According to research published online in the American Journal of Agricultural Economics, exposure to arsenic in rural Bangladesh is poisonous to the nation’s economy and has reduced the labor supply by 8 percent.
“This is a very large effect,” said lead author Richard Carson, professor of economics at the University of California, San Diego, “larger than the increase in unemployment in the United States from the Great Recession.”
The exposure also has altered work arrangements, changing how labor is allocated within a household. Bangladesh is a poor country and many of its citizens have limited access to health care and health insurance, researchers pointed out. Most families have to fend for themselves. As a result, women older than 45 are working fewer hours outside the home while men aged 25 to 65 are working more.
“Essentially, what we think is happening,” Carson said, “is that Grandma stays home to take care of the sick people while all the able-bodied men are working longer hours to compensate.”
The arsenic problem in Bangladesh dates to the 1970s, when shallow groundwater wells were installed throughout the country, unwittingly tapping into naturally occurring arsenic in the ground. The present study uses a novel method that, according to Carson and his coauthors, could be applied to discovering the effects of other environmental pollutants in developing nations, sooner.
Previous studies, on what some say is the largest manmade environmental health disaster in the world, worse than Chernobyl, focused on the long-term health consequences of arsenic poisoning: cancers, heart problems, diabetes and a range of skin conditions, including the growth of painful nodules on the palms of hands and soles of feet.
But these deadly and debilitating effects all take a long time to manifest. The latency period for cancers linked to arsenic is estimated to be about 20 or more years. Of the 57 million rural Bangladeshis who have been exposed to unsafe levels of arsenic, said Carson, only a small fraction will ever get that sick. The initial (and presumably more common) effects, on the other hand, include feelings of general lethargy and sores on hands and feet, along with headaches and confusion – effects that may not show up as reported health conditions but could affect the labor supply.
Carson and colleagues looked at the relationship between arsenic exposure and hours worked by households as reported in the Bangladesh government’s standard survey used for this purpose. Their sample included 4,259 rural households from the Household Income and Expenditure Survey carried out by the Bangladesh Bureau of Statistics in 2000 and was matched with data on arsenic contamination from a large-scale study done by the British Geological Survey.
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 currently is working on estimating the magnitude of the most recent effects.
“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 method would not be a substitute for gathering blood, urine or hair samples, 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 added 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, the problem was created by a well-meaning attempt to alleviate diseases 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 diarrhea and other gastrointestinal diseases from contaminated surface water cleared up quickly, it seemed that the well-water solution had been successful. It was not until 1993 that the country’s chronic arsenic poisoning was diagnosed. The massive scale of the problem was not fully known until around 2000.