(a) Always wash your hands carefully with soap and water when returning home from outside and before handling food. Hand washing is a very effective way to remove pathogens. Regular hand washing also protects against catching colds or flu from other people.

(b) Do not drink tap water that has not been properly filtered or kept at a rolling boil for at least five minutes. Chlorination does not kill the cyst forms of parasites like Giardia or Cryptosporidium. Use water filters that are certified by the National Sanitation Foundation (NSF), an independent non profit organization, under their Standard 53 for "cyst removal". No water filter practical for home use will remove bacteria. Have the bacterial concentration in your drinking water tested by an independent laboratory. Call the Water Quality Association at (708) 505-0160 or the American Council of Independent Laboratories at (202) 887-5872 for the name of a certified laboratory near your home.

The quality of bottled water is completely unregulated. Some bottled water comes from municipal water supplies. To discover the source of any bottled water, call the bottler and request documentation about the nature and purity of the source. Bottled water that comes from municipal water supplies or lakes should be treated by reverse osmosis before being bottled, if it is to be considered safe.

Avoid using ice unless you feel secure about the purity of the water from which it was made. Remember that automatic ice makers use unfiltered tapwater. Freezing kills most parasites but does not kill bacteria.

Use pure water for brushing your teeth and rinsing your toothbrush.

(c) Peel all fruits and vegetables, unless they are to be thoroughly cooked. Wash your hands afterwards. If you cannot peel them, soak them for fifteen minutes in a solution made by adding one teaspoon of three per cent hydrogen peroxide to two quarts of water and then rinsing thoroughly with filtered water.

(d) When eating out, only eat food that has been cooked just before it is served to you. In many restaurants and delicatessens, soups, sauces and stews are frequently stored in large containers, often left uncovered on the floor and reheated in a microwave oven. Microwave cooking does not kill Salmonella and other strains of pathogenic bacteria. It is safest to eat food that is fairly plain and to avoid soup, unless you know how food is handled in the restaurant where you are eating.

(e) Avoid salad bars. At first glance, salad bars seem like a good place to get healthy food in a hurry. Look again. Some years ago the Wall Street Journal sent a reporter to investigate the cleanliness of salad bars in different parts of the country. Problems were rampant and they lay not only with the restaurant but with the clientele. People are unsanitary in their use of salad bars. They sometimes sample food and put it back. The handles of the serving utensils frequently fall into the food trays, providing an opportunity for contamination.

(f) Do not eat food that has been prepared by a street vendor.

(g) Avoid restaurants where there are flies. Flies can spread parasitic cysts and pathogenic bacteria.

(h) Remember that uncooked meat, fish or poultry are often contaminated with pathogenic bacteria. When preparing your own meals, always keep raw flesh foods away from other food that will be eaten raw, like salad. Cook meat, fish and poultry well and wash your hands after handling them. Also wash the utensils you use to cut them. People have become ill by handling chicken contaminated with Salmonella (as most American chicken is), and then using a contaminated knife or contaminated fingers to prepare other food that was not to be cooked. To kill Salmonella on utensils, soak them in a solution of chlorox for fifteen minutes, then make sure you rinse the chlorox thoroughly away. Do not use dishrags to wipe off kitchen counters, stoves, sinks and tables. Dishrags actually spread germs around. Use recycled paper towels to mop up the bacteria-laden juices from meat, poultry and fish and either use paper towels or sponges to wipe surfaces. Run the sponges through the dishwasher every day to thoroughly remove bacteria.

Fish is one of the most perishable foods, readily spoiled by bacteria and by natural enzymes contained in the fish's flesh. An investigation by Consumer Reports in 1992 found that almost half the fish they tested were contaminated with fecal bacteria, a sign of improper food handling. When you buy fish, make sure they smell fresh. Cook them well, within a day of their purchase.

Tofu is increasingly popular as a substitute for meat. Tofu that is bought floating in water has high levels of bacterial contamination. Wrapped and sealed tofu is safer. To kill bacteria, tofu should be cooked to an internal temperature of one hundred and sixty degrees.

(i) Watch out for toxic molds. Mold toxins (mycotoxins) may suppress the immune system and cause cancer. Mold toxins frequently contaminate U.S. breakfast cereals, especially bulk delivered organic cereals sold in health food stores and food coops. It is best to buy cereals in vacuum packed, sealed containers. All peanuts and peanut butters are contaminated with mycotoxins called aflatoxins, which are among the most potent promoters of cancer ever studied. Aflatoxin levels are highest in the fresh ground peanut butters found in health food stores and supermarkets. In southern Georgia, heavy consumption of peanuts and grains likely to contain high levels of aflatoxins was associated with an increased rate of mental retardation among local children. Aflatoxin production is inhibited by treating food with sorbic acid, a naturally occurring antifungal, first isolated from unripe berries of mountain ash trees in 1859. Peanut butter preserved with sorbic acid is safer than "fresh" peanut butter.

Refrigerators are a haven for mold, which loves to grow on bruised fruits and vegetables. If a hard food that is uncooked becomes moldy, cut and discard the moldy part and at least one inch of the food in each direction from the site of mold. ("Hard" foods include apples, broccoli, carrots, cauliflower, hard cheese in chunks, garlic cloves, onions, pears, potatoes, squash and turnips.) If a soft food, juice or cooked leftover becomes moldy, throw it all away; do not attempt to salvage any of it. Refrigerated leftovers not consumed within forty eight hours should be discarded even if they are not visibly moldy.