The Rising Tide of Illness: Global Warming and the Threat of Waterborne Diseases

Water is something we often take for granted as we watch it come out of the tap and into our glass, or enjoy a dip in a cool lake in summer. Water is a health-sustaining necessity, and abundant clean water has long been considered one of America's greatest resources. But what most people don't know is that right here in the U.S., including estimates of cases that go unreported, contaminated water could be causing as many as 33 million gastrointestinal illnesses each year. In 2005-2006, the Centers for Disease Control and Prevention (CDC) reported 28 outbreaks related to drinking water and 78 outbreaks from recreational water use, resulting in over 5,000 reported illnesses and 7 deaths.

A new NRDC factsheet describes how global warming can increase the risk of more frequent and more widespread waterborne illnesses, as temperatures continue to rise, droughts occur with more frequency, and more frequent severe rainfall events occur that can wash disease-causing pathogens into surface and drinking water supplies. These disease-causing pathogens include parasites like cryptosporidium and giardia; bacteria like salmonella and E.coli; and viral hepatitis A. A 1993 outbreak of crypytosporidiosis in Milwaukee sickened over 400,000 people and resulted in 69 deaths when an filter system failed in one of two municipal water treatment plants after the heaviest rainfall in 50 years in nearby watersheds.

And what could climate change do to waterborne disease risks? One study in the Great Lakes projects a possible 50% to 120% rise in the frequency of disease-causing flood events by the end of this century, as temperatures rise and heavy rainfalls increase.

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Today is Blog Action Day, the largest single social action event on the web; more than 6,900 bloggers have signed up to write about global warming. NRDC is a partner of today's online event. We're involved in ongoing research, outreach, and advocacy on global warming and health.

Just last month in Georgia, massive flooding after extreme rainfall events sent raw sewage pouring into the Chattahoochee River near Atlanta, which "provides drinking water for more than 3.5 million people, including 70% of the people in metro Atlanta" according to an NPR story. The river was "chock-full of E.coli" at levels 42 times above the safe level, according to the Atlanta Journal-Constitution, and flooding was estimated to cost more than $250 million in property damage - not including the health costs of illnesses and at least nine deaths.

Early October saw devastating flooding in India that killed at least 350 people, left 1.5 million homeless, and 5 million without food. Some at the Red Cross Red Crescent Climate Centre noted that sudden swings from drought periods to flooding in the region is consistent with projections of the kinds of extreme weather events that climate change can bring.

There are some positive steps we can take to both reduce global warming pollution and adapt to climate change. NRDC signed a letter October 14th, 2009 along with 23 other environmental, science and public health groups, "in support of legislative action to address the critical climate challenge we face" -- and specifically the public health adaptation language and some new funding provisions in the Clean Energy Jobs and American Power Act (S.1733). The letter was sent to Senators on Capitol Hill who are discussing the Clean Energy Jobs and American Power Act.

We are at a critical point in history. We have the tools to help ourselves prepare for climate change -- what international physicians are calling "the biggest global health threat of the 21st century." To help prevent increasing occurrences of water-related illnesses:

We need to urge our leaders to take the kind of decisive action that will reduce global warming pollution, protect human and ecosystem health, and preserve the safety of our drinking water supply for our kids' future, too.