The Global Reach of Water Pollution
by Devra Lee Davis, PhD, MPH, Director, Center for Environmental Oncology of UPCI, and Donald S. Burke, MD, Dean, Graduate School of Public Health (GSPH), University of Pittsburgh; Associate Vice Chancellor for Global Health
For centuries, people have understood that contaminated water can kill humans, fish and wildlife. Modern techniques to treat water save lives by freeing water of bacteria and viruses. But, recent research confirms that water polluted by industrial sources also can increase the health risks of humans and wildlife living thousands of miles away and that some treatment technologies can increase the risk of cancer and other diseases. Two out of every five persons on this planet—more than 2.6 billion people—do not have access to basic sanitation, and more than one billion do not have safe water to drink. As a consequence, in many rapidly developing countries, thousands die every day from diarrhea and other water-, sanitation- and hygiene-related diseases.
Cancer today is the leading cause of death throughout China. While smoking remains an important cause of cancer worldwide, tobacco does not account for growing rates of the disease in many areas of China. Recent official reports from China confirm that in addition to the well-understood immediate biological threats to public health from lack of clean water, extraordinary rates of cancer are now occurring in people living adjacent to industrially-central riverbeds. Lately, the Chinese government has admitted that cancers in people living along some of its heavily polluted rivers and streams in Huangmengying in the Huai River basin follow the steady flow of heavy metals, leather tanning, paper and pulp mills, and other uncontrolled pollutants that render half of its waters undrinkable.
In one such community, in the small village of Shangba in southern China's Guangdong Province, 4 out of every 5 deaths are due to cancer. Reports from a Guangdong research institute determined that lead concentrations in local wells are at least 15 times greater than federal standards allow—0.15 parts per million (PPM).
The official government newspaper—there are no others—reported on May 22, 2007, "Many chemical and industrial enterprises are built along rivers so that they can dump the waste into water easily," Chen Zhizhou, a health expert with the cancer research institute affiliated with the Chinese Academy of Medical Sciences, told the newspaper. "Excessive use of fertilizers and pesticides also pollute underground water. The contaminated water has directly affected soil, crops and food." (p. 354, The Secret History of the War on Cancer.)
One of us (DB, Jonas Salk Chair in Global Health and Dean at GSPH), recently led a trip to Wuhan, China that confirmed the challenging problems of protecting public health in the face of rapid industrial growth. A city of close to ten million, Wuhan, like Pittsburgh, sits at the point of two rivers, the Yangtze and the Han. It is a major inland port and center of commerce for all of central China. Known in the summer as one of China's urban "furnaces" for its searing heat, this past winter, Wuhan was hit with one of the coldest periods in modern times. Lacking the infrastructure to support such big changes in weather, thousands are believed to have perished during this unexpected cold snap.
Polar Bears: Heading Toward Extinction?
The polar bear, found on the arctic coasts and islands of the five countries around the North Pole——the United States (Alaska), Canada, Denmark (Greenland), Norway and Russia——is the only species that still lives throughout its original range, with an estimated 20,000 remaining in the wild.
Polar bears are at risk of extinction for two reasons: global warming, including the diminishing coverage of sea-ice, is causing catastrophic environmental changes in the Arctic. As the US Fish and Wildlife Service–Alaska explains on its website, "…polar bears are almost completely dependent upon sea ice for their sustenance. Any significant changes in… sea ice will have effects on the number and behavior of these animals and their prey."
Additionally, even in the seemingly pristine Arctic environment, the spread of hormone-disrupting, cancer-causing flame retardant and other chemicals in the waters also threatens the polar ice edge ecosystem, including walrus, seals and penguins, as well as polar bears.
Several groups have proposed listing the polar bear as a threatened species under the Endangered Species Act, but the U.S. government has not yet done so.
Such a listing would bar U.S. government agencies from any activity that would jeopardize the bears, and could potentially compel US industries to curb their output of carbon dioxide and other warming greenhouse gases.
The GSPH at the University of Pittsburgh has launched a number of programs with Wuhan colleagues to identify serious challenges to public health, determine their remedies, and evaluate their public health consequences. The essential impact of the environment on human health has become an undeniable fact to the leaders of China. While gross domestic product per capita has grown nearly 10 percent a year for the past decade, this is matched by the estimated damages such growth has caused for the environment. China's environmental leaders understand that they face a major turning point.
For more than two decades, Pittsburgh and Wuhan have been "sister cities," exchanging visits of local government leaders on several occasions. Appreciating the need to develop policies to redress the serious environmental challenges of modernization, this past year, with support from the Chinese government, the two formed a Confucius Institute, with the goal of advancing research and environmental health. Two recent high-level developments in China should favor the creation of new efforts. On November 21, 2007, the Chinese government launched its first national environmental health action plan for the Years 2007-2015 to provide basic principles, goals, and action strategies to be implemented nationally. The plan calls for the establishment of surveillance networks, interagency cooperation, and collaborative international research. In addition, this past year, the Chinese government announced that a cluster of four cities in central China, one of them Wuhan, has been designated a national experimental zone to develop and evaluate new environmentally friendly programs. The National Development and Reform Commission has directed these cities to "as quickly as possible form systems and mechanisms beneficial to energy saving and environmental and ecological protection."
One stunning signal of the global reach of pollution comes from recent studies conducted for the United Nations on polar bears. At the top of the Arctic food chain, polar bears are showing up in the Arctic with flame-retardants and other toxic pollutants in their fat that may well have originated in Wuhan and other areas of China's industrial heartland, or those of many other rapidly growing urban centers throughout the world today. The bears do not work in factories, but because they are at the top of the food chain, they eat smaller fatty fish and mammals that have absorbed fat-loving pollutants. The fatter, older, and larger the animal is, the greater its capasity to store and accumulate these pollutants. As a result, the polar bears are experiencing serious health problems, as are many Arctic mammals such as walrus, seals, and penguins (See sidebar). The last polar bear survey conducted by Norwegian scientists found that one in a hundred was a hermaphrodite, and levels of some industrial contaminants in their fat would qualify them for burial in a hazardous waste site.
Efforts to reduce pollution in China are understood by authorities in that country and experts in Pittsburgh as having profound local and global impacts. Cleaning up bodies of water is a priority, but it's important to note that modern water treatment, like chlorination, can also create toxic byproducts that need to be controlled. The benefits of improving our treatment of drinking water and reducing industrial pollution of lakes, rivers and oceans will range widely, reducing both immediate and long term health threats to those who live nearby and also lessening dangers to the majestic polar bears thousands of miles away.
