The data, Carson said, dates to before there was any widespread intervention to mitigate the problem such as painting the most unsafe well taps red. On the other hand, since the data dates back to 2000, Bangladeshis have had another decade in which to get sick. Carson is currently working on estimating the magnitude of the most recent effects.
The study's approach, Carson said, is a methodological advance that could potentially help many other public health efforts.
"We show that in some cases it is possible to use a simple labor survey to pick up widespread health problems, if you have a good way to estimate exposure," he said. "To do this in the standard public-health ways is time-consuming and expensive."
The novel method would not be a substitute for gathering blood, urine or hair samples, of course, he cautioned, but it could be a complement. It might be applied to a slew of low-level airborne and waterborne diseases in developing countries, helping epidemiologists get a big-picture view of the magnitude of a problem as well as its geographic scope. Carson notes that this method could be applied to air pollution in developing countries, for example, using simple pollution monitoring measures from which you can infer what people are exposed to.
Bangladesh is most severely affection by arsenic pollution of its groundwater. But it is a worldwide problem, with impacts in the West Bengal part of India and parts of Taiwan, Thailand, Vietnam, Myanmar, Cambodia, China, Argentina and Chile. There are problems in some areas of the United States, too.
In Bangladesh, ironically, the problem was created by a well-meaning attempt to alleviate diseases, those caused by waterborne pathogens in surface water. Encouraged by international aid agencies, Bangladesh installed millions of tube wells throughout the country about 30 years ago to replace surface water as the primary source of drink. At first, Carson said, as
|Contact: Inga Kiderra|
University of California - San Diego