Arsenic in drinking water and the prevalence of respiratory effects in West Bengal, India

Background A large population in West Bengal, India has been exposed to nat urally occurring inorganic arsenic through their drinking water. A cross-se ctional survey involving 7683 participants of all ages was conducted in an arsenic-affected region between April 1995 and March 1996. The main focus o f the study was skin keratoses and pigmentation alterations, two characteri stic signs of ingested inorganic arsenic. Strong exposure-response gradient s were found for these skin lesions. The study also collected limited infor mation concerning respiratory system signs and symptoms, which we report he re because increasing evidence suggests that arsenic ingestion also causes pulmonary effects. Methods Participants were clinically examined and interviewed, and the arse nic content in their current primary drinking water source was measured. Th ere were few smokers and analyses were confined to non-smokers (N = 6864 pa rticipants). Results Among both males and females, the prevalence of cough, shortness of breath, and chest sounds (crepitations and/or rhonchi) in the lungs rose w ith increasing arsenic concentrations in drinking water. These respiratory effects were most pronounced in individuals with high arsenic water concent rations who also had skin lesions. Prevalence odds ratio (POR) estimates we re markedly increased for participants with arsenic-induced skin lesions wh o also had high levels of arsenic in their current drinking water source (g reater than or equal to 500 mug/l) compared with individuals who had normal skin and were exposed to low levels of arsenic (<50 <mu>g/l). In participa nts with skin lesions, the age-adjusted FOR estimates for cough were 7.8 fo r females (95% CI:3.1-19.5) and 5.0 for males (95% CI:2.6-9.9); for chest s ounds FOR for females was 9.6 (95% CI:4.0-22.9) and for males 6.9 (95% CI:3 .1-15.0). The FOR for shortness of breath in females was 23.2 (95% CI: 5.8- 92.8) and in males 3.7 (95% CI: 1.3-10.6). Conclusion These results add to evidence that long-term ingestion of inorga nic arsenic can cause respiratory effects.