Arsenic shown to cause diarrhoea and affect lung function

Those exposed to arsenic in Bangladesh may be at higher risk of childhood respiratory tract infection and diarrhoea, suggests a new systematic review by icddr,b.

Arsenic exposure in pregnancy can harm children’s lung function years after birth. Photo: Shumon Ahmed / icddr,b

Reportedly 20 to 40 million people in the country are exposed to arsenic through drinking water or food, the long-term effects of which include skin lesions, cancer of various organs, cardiovascular disease, diabetes and developmental defects, according to the World Health Organization (WHO).

Adding to these well-established effects, the recent review now bolsters existing findings that have been consistent in suggesting links between arsenic exposure and respiratory tract infections or diarrhoea.

“The harmful effects of arsenic are well-known yet many people including pregnant women continue to drink contaminated water,” says Dr Anisur Rahman, head of icddr,b’s Matlab Health Research Centre and author of the review published in Archives of Toxicology.

Water from a hand pump is being tested for the presence of arsenic. Photo: Emdadul Islam Bitu / icddr,b

Dr Rahman feels that the arsenic problem lingered because of the failure to identify an effective strategy to mitigate the problem.  

“Experience from field-level interventions indicated that people once had limited knowledge of arsenic exposure. Despite knowing the risks many wanted continuous water flow which many water filters could not provide. Rainwater harvesting, as an alternative, did not work in many areas and deep tube-well water may contain other elements in high concentrations, harmful to health,” he observes.

Large-scale mitigation efforts had successfully reduced drinking water arsenic in rural Bangladesh, found a recent study conducted with icddr,b. Despite this children still had elevated arsenic exposure through contaminated food. Use of arsenic-contaminated water from shallow pumps for irrigation can introduce arsenic into crops such as rice/paddy, contaminating food supply chains.

Arsenic in staple food such as rice might have the most far reaching effect on a larger population.

Shallow pumps for irrigation can introduce arsenic into crops. Photo: Shumon Ahmed / icddr,b

Recent findings by icddr,b researchers provide further evidence that arsenic exposure affects lung function both in children and adults. Exposure to arsenic-laced drinking water while in the womb can hamper lung function in children for many years after birth, according to the findings published in Environment International.

“In addition, arsenic exposure may also interfere with specific vaccine response in children,” says Dr Rubhana Raqib, senior scientist at icddr,b and author of another icddr,b study published in Environmental Health Perspective.

Dr Muhammad Yunus, an emeritus scientist at icddr,b with extensive experience of conducting arsenic related work, feels that  research has generated a large body of evidence to support a wide range of negative health effects stemming from arsenic exposure.

Skin lesions - a long-term effect of arsenic exposure. Photo: icddr,b

“The adverse health consequences including increased death due to chronic arsenic exposure through drinking water are now well established by high quality scientific research from Bangladesh and other countries,” he says.

“The most important public health action now is the prevention of arsenic exposure,” he insists.

Dr Yunus concludes that research will continue to unearth more adverse effects, but ultimately concerted effort to ensure arsenic-free water for the affected communities is all that is required.

Muhamamd Zahir Hassan Nabil