The occurrence and risks of Giardia in China have been unclear to date,which has made it difficult to properly manage source water as well as to create reasonable drinking water standards.The levels of Giardia in rive...The occurrence and risks of Giardia in China have been unclear to date,which has made it difficult to properly manage source water as well as to create reasonable drinking water standards.The levels of Giardia in river networks of several cities in Zhejiang Province,China were found to be in the range of 0-5 oocysts/10 L in the rainy season in 2008.The mortality due to Giardia infection for people in this region was calculated to be from 0 to 1.95 × 10？8 persons using a conditional probability equation.Based on multiple unboiled water intake routes,the disability-adjusted life years（DALYs） due to Giardia infection for people who consumed conventionally treated water was 0.625（95% CI：0.137-2.05） per 105 persons,with the symptom of hospitalization making the highest contribution to total DALYs（0.56 per 105 persons;95% CI：0.122-1.84）.The DALYs decreased to 0.425（95% CI：0.137-2.05） per 105 persons per year for those consuming water treated with advanced technology.These values were lower than the acceptable risk（1.97 × 10？5 DALYs per year）.This study revealed the risk of Giardia infection to the people in river networks of Zhejiang Province for the first time,and provides a method to evaluate the risk of Giardia infection.The results are useful for the modification of drinking water quality standards based on cost-benefit analysis.展开更多
Despite recent efforts to investigate the distribution and fate of polycyclic aromatic hydrocarbons （PAHs） in air, water, and soil, very little is known about their temporal change in wet deposition. As a result of ...Despite recent efforts to investigate the distribution and fate of polycyclic aromatic hydrocarbons （PAHs） in air, water, and soil, very little is known about their temporal change in wet deposition. As a result of increased attention to public health, a large-scale survey on the deposition flux and distribution of PAH contamination in rainwater was urgently conducted in Shanghai, China. In this study, 163 rainwater samples were collected from six sites, and 15 PAH compounds were detected by the use of a simple solid phase microextraction （SPME） technique coupled with gas chromatography-mass spectrometry. The dominant PAH species monitored were naphthalene, phenanthrene, anthracene, and fluoranthene. The concentration of total PAHs per event was between 74 and 980 ng/L, with an average value of 481 ng/L, which is at the high end of worldwide figures. The annual deposition flux of PAHs in rainwater was estimated to be 4148 kg/yr in the Shanghai area, suggesting rainfall as a major possible pathway for removing PAHs from the atmosphere. Diagnostic analysis by the ratios of An/178 and Fl/Fl＋Py suggested that combustion of grass, wood, and coal was the major contributor to PAHs in the Shanghai region. Back trajectory analysis also indicated that the pollutant sources could be from the southern part of China.展开更多
基金supported by the Foundation of Major Science and Technology Program for Water Pollution Control and Treatment (No. 2009ZX07419-002)the National Natural Science Foundation of China (No. 50778171,50809066, 20807013)
文摘The occurrence and risks of Giardia in China have been unclear to date,which has made it difficult to properly manage source water as well as to create reasonable drinking water standards.The levels of Giardia in river networks of several cities in Zhejiang Province,China were found to be in the range of 0-5 oocysts/10 L in the rainy season in 2008.The mortality due to Giardia infection for people in this region was calculated to be from 0 to 1.95 × 10？8 persons using a conditional probability equation.Based on multiple unboiled water intake routes,the disability-adjusted life years（DALYs） due to Giardia infection for people who consumed conventionally treated water was 0.625（95% CI：0.137-2.05） per 105 persons,with the symptom of hospitalization making the highest contribution to total DALYs（0.56 per 105 persons;95% CI：0.122-1.84）.The DALYs decreased to 0.425（95% CI：0.137-2.05） per 105 persons per year for those consuming water treated with advanced technology.These values were lower than the acceptable risk（1.97 × 10？5 DALYs per year）.This study revealed the risk of Giardia infection to the people in river networks of Zhejiang Province for the first time,and provides a method to evaluate the risk of Giardia infection.The results are useful for the modification of drinking water quality standards based on cost-benefit analysis.
基金supported by the National Natural Science Foundation of China (No. 21177025, 40705045, 40875073, 40728006)the New-teacher Fund for Ph.D Studies of Ministry of Education of China (No. 20070246029)+2 种基金the Science & Technology Commission of Shanghai Municipality (No.09160707700)the Key Project from Ministry of Education of China (No. 108050)the State Key Laboratory of Pollution Control and Resource Reuse Foundation (No. PCRRF1011)
文摘Despite recent efforts to investigate the distribution and fate of polycyclic aromatic hydrocarbons （PAHs） in air, water, and soil, very little is known about their temporal change in wet deposition. As a result of increased attention to public health, a large-scale survey on the deposition flux and distribution of PAH contamination in rainwater was urgently conducted in Shanghai, China. In this study, 163 rainwater samples were collected from six sites, and 15 PAH compounds were detected by the use of a simple solid phase microextraction （SPME） technique coupled with gas chromatography-mass spectrometry. The dominant PAH species monitored were naphthalene, phenanthrene, anthracene, and fluoranthene. The concentration of total PAHs per event was between 74 and 980 ng/L, with an average value of 481 ng/L, which is at the high end of worldwide figures. The annual deposition flux of PAHs in rainwater was estimated to be 4148 kg/yr in the Shanghai area, suggesting rainfall as a major possible pathway for removing PAHs from the atmosphere. Diagnostic analysis by the ratios of An/178 and Fl/Fl＋Py suggested that combustion of grass, wood, and coal was the major contributor to PAHs in the Shanghai region. Back trajectory analysis also indicated that the pollutant sources could be from the southern part of China.
