Non-malignant diseases associated with environmental arsenic exposure in Taiwan, Chile, and Bangladesh

Abstract

Extensive epidemiological studies in Taiwan, Chile, and Bangladesh have shown that chronic arsenic exposure is associated with increased incidence and prevalence of skin lesions, cancers, as well as non-malignant disorders such as hypertension, diabetes mellitus, cardiovascular diseases, and respiratory diseases. However, the underlying mechanisms of how arsenic facilitates vascular disorders and diabetes remained unclear. To understand biochemical mechanisms related to arsenic-induced non-malignant diseases, we have examined the relationships between disease-related blood biomarkers and arsenic exposure levels in the arsenic-contaminated area in the western region of Bangladesh. In this review, we presented a summary of the findings of our studies in Bangladesh and discussed their significances in comparison with epidemiological observations in Taiwan and Chile. We have identified arsenic-induced changes in the biomarkers reflecting oxidative stress, inflammation, dyslipidemia, vasoconstriction, monocyte adhesion, and angiogenesis, all related to promoting atherosclerosis and hypertension. Determinations of glucose intolerance, serum insulin and creatinine, and lean body mass suggested a potential role of arsenic-induced skeletal muscle atrophy and its association with insulin resistance. Respiratory function tests and measurements of serum immunoglobulin E and cytokines showed that arsenic-induced T helper 2 (Th2)-dominant immunomodulation might predispose to developing Th2-high type asthma. Thus, the investigation of disease-related biomarkers allowed us to provide novel insight into biochemical mechanisms of arsenic-associated increases in non-malignant diseases.

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