Superfund Research Program

Exposomics and Arsenic Epidemiology

Project Leader: Craig Murray Steinmaus
Co-Investigators: Martyn T. Smith, Allan H. Smith
Grant Number: P42ES004705
Funding Period: 1995-2022

Project-Specific Links

Final Progress Reports

Year:   2016  2010  2005 

Dr. Smith and his research team are now in the fifth year of their NIEHS Superfund program renewal focusing on the respiratory and early life effects of drinking water arsenic. During the last year, they found further evidence that some of the most serious consequences from exposure to arsenic in drinking water involve the lung, the reproductive system, and health impacts on children. The following paragraphs list some of the researchers’ key findings.

Their work in West Bengal includes the following: 1. They identified lung function deficits in men consuming high concentrations of arsenic in drinking water. These impacts were so strong, they exceeded those due to smoking (Am J Epidemiol 2005 Sep;162(6):533-41). These data are currently being used to evaluate dose-response relationships and susceptibility time-windows. 2. They used CT scans to show that bronchiectasis is greatly increased in subjects with arsenic-caused skin lesions (Epidemiology 2005 Nov; 16(6);760-5). 3. They identified increased rates of stillbirth in women with arsenic exposure (Am J Epidemiol, in press).

The research team’s work in Northern Chile, Argentina, and the US includes the following: 1. They have confirmed that mortality rates of lung cancer and bronchiectasis in subjects exposed to drinking water arsenic in utero or as young children are very high (SMRs: Lung cancer = 6.1, p < 0.001; Bronchiectasis = 46.2, p < 0.001). Because these findings are based on ecological data, they are currently gathering medical records on all bronchiectasis deaths in order to confirm diagnosis and residence in arsenic-exposed areas. 2. They performed two pilot studies (43 subjects in Chile and the US) of their new method for identifying MMA3, a highly toxic, but highly unstable, arsenic metabolite. 3. In a study of 175 Argentina and 87 US subjects, the researchers found that those who metabolize arsenic poorly have greater risks of bladder cancer than others (accepted, J Occup Environ Med). 4. In 175 Argentina subjects, researchers found that genetic polymorphisms in GSTM1 and MTHFR are associated with inter-individual differences in arsenic metabolism. 5. In a project involving 130 water sources in Nevada, they have found that two arsenic field test kits can be highly accurate compared to laboratory measurements (R = 0.97, p<0.001). 6. The researchers are in the final stages of data collection in their Argentina lung cancer case-control study and are currently doing planning work for a lung cancer case-control study of early life arsenic exposure in Chile.

They are continuing to explore the use of various biomarkers to explore arsenic exposure, toxicity, childhood exposure, and other susceptibility factors. For example, DNA is being extracted from lung tumors obtained in the team’s lung cancer study in Argentina and they are exploring genetic susceptibility in the highly arsenic-exposed population in India, taking advantage of new methods to study the human genome. Each advance in knowledge of arsenic health effects has led to further important questions for research including identifying important susceptible subgroups such as children and helping to determine why humans are 100-1000 times more susceptible to inorganic arsenic than experimental animals.