ABSTRACT
Objective To further understand and master the distribution and influencing factors of water iodine in Jiangsu Province.Methods From 2012 to 2014,half of the water plants in rural centralized water supply monitoring plants in 63 counties (cities,districts) of Jiangsu Province were selected as survey sites,and the types of monitoring,types of water plants,types of water sources,self-inspection ability,disinfection situation,water treatment methods were investigated and analyzed.One sample of peripheral water was collected from each survey site to determine the water iodine content.Results From 2012-2014,there were 938 samples of river water were monitored,and the median water iodine was 5.9 μg/L.There were 57 samples of lake water were monitored,the median water iodine was 6.8 μg/L.There were 228 samples of reservoir water were monitored,and the median water iodine was 7.1 μg/L.There were 43 samples of gully pond water were monitored,and the median water iodine was 6.9 μg/L.There were 5 474 samples of deep well water were monitored,and the median water iodine was 28.2 μg/L.There were 162 samples of shallow well water were monitored,and the median water iodine was 30.9 μg/L.There was a statistically significant difference in the median iodine content of water samples from different water sources (x2 =844.9,P ＜ 0.05).The differences of median iodine of lake water,reservoir water,gully pond water,deep well water and shallow well water among different monitoring types were significant (x2 =9.6,6.3,9.7,121.2,38.1,P ＜ 0.05).The differences of median iodine of river water,reservoir water,deep well water and shallow well water among different types of water plants were significant (x2 =109.5,39.0,153.3,7.6,P ＜ 0.05).The iodine contents of fiver water,lake water,deep well water and shallow well water had significant difference in selfinspection ability of different water plants (x2 =62.5,5.1,29.9,10.1,P ＜ 0.05).The iodine content of reservoir water,deep well water and shallow well water were significandy different in different disinfection situation (x2 =12.1,12.4,35.7,P ＜ 0.05).The medians iodine of river water,reservoir water,deep well water and shallow well water had significant difference in different water treatment methods (x2 =9.5,21.2,102.4,46.9,P ＜ 0.05).Conclusions The water iodine contents of water samples in different types of water sources in rural area of Jiangsu Province are different.The level of water iodine is affected by factors such as monitoring type,type of water plant,self-inspection ability,disinfection situation and water treatment method.
ABSTRACT
Fine particles,less than 2.5 micrometer in diameter (PM2.5),are the main components of inhalable particles.Because of their relatively small size and large surface area,PM2.5 can absorb and retain chemicals,bacteria,viruses and other toxic substances,penetrate deeply into the respiratory tract and easily reach the alveolar ducts,exerting adverse effects on the lungs.PM2.5 can also be absorbed into the bloodstream through alveolar capillaries,causing serious damage to human health.The biological effects produced by PM2.5 are frequently attributed to the oxidative stress induced by intracellular reactive oxygen species alterations and abnormal release of inflammatory mediators closely involved in the development of lung diseases.This review discusses the research advances in relationships between PM2.5 exposure and inflammatory responses and oxidative stress based on experimental researches,in vivo and in vitro studies.Recent epidemiologic investigations have shown associations between increased incidence of respiratory diseases and lung cancer from exposure to low levels of various forms of respirable fibers and particulate matter.In vivo experiments have disclosed the association between PM2.5 exposure and the exacerbation of asthma,bronchitis,chronic obstructive pulmonary disease,and other lung damages.Cell damage mechanisms mainly include alterations of cell signaling pathways,DNA damage,immune injury,autophagy and apoptosis.