Arsenic and child respiratory health in Bangladesh

描述(由申请人提供)：对于摄入饮用水中的无机砷对健康的长期影响，肺部是一个令人惊讶的重要目标，但儿童时期接触无机砷的影响在很大程度上是未知的。儿童可能特别容易受到影响，因为肺部的发育一直持续到儿童时期。在智利，我们发现，儿童时期接触饮用水中砷的人，成年后患肺癌和慢性呼吸道疾病死亡的风险增加10倍。在印度西孟加拉邦，我们发现，由砷引起的皮肤损害和高砷饮用水暴露的成年人损害了肺功能，增加了慢性呼吸道疾病的发病率。然而，到目前为止，儿童摄入砷对肺功能和呼吸健康的影响还没有研究。这个应用程序利用了这样一个事实，即我们在孟加拉国的合作者已经检查了167,000人的皮肤损害，并测量了他们饮用水中的砷浓度。我们计划对300名6-16岁的儿童进行研究，这些儿童生活在管井水砷浓度大多超过300ug/L的家庭中，其中至少有一名家庭成员发生了与砷相关的皮肤损害。一组未接触砷的儿童将从没有皮肤损害的家庭中挑选出来，其水中的砷含量低于50ug/L。将根据儿童时期所有饮用水来源当前和过去的砷浓度，包括在宫内接触砷，评估肺功能和呼吸道症状，包括慢性咳嗽和呼吸急促。将调查与室内空气污染、饮食和营养状况相关的潜在易感性和相互作用。还将评估由于儿童代谢砷的程度的个体差异而对尿样中发现的剧毒甲基化化合物的易感性差异。这些暴露和未暴露家庭的儿童提供了一个独特的机会，以确定在肺部生长和发育的关键时期暴露于砷的影响。鉴于世界各地大量儿童接触饮用水中的砷，以及这些后果与未来人口发病率和死亡率的相关性，早期接触砷对公共健康的不利影响可能是巨大的。

DESCRIPTION (provided by applicant): The lung is a surprisingly important target for the long term health effects of ingestion of inorganic arsenic in drinking water, but the impact of exposure during childhood is largely unknown. Children are likely to be especially susceptible since the development of the lung continues into childhood. In Chile, we have found that people who were exposed to arsenic in drinking water as children have 10-fold increased risks of lung cancer and chronic respiratory disease mortality when they become adults. In West Bengal, India we have found that adults with arsenic-caused skin lesions and high arsenic drinking water exposures have impaired lung function and increased rates of chronic respiratory disease. To date however, the impact of arsenic ingestion on lung function and respiratory health has not so far been studied in children. This application takes advantage of the fact that our collaborators in Bangladesh have examined 167,000 people for skin lesions and measured the arsenic concentrations in their drinking water. We plan to study 300 children aged 6-16 years living in the families having tube well water arsenic concentration mostly over 300 ug/L, and in which at least one member of the family has developed arsenic-related skin lesions. An unexposed comparison group of 300 children will be selected from families with no skin lesions, and whose water contains less than 50 ug/L. Lung function and respiratory symptoms, including chronic cough and shortness of breath, will be assessed in relation to current and past arsenic concentrations in all sources of drinking water throughout childhood, including in utero exposure. Potential susceptibility and interactions associated with indoor air pollution, diet, and nutritional status, will be investigated. Differences in susceptibility due to individual variability in the degree to which children metabolize arsenic to highly toxic methylated compounds identified in urine samples will also be assessed. The children in these exposed and unexposed families provide a unique opportunity to identify the effects of arsenic exposure during critical time periods of lung growth and development. The public health impact of adverse respiratory effects due to arsenic exposure in early life could be substantial given the large number of children exposed to arsenic in drinking water worldwide and the relevance of these outcomes for future population morbidity and mortality.