Summertime — Is The Living So Easy?

20 July, 2009

by Dr. Peter deFur

Warm weather and vacations find many of us on the water, in the mountains, working in the yard, tending gardens, getting more outside time and maybe doing some recreation. During the summer months, I cannot help but give a thought to the state of the outside places and especially the waters where we seem to spend more time. I know that I tend to gravitate to the water in summer, whether the ocean, my favorite river, or a lake. Unfortunately, many of our outside recreational spots and activities are not as well off as they have been or should be, and I’m afraid our nations waters are particularly so.

Too many of the projects on which I work involve waterways with contamination that makes the fish either unsafe to eat at all, or not safe for unlimited consumption. Fish around the country are routinely contaminated with methyl mercury and PCBs (polychlorinated biphenyls) – catfish, carp and the big predators are often the most contaminated. By now everyone should have some idea that tuna, grouper and wild catfish have too much mercury. Nevertheless, so many of the local rivers and lakes are plagued with a legacy of contamination that remains in the sediments and gets into the fish. These contamination problems require attention sooner rather than later. We’ve waited long enough in Virginia where fish consumption advisories have been in place on the James River for more than 30 years!

The Chesapeake Bay Foundation recently released a report on how polluted waters can affect people’s health. The report is not a comprehensive evaluation or health assessment. Rather, CBF has described several ways in which water pollution results in health threats. Some chemicals, like PCBs and mercury, are taken up by fish and shellfish, making them not safe for consumption.

Excess farm and lawn chemicals will promote the growth of all sorts of algae, changing water conditions if this growth is not controlled. What happens next is a cascade of events that results on foul waters that no longer support a normal assortment of plants and animals. Too much algae is often not able to continue growing and begins to die off, decomposing at the bottom of the river, bay or lake. Decomposing material requires oxygen that is pulled out of the water and carbon dioxide is released. As this process continues, waters are stripped of oxygen and loaded with carbon dioxide that causes the waters to become more acidic. These conditions have become well known in the Gulf of Mexico and the Chesapeake Bay, but are now common in all bays and coastal waters. Such low oxygen conditions are favorable for harmful algae and bacteria, some of which affect fish, oysters and clams, others affect people.

Another type of water pollution problem results from failing septic systems or city sewer systems that are overloaded in heavy thunderstorms. Both situations add to our waters harmful bacteria, excess nutrients and maybe toxic chemicals. Too many rivers and beaches are closed after rainstorms because people might be sickened from the bacteria in the water.

Other bacteria and viruses affect human health more dramatically, causing serious infections or intestinal disease. These micro-organisms grow better in polluted waters that have heavy loads of agricultural and lawn chemicals and not enough oxygen. The CBF report describes a number of cases of these health threats in the Bay area.

What’s to be done about these polluted waters? First off, we can all stop applying lawn fertilizers in the spring and summer months when most of the chemicals wind up in the waters, and not in the plants. Installing rain barrels and rain gardens will also slow the flush of rainwater to the rivers. Clean up after your pets, especially from the streets. Pet poop is as big a problem as broken sewer systems. Keep your septic system working properly and have it inspected by the local health department to be sure there are no problems. Support the efforts of state and local governments to clean up waters contaminated with toxic chemicals.

As far as toxic chemicals in fish, I follow the practice of eating farm-raised (never wild) catfish (and tilapia), wild-caught (never farm-raised) salmon, and local fish and shellfish that I know are free of toxic chemicals. I heed the recommendations to restrict my intake of some fish and not eat any fish from some rivers (unfortunately, my local James River is such a one). Fresh fish is a favorite food, so I am doing my part to restore our fisheries.

The Chesapeake Bay Foundation’s report, Bad Water 2009: The Impact on Human Health in the Chesapeake Bay Region, can be found at www.cbf.org.