05/16/2011 10:50 pm ET | Updated Jul 16, 2011

Save the Bay, Save Your Life

The Maryland Senate is considering new restrictions on lawn fertilizers, a measure already approved by the House. As a doctor, let me remind our friends in Annapolis that we would get a lot more benefit for the Bay--and for our own health--if we would clean up Maryland agriculture.

Here's the problem. Maryland producers raise and slaughter an enormous number of chickens--close to a million per day. And it takes almost three pounds of feed grain to produce a pound of chicken. That's right--it's not you and I who are eating the 60 million bushels of corn and 20 million bushels of soybeans raised in Maryland every year. Most of it is fed to chickens and other animals. As rain water trickles from agricultural fields into rivers and streams, it picks up traces of the fertilizers producers have applied. As nitrogen and phosphorus wash into streams, they stimulate a massive overgrowth of algae, which uses up oxygen from the water--oxygen that fish and other aquatic life need. Without oxygen, they die.

A dead zone was found in the Chesapeake Bay in the 1970s. Many other dead zones were later identified where agricultural runoff collects. Below Louisiana and Texas in the Gulf of Mexico, there is a dead zone as big as New Jersey--more than 8,000 square miles. It is there because the Mississippi River drains 40 percent of the U.S. surface, flushing its load of fertilizer into the discolored, malodorous Porta-Potty we call the Gulf of Mexico.

Luckily, toilets can be cleaned, and a dead zone can be brought back to life. The Black Sea, between Turkey and Ukraine, once held the biggest dead zone in the world. But after the collapse of the Soviet Union and its economic programs in 1991, fertilizers became too costly to use. The devitalized area gradually regained its health and fish eventually returned.

The problem is not just fertilizer, though. Poultry manure--high in nitrogen and phosphorus and produced in enormous quantities (650 million pounds per year in Maryland)--also pollutes rivers and disrupts ecosystems. Innovative chicken farmers have found a way to get rid of some of it: Believe it or not, they feed chicken manure to cattle. As long as cattle feed is no more than about fifteen percent manure, cows do not balk at it.

Here is my prescription. Maryland legislators--and all the state's citizens--can kickstart the health of the Bay by trying out a plant-based diet. If we eat grains, beans, vegetables, and fruits directly, instead of using grains to fatten animals, we could cut down on land use and pollution. Our leaders in Annapolis should be role models for environmentally conscious eating.

There is, of course, another advantage to a plant-based diet. Two-thirds of Maryland residents are overweight, and 26 percent are obese, according to the latest statistics from the Centers for Disease Control and Prevention. A plant-based diet dramatically cuts our risk of obesity, diabetes, hypertension, heart disease, and certain cancers, too. That means it will also cut our collective health care bill.

There's a lot to like in a plant-based diet. Now, if it sounds like a tall order, I suggest doing it for just three weeks, which is more than enough time to see health benefits. The payoff is potentially huge: A cleaner Bay, cleaner arteries, and a clear pathway to health for the next generation of Maryland citizens.

Neal Barnard, M.D., is a nutrition researcher and president of the Physicians Committee for Responsible Medicine.