Dear EarthTalk: I've heard that some foods are now being irradiated. Why is this and what are the implications for our health and safety?
— Emily Worden, Monroe, CT
Food irradiation—used to kill bacteria, parasites and insects in food and to retard spoilage—is actually not new. Research began early in the 20th Century and picked up in the 1950s as part of the U.S. government's "Atoms for Peace" effort to find non-wartime uses for nuclear technology. The U.S. Food and Drug Administration (FDA) began approving food irradiation in 1963 to rid wheat and flour of insects, and to control the sprouting of potatoes. It later approved irradiation of spices and seasonings to fight insect infestations, then pork (to prevent trichinosis), poultry (to prevent salmonella and other food-borne bacterial pathogens) and more recently beef, lamb and pork (to kill E. coli).
The U.S. Centers for Disease Control and Prevention and the World Health Organization (WHO) both endorse food irradiation, and over 40 countries have approved its use. WHO calls the practice "sound food-preservation technology
badly needed in a world where food-borne diseases are on the increase."
In recent years a series of highly publicized events led to increased use of irradiation. In 1998, Sara Lee recalled millions of pounds of hot dogs and deli meat after 21 people died in a Listeria outbreak. In 2000, a young Milwaukee girl died after eating watermelon splashed with E. coli at a Sizzler restaurant. The E. coli, which made 600 other people sick, was traced to a Colorado meat plant. In 2002, ConAgra recalled 19 million pounds of E. coli-contaminated beef. There are some 33 million cases of food-related illnesses each year, and 9,000 deaths. Food poisoning caused by E. coli affects up to 20,000 people annually.
The U.S. Food and Drug Administration (FDA) says irradiation is safe, but critics charge otherwise. Irradiation does not make food radioactive, but it can create toxic byproducts and some "unique radiolytic products" that haven't yet been identified or tested, says Dr. John W. Gofman of the University of California at Berkeley. "We know that irradiation causes a host of unnatural and sometimes unidentifiable chemicals to be formed within the irradiated foods," he says. "Our ignorance about these compounds makes it simply a fraud to tell the public "we know" irradiated foods are safe to eat." The Organic Consumers Association (OCA) claims that irradiation saps food's nutritional value, and charges that irradiation deactivates raw food's natural digestive enzymes and encourages fats to turn rancid.
Caroline Smith DeWaal, Director of Food Safety at the Center for Science in the Public Interest (CSPI), says that irradiation's benefits outweigh its risks, but fears irradiation may be seen as a "silver bullet," leading to neglect of effective sanitation measures in the production of food in the first place. Patty Lovera of Public Citizen agrees: "People are getting sick because cattle are crowded into small pens, sleeping in their own waste. Then they move through slaughter so quickly that mistakes cause fecal matter to contaminate the meat." Even the pro-irradiation American Dietetic Association says: "the process is not a replacement for proper food handling practices."
CONTACTS: U.S. Food and Drug Association, (888) 463-6332, www.fda.gov; Organic Consumers Association, (218) 226-4164, www.organicconsumers.org; Center for Science in the Public Interest; (202) 332-9110, www.cspinet.org; Public Citizen, (202) 588-1000, www.citizen.org; American Dietetic Association, (800) 877-1600, www.eatright.org.
Dear EarthTalk: What is the environmental impact of sewage from boats and ships on our waterways?
— Eileen Macaw, Traverse City, MI
There is a clear relationship between the number of boats in a given area and the levels of coliform bacteria in both water and shellfish, reports the San Francisco Estuary Project. High levels of coliform bacteria, which indicate sewage pollution, can spread disease, contaminate shellfish beds and decrease oxygen levels in the water. Studies on swimmers, scuba divers and windsurfers show the effects of contact with bacteria-infested waters, which include nausea, vomiting and diarrhea. Individuals may also become ill by eating shellfish that have consumed human sewage.
Even coral reef communities are affected when high bacterial levels cause an overgrowth of aquatic plants and algae. Dead zones, like the one currently in the Gulf of Mexico, are areas of the ocean starved of oxygen because sewage has spurned robust algae blooms that consume all available oxygen when they die and decompose. Fish and plants can no longer survive in these areas.
According to the Oceans and Coastal Protection Division of the U.S. Environmental Protection Agency (EPA), slow-flowing rivers, lakes, marinas and "other bodies of water with low flushing rates" are particularly susceptible to the havoc brought on by boat sewage. To counter the problem, in 1998, the Federal Clean Water Act allowed states to designate all or portions of their bodies of water as no-discharge zones. These zones help to ensure that public drinking water is not contaminated. Currently, six states have adopted the policy. The act also regulates standards for marine sanitation devices—boat toilets. Such legislation aims to improve the quality of water at recreation sites for both human and aquatic life.
One of the largest waterway polluters is the cruise ship industry, which often dumps raw sewage directly into the sea. According to Jackie Savitz, Pollution Campaign Director and Senior Scientist for the Washington, D.C.-based nonprofit organization, Oceana, the cruise ship industry alone discharges tens of thousands of pounds of sewage a day into some of the most pristine parts of the ocean. The extent of the effect of such pollution depends on where you are, she explains. In more sensitive ecosystems, such as in Alaska and Hawaii, cruise ship sewage is a huge percentage of the water pollution problem, where other sources, such as sewer overflows, may have more of an impact on water quality in places such as New York. Discharge into the ocean by cruise ships is not covered under the Clean Water Act, but states can take action. Alaska was the first to pass a law requiring tougher standards for cruise ships, says Stavitz.
Oceana recently targeted Royal Caribbean to pressure them to clean up their dumping practices. After an 11-month campaign, during which some 90,000 people signed a pledge to not sail with Royal Caribbean until it took action, the company agreed to adopt sophisticated wastewater treatment technology to treat sewage on board, and is now installing systems throughout its entire fleet.
CONTACTS: San Francisco Estuary Project, (510) 622-2465, www.abag.ca.gov/bayarea/sfep; U.S. Environmental Protection Agency's Oceans and Coastal Protection Division, (202) 260-1952, www.epa.gov/owow/oceans; Oceana, (202) 833-3900, www.stopcruisepollution.com.