular and stationary emissions were identified, allowing a good modelling of the total PAH (R2 = 0.99). A seasonal behaviour of the four factors was obtained with higher concentrations in the cold season. The NE direction was one of the predominant directions showing the negative impact of industrial parks, a paper factory and a highway located in that direction. Samples were classified according to hierarchical cluster analysis obtaining that, episodes with the most negative impact on human health (the highest lifetime cancer risk concentrations), were produced by a higher contribution of stationary and vehicular emissions in winter season favoured by high relative humidity, low temperature and low wind speed.
显示更多 [+] 显示较少 [-]Distributions and sea-to-air fluxes of chloroform, trichloroethylene, tetrachloroethylene, chlorodibromomethane and bromoform in the Yellow Sea and the East China Sea during spring 全文
2013
He, Zhen | Yang, Gui-Peng | Lu, Xiao-Lan | Zhang, Hong-Hai
Halocarbons including chloroform (CHCl3), trichloroethylene (C2HCl3), tetrachloroethylene (C2Cl4), chlorodibromomethane (CHBr2Cl) and bromoform (CHBr3) were measured in the Yellow Sea (YS) and the East China Sea (ECS) during spring 2011. The influences of chlorophyll a, salinity and nutrients on the distributions of these gases were examined. Elevated levels of these gases in the coastal waters were attributed to anthropogenic inputs and biological release by phytoplankton. The vertical distributions of these gases in the water column were controlled by different source strengths and water masses. Using atmospheric concentrations measured in spring 2012 and seawater concentrations obtained from this study, the sea-to-air fluxes of these gases were estimated. Our results showed that the emissions of C2HCl3, C2Cl4, CHBr2Cl, and CHBr3 from the study area could account for 16.5%, 10.5%, 14.6%, and 3.5% of global oceanic emissions, respectively, indicating that the coastal shelf may contribute significantly to the global oceanic emissions of these gases.
显示更多 [+] 显示较少 [-]Does plant uptake or low soil mineral-N production limit mineral-N losses to surface waters and groundwater from soils under grass in summer? 全文
2013
Bhatti, Ambreen | McClean, Colin J. | Cresser, Malcolm S.
Summer minima and autumn/winter maxima in nitrate concentrations in rivers are reputedly due to high plant uptake of nitrate from soils in summer. A novel alternative hypothesis is tested here for soils under grass. By summer, residual readily mineralizable plant litter from the previous autumn/winter is negligible and fresh litter input low. Consequently little mineral-N is produced in the soil. Water-soluble and KCl-extractable mineral N in fresh soils and soils incubated outdoors for 7 days have been monitored over 12 months for soil transects at two permanent grassland sites near York, UK, using 6 replicates throughout. Vegetation-free soil is shown to produce very limited mineral-N in summer, despite the warm, moist conditions. Litter accumulates in autumn/winter and initially its high C:N ratio favours N accumulation in the soil. It is also shown that mineral-N generated monthly in situ in soil substantially exceeds the monthly mineral-N inputs via wet deposition at the sites.
显示更多 [+] 显示较少 [-]Particle size, chemical composition, seasons of the year and urban, rural or remote site origins as determinants of biological effects of particulate matter on pulmonary cells 全文
2013
Perrone, M.G. | Gualtieri, M. | Consonni, V. | Ferrero, L. | Sangiorgi, G. | Longhin, E. | Ballabio, D. | Bolzacchini, E. | Camatini, M.
Particulate matter (PM), a complex mix of chemical compounds, results to be associated with various health effects. However there is still lack of information on the impact of its different components. PM2.5 and PM1 samples, collected during the different seasons at an urban, rural and remote site, were chemically characterized and the biological effects induced on A549 cells were assessed. A Partial Least Square Discriminant Analysis has been performed to relate PM chemical composition to the toxic effects observed. Results show that PM-induced biological effects changed with the seasons and sites, and such variations may be explained by chemical constituents of PM, derived both from primary and secondary sources. The first-time here reported biological responses induced by PM from a remote site at high altitude were associated with the high concentrations of metals and secondary species typical of the free tropospheric aerosol, influenced by long range transports and aging.
显示更多 [+] 显示较少 [-]Global climate change: Impact of diurnal temperature range on mortality in Guangzhou, China 全文
2013
Yang, Jun | Liu, Hua-Zhang | Ou, Chun-Quan | Lin, Guo-Zhen | Zhou, Qin | Shen, Gi-Chuan | Chen, Ping-Yan | Guo, Yuming
Diurnal temperature range (DTR) is an important meteorological indicator associated with global climate change, but little is known about the effects of DTR on mortality. We examined the effects of DTR on cause-/age-/education-specific mortality in Guangzhou, a subtropical city in China during 2003–2010. A quasi-Poisson regression model combined with distributed lag non-linear model was used to examine the effects of DTR, after controlling for daily mean temperature, air pollutants, season and day of the week. A 1 °C increase in DTR at lag 0–4 days was associated with a 0.47% (95% confidence interval: 0.01%–0.93%) increase in non-accidental mortality. Stroke mortality was most sensitive to DTR. Female, the elderly and those with low education were more susceptible to DTR than male, the youth and those with high education, respectively. Our findings suggest that vulnerable subpopulations should pay more attention to protect themselves from unstable daily weather.
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