ABSTRACT
Objective@#To evaluate health risks of five heavy metals in drinking water of rural schools in Henan Province, so as to provide scientific basis for drinking water safety in rural schools.@*Methods@#Totally 1 269 drinking water samples were collected and analyzed for five heavy metals (As, Cd, Cr 6+ , Pb, Hg) concentration in 106 cities and counties of Henan Province, and its spatial distribution characteristics were explored by geographic information system (GIS). Risk assessment method recommended by the United States Environmental Protection Agency (U.S. EPA) was applied to evaluate health risks from five heavy metals through oral ingestion.@*Results@#The qualified rate of As concentration was 100%, and the qualified rates of Cd, Cr 6+ , Pb and Hg were 99.9% , 99.9%, 99.5%, 99.6%. The highest carcinogenic risk was As (3.05×10 -5 ), followed by Cr 6+ (2.73×10 -5 ), and the highest non carcinogenic risk was As (0.158 3), followed by Pb(0.041 7). The carcinogenic risk and non carcinogenic risk were all higher in girls than boys. The carcinogenic and non carcinogenic risks were differences in different regions( P <0.05).@*Conclusion@#Health risks of five heavy metals in drinking water for rural schools in Henan Province were within the acceptable risk level recommended by EPA. As, Cr 6+ and Pb were the main health risk factors in drinking water, and that might impact negatively the healthy growth of primary and middle school students. These should be future efforts of drinking water safety management.
ABSTRACT
Objective@#To study the effects of atmospheric fine particulate pollution on the lung function of primary school students before and after heating during the winter in Zhengzhou.@*Methods@#In Zhengzhou, two areas with low and high level of PM 2.5 pollution(A and B), were selected as monitoring points from 2016 to 2018. Each monitoring station selected one elementary school within around 1 km and used a cluster random sampling method to extract students from grades 3 to 5 as the research subjects. Lung function tests were conducted before and after heating in winter, and mass concentration of PM 2.5 were recorded daily and compared to those recorded one month prior.@*Results@#The average daily mass concentration of PM 2.5 were 74 μg/m 3 and 92 μg/m 3 in the light pollution monitoring points A and the heavy pollution monitoring points B, which exceeded the standard for 97 and 126 days, respectively. The FVC and FEV1.0 indexes for the first test of male students before heating were higher than those for the second test from 2016-2018 (P<0.05). Except in 2016,the FVC and FEV1.0 indexes for the first test of female students were also higher than those for the second test (P<0.05). After stratified by sex,multivariate linear regression showed that PM 2.5 was associated with lung function as measured by the FEV1.0, PEF, FEF25 and FEF75 values of the students were negatively correlated (B=-0.13--0.07,-0.13--0.08,P<0.05).@*Conclusion@#Fine particulate air pollution before and after heating during the winter in Zhengzhou had different effects on the lung function of primary school students. Therefore, it is necessary to strengthen the respiratory health protection of primary school students in winter to protect their health.
ABSTRACT
Systemic therapy is usually the main treatment for patients with stageⅣbreast cancer at diagnosis. Surgical resection of the primary tumor is typically conducted for palliative reasons, and whether such treatment can benefit patients' survival outcome re-mains unclear. In our clinical practice, proper timing and indications for surgery of the primary tumor, as well as an appropriate surgi-cal technique, may increase the success of local treatment for stageⅣbreast cancer. This article reviews available literature and dis-cusses the role of surgical resection in the treatment of stageⅣbreast cancer at initial presentation.