View clinical trials related to Arsenic Exposure.
Filter by:In recent years, returning genetic results to research participants has become a topic of debate, with a growing consensus that researchers should offer to return incidental findings and research results to participants. Currently, the research and debates surrounding return of results (ROR) have primarily taken place in high-income countries. Less attention has been paid to ROR in lower-resource countries. However, research participants in these settings may have additional threats, barriers, and/or competing interests that reduce the benefit or relevance of receiving genetic results. Arsenic is a toxic metal. Exposure to arsenic increases a person's risk for cancer, especially in the lung, kidney, bladder and skin. Many people in Bangladesh are exposed to elevated environmental levels of arsenic through naturally contaminated drinking water. People who metabolize arsenic (remove it from their body) slower compared to people who metabolize arsenic more efficiently are at higher risk for arsenic toxicities (e.g. cancer). The investigators have designed a study in which they plan to enroll individuals who have had consistently high urine As levels (≥200 µg/g creatinine) based on 15-20 years of follow-up data. The treatment and control groups will be selected based on genotype (i.e. inefficient and efficient As metabolizers, respectively), allowing for the selection of the groups to be quasi-random (based on inherited genotypes). A standard informational intervention will be provided to both the treatment and controls groups, reminding them of the effects of As exposure and strategies to reduce their exposure. The research question is whether the treatment group will, have a larger decrease in urine arsenic levels compared to the control group, indicating that the ROR intervention caused a change in water-seeking behavior leading to lower arsenic exposure.
The main goals of this study are to evaluate whether supplementation with folate and vitamin B12 to 8 to 10 year old children, in conjunction with reduction in arsenic exposure, can increase arsenic methylation and lower blood arsenic and blood monomethyl arsenic (as previously observed in adults). The investigators will also explore whether folate and B12 can mitigate arsenic-related decrements in cognitive abilities.
Context: Approximately 100 million people throughout the world consume water contaminated with arsenic at levels above carcinogenic thresholds, including 40 million in Bangladesh alone, with up to one-fourth of deaths attributed to arsenic exposure in the worst-affected regions. There are no proven therapies for treating chronic arsenic toxicity or for preventing arsenical cancers. Selenium has been known to counter arsenic toxicity in a variety of animal models. The investigators have recently shown in animals and humans that this effect is mediated by the formation of [(GS)2AsSe]- , the seleno-bis(S-glutathionyl) arsinium ion, which is then rapidly excreted via the hepatobiliary system. Concurrently, two Phase II studies in China and Bangladesh have suggested clinical benefit to selenium supplementation in arsenicosis patients. Objective: To assess whether daily selenium supplementation counters arsenic toxicity in patients exposed to drinking water arsenic. If proven effective, selenium supplementation might be safely and cost-effectively implemented in the worst-affected localities.