The earth is one big ecosystem. Think of it as a human body. Every cell, every organ, every system of organs is interdependent. Think of the water in the earth’s rivers as blood in the body’s circulatory system. What happens to the body when infection invades the blood stream? What happens when the body cannot produce enough cells to maintain a sufficient, systemic blood level? The answer, of course, is illness.

Industrialization, urbanization, and global warming have adversely affected the rivers of the world. Pollution and insufficient water levels pose a serious health threat to all life in the surrounding regions. The problem is common to big cities as well as rural areas. The best way to illustrate this point is to cite specific examples.

From approximately 1947 to 1977, the General Electric Company poured an estimated 1.3 million pounds of polychlorinated biphenyls (PCBs) into the Hudson River from manufacturing plants at Hudson Falls and Fort Edward.

The health of area residents is at risk due to the accumulation of PCBs in the human body caused by eating the river’s contaminated fish. Since 1976, high levels of PCBs in fish have led New York State to close various recreational and commercial fisheries and to issue advisories restricting the consumption of fish caught in the Hudson River. PCBs contain carcinogenic substances known to stimulate the growth of cancer cells in humans. Additional adverse health effects include low birth weight, thyroid disease, nervous and immune system disorders. PCBs in the river sediment also affect fish and wildlife.

Runoff in urban and rural areas can easily affect a river’s health, putting local wildlife and human life at risk. Nitrates from fertilizers and pesticides collect in rainwater draining from surrounding land into rivers. These chemicals stimulate the growth of algae, throwing delicate, ecologic relationships out of whack. The result is a clogged, dysfunctional river system.

Runoff from acid rain and rain falling through polluted air is another source of contamination. A recent report states that pollution from urban runoff has become the Potomac River region’s fastest-growing water quality problem, threatening the quality of drinking water for 86 percent of local residents.

Several Abandoned mines located in England and Wales have caused significant pollution in nearby rivers. Dangerous metals such as iron, aluminum, tin, lead, mercury and cadmium from old mine workings contaminate drinking water extracted from regional rivers fed by polluted tributaries.

Phosphorous from detergents in sewage flushed into rivers is another dangerous pollutant. The chemical stays in the system for a long time, threatening plant life by taking up oxygen and poisoning the drinking water of animals and humans alike. The impact of a slow buildup of river pollution in a wide area can be devastating. In the 1950’s, the otter population in England was nearly wiped out by the accumulation of toxic wastes in major rivers throughout the country.

Rising weather temperatures caused by global warming have had a dramatic effect on fresh water levels in rivers around the world. Persistent drought conditions in Australia’s major farming region, the Murray-Darling river basin, threaten the nation’s food supply. The Murray-Darling crosses most of southeastern Australia and is one of the region’s most important river systems. It provides water for growing 40 percent of the nation’s vegetables, fruits, and grains.

Corey Watts, of the Australian Conservation Foundation in Melbourne, told reporters that drought conditions were becoming the norm in the area instead of occurring once every 20 to 25 years.

“We’ve had a string of official reports over the last fortnight painting a pretty grim picture for the climate and the future of our economy and our environment,” Watts said. “So now we’re looking at a future in the next few decades where drought will occur once every two years.”

The 2,000 year-old Yamuna is a river that “fell from heaven,” according to Hindu mythology. The residents of New Delhi worship the river and depend on it for life. Residents tossing coins and sweets into the river, or scattering the ashes of dead relatives from bridges jutting across the waters are a common sight. Unfortunately, the actions of the citizenry and the New Delhi governmental water board do not coincide with this feeling of reverence.

As the Yamuna enters the capital city, its waters are still relatively clean after a 246-mile descent from atop the Himalayas. New Delhi’s public water authority, the Jal Board, extracts 229 million gallons from the river daily for drinking water. As the river leaves the city, residents pour an average 950 gallons of sewage into the Yamuna every day.

As it winds through India’s capital city, the Yamuna transforms into a filthy band of black ink with clumps of raw sewage floating on the surface. Methane gas bubbles to the surface. The river is hardly safe for fish, let alone bathing or drinking water.

A recent government audit condemned the Jal Board for spending 200 million dollars on the construction of sewage treatment plants with minimal results. One of the city’s Pollution Control Board Directors said the situation “has not improved at all because the quantity of sewage is always increasing.” The regular occurrence of power failures adds to the problem.

The above examples are only a tiny representation of the problem. The health of the world’s rivers and their effects on plant, animal, and human life is a complex problem difficult to summarize in one short article. Governmental water management boards worldwide are struggling to deal with the problem now to avoid catastrophic water shortages in the next twenty years. Bold, new initiatives are under consideration along with traditional methods. One point is clear, however. Change in the way we treat the environment, collectively and individually, is essential.

The new movie, “The Day the Earth Stood Still,” explores this theme. The story posits the theory that painful and necessary change can occur when it becomes obvious that doing things the same old way will lead to certain destruction. Certainly, we have reached this point with respect to the environment. Two questions remain. Will we change? Can we change in time to prevent a complete breakdown of the earth’s life sustaining ecosystem?

Sources: Gertner, Jon, “The Future Is Drying Up,” Time Magazine, October 21, 2007; Government of Australia — Waters and Rivers Commission, “Water Facts,” July 1997; Sengupta, Somini, “In Teeming India, Water Crisis Means Dry Pipes and Foul Sludge,” The New York Times, September 26, 2006.