Characteristics and Health Effects of Arsenic Exposure in Bangladesh

Abstract

Arsenic is a potent environmental pollutant and a well-established human carcinogen. Contaminated groundwater is the main source of arsenic exposure in many countries, including Bangladesh. Rural people in Bangladesh depend almost entirely on hand-pumped tube well water, which has been heavily contaminated with arsenic. Considering the country's 125.5 million population in 1999, it has been estimated that more than half of the total population has been exposed to arsenic through drinking water resulting in a serious public health concern and a socioeconomic burden to the country. Chronic arsenic exposure is associated with skin lesions, cancer, cardiovascular diseases (CVDs), and other chronic diseases such as diabetes and respiratory dysfunctions. We conducted a series of epidemiological studies to quantitatively evaluate the arsenic-related organ and vascular dysfunctions and to explore the underlying mechanisms of arsenic-induced chronic diseases. We used three arsenic exposure metrics: drinking water arsenic concentrations as an external exposure marker and hair and nail arsenic concentrations as internal exposure markers reflecting long-term arsenic exposure at the individual level. Using these multiple arsenic exposure metrics (which showed significant correlations with each other), we investigated the dose-response relationships of these exposure markers with a variety of blood biochemical markers for organ dysfunctions, atherosclerosis, and cancer among study subjects recruited from arsenic-endemic and non-endemic areas in Bangladesh. Our results demonstrate that chronic arsenic exposure can induce pro-inflammatory, pro-oxidative and pro-angiogenic microenvironments in the vascular system, leading to the development of CVDs as well as cancer. Further studies are required to elucidate the effects of neonatal and early-life arsenic exposure on later life in Bangladesh, where over 30% of the population is under 15 years of age.