Size-resolved chemical compositions of non-refractory submicron aerosols were measured using a quadrupole Aerodyne aerosol mass spectrometer at a rural site near Guangzhou in the Pearl River Delta (PRD) of China in the summer of 2006. Two cases characterized as the outflows from the PRD urban region with plumes of high SO2 concentration were investigated. The evolution of sulfate size distributions was observed on a timescale of several hours. Namely mass concentrations of sulfate in the condensation mode (with vacuum aerodynamic diameters (Dva) < 300 nm) increased at a rate of about 0.17–0.37 ppbv h?1 during the daytime. This finding was consistent with the sulfuric acid production rates of about 0.17–0.3 ppbv h?1, as calculated from the observed gas-phase concentrations of OH (~3.3 × 106–1.7 × 107 cm?3) and SO2 (~3–21.2 ppbv). This implies that the growth of sulfate in the condensation mode was mainly due to gas-phase oxidation of SO2. The observed rapid increase was caused mainly by the concurrent high concentrations of OH and SO2 in the air mass. The evolution of the mass size distributions of m/z 44, a tracer for oxygenated organic aerosol (OOA), was very similar to that of sulfate. The mass loadings of m/z 44 were strongly correlated with those of sulfate (r2 = 0.99) in the condensation mode, indicating that OOA might also be formed by the gas-phase oxidation of volatile organic compound (VOC) precursors. It is likely that sulfate and OOA were internally mixed throughout the whole size range in the air mass. 相似文献
The association between co-exposure to multiple metals and renal function is poorly understood. We aimed to evaluate the individual and joint effects of metal exposure on renal function in this study. We performed a cross-sectional study including 5828 participants in Guangxi, China, in 2019. Urine concentrations of 17 metals were detected by inductively coupled plasma mass spectrometry (ICP-MS). Logistic regression model and restricted cubic spline (RCS) were applied to investigate the association of individual metal exposure with renal dysfunction. Weighted quantile sum (WQS) regression and Bayesian kernel machine regression (BKMR) were used to assess the co-exposure effects of the metals. Participants with the highest quartile of urinary Cu were at 1.84-fold (95% confidence interval (CI): 1.20–2.87) increased risk of renal dysfunction compared with the lowest quartile. The highest quartiles of urinary Sr, Cs, V, Ba, and Se were associated with 0.27-fold (95% CI: 0.17–0.43), 0.33 (95% CI: 0.19–0.53), 0.41 (95% CI: 0.25–0.65), 0.58 (95% CI: 0.36–0.90), and 0.33 (95% CI: 0.19–0.56) decreased risk of renal dysfunction compared with their lowest quartile, respectively. Furthermore, urinary Ba and Cu were non-linearly correlated with renal dysfunction. The WQS analysis showed that mixed metal exposure was inversely associated with renal dysfunction (OR = 0.47, 95% CI: 0.35–0.62), and Sr accounted for the largest weight (52.2%), followed by Cs (32.3%) in the association. Moreover, we observed a potential interaction between Cu, Cs, and Ba for renal dysfunction in BKMR model. Exposure to Se, Sr, Cs, V, and Ba is associated with decreased risk of renal dysfunction, whereas an increased risk is associated with Cu exposure. Co-exposure to these metals is negatively associated with renal dysfunction, and Sr and Cs are the main contributors to the associations.
Environmental Chemistry Letters - Nanosilver (nAg) is increasingly being used in a wide array of fields, and its toxicity has been extensively studied. Here we present a review of environmental nAg... 相似文献
Environmental Science and Pollution Research - To investigate the relationship between health effect profile and co-exposure to heavy metal, 254 sanitation workers from Guangzhou, China, were... 相似文献
Environmental Geochemistry and Health - The purpose of this study was to investigate the associations between levels of lead (Pb), cadmium (Cd), chromium (Cr), and manganese (Mn) in the PM2.5 and... 相似文献
Environmental Science and Pollution Research - A recent work has shown that hydrophobic organic compounds solubilized in the micelle phase of some nonionic surfactants present substrate toxicity to... 相似文献
In the construction industry, contractors have been facing the challenge to meet the emerging needs related to the reduction of environmental impacts during the construction process. Generally, the commitment of efforts and resources from contractors to meet these needs is motivated by the influence exerted from environmental regulations and stakeholder demands. However, managerial environmental concerns and size of firms also account as key factors affecting the adoption of green construction practices. Therefore, the aim of this research is to identify those factors influencing contractors to adopt green construction practices by using data gathered from a survey. From the results, it has been found that managerial concern is the most important driver for the adoption of green practices. Significant relationships have also been found between government regulations and business size with the adoption of green construction practices. However, there is no significant evidence on the relationship among the adoption of green construction practices with perceived stakeholders’ pressures. The findings from this study are significant in the understanding on the factors of green construction management. This knowledge may contribute to better decision-making towards implementing green construction practices. 相似文献
Culling feral camels will impact on the carbon emissions from them. Culling of feral camels stops their long-term continuous methane emission, but emits carbon from their carcasses in the short term. Through on-site monitoring of the decomposition process of camels that have been shot dead, this paper models the pattern of carbon emissions during the decomposition of these camels in Central Australia, and analyses the contribution of the camel culling programme to carbon emission mitigation on the rangelands. A ‘carbon royalty’ payment mechanism is also suggested to encourage local participation in carbon markets through an involvement in natural resource management. 相似文献