Friday, August 31, 2007

Arsenic in drinking water seen as threat

Yahoo! News
Arsenic in drinking water seen as threat

Arsenic in drinking water is a global threat to health, affecting more than 70 countries and 137 million people, according to new research.

Large numbers of people are unknowingly exposed to unsafe levels of arsenic in their drinking water, said Peter Ravenscroft, of the Department of Geography at the University of Cambridge. He made his remarks at an annual conference of the Royal Geographical Society in London on Wednesday.

The country worst affected is Bangladesh, where hundreds of thousands of people are likely to die from cancers of the lung, bladder and skin caused by arsenic, the research said.

Arsenic, which is odorless and tasteless, enters water supplies from natural deposits in the Earth or from agricultural and industrial practices.

World Health Organization guidelines set a safe limit of 10 parts per billion of arsenic in water supplies, but 137 million people drink water with levels higher than that — and 57 million drink water with a level of more than 50 ppb, according to the research.

Arsenic poses long-term health risks "exceeding every other potential water contaminant," according to research presented by Allan Smith of the University of California, Berkeley, an adviser to the WHO on arsenic.

"Most countries have some water sources with dangerous levels of arsenic, but only now are we beginning to recognize the magnitude of the problem," Smith said. "It is the most dangerous contaminant of drinking water in terms of long-term health risks, and we must test all water sources worldwide as soon as possible."

Speakers at the conference predicted that new arsenic pollution would occur in parts of southeast and southwest Asia, the western parts of South and Central America, and some areas in Africa.

Arsenic has been found in water in the north of England, the Midlands and mid-Wales. But Ravenscroft said there was no major health risk in Britain and that tests carried out by water companies meant that public water supplies in this country were still safe to drink.