The Environment and Health - Food hazards

Contaminants found in water often make their way into food products in the cooking and packaging processes, so that many of the comments on water pollution apply here. Some dilute water pollutants become highly concentrated as they pass up the food chain and end in fish or other foods for man. Mercury was cited earlier as one example. Contamination of food with harmful microorganisms is an everpresent concern wherever standards of cleanliness and sanitation are low.


Food entails a whole new set of problems because of the thousands of new ingredients that have been added to it, directly and indirectly, in recent years. These substances include many that have been deemed necessary because of the revolution in food technology: the rise of packaged convenience foods of all kinds. Labels on today's convenience foods list preservatives, nutrients, flavors, colors, and processing agents. The trouble with food additives is that we have had little time to learn about their long-term effects on the body. The Food and Drug Administration does set standards in this area; but in the opinion of many experts, these safeguards are inadequate.

What do the additives do and what are they? What kinds of health hazards do they present? The principal kinds are explained below.


Some additives are simply vitamins and minerals that increase the nutritional value of food. Iodine is added to salt as a goiter preventative; vitamins A and D go into fortified milk. The vitamin and mineral additives are generally beneficial.


Preservatives do what the name implies: they protect against spoilage from molds, yeasts, or bacteria, or prevent oxidation. In the first category are such substances as salt, sugar, vinegar, and—among the controversial additives—sodium nitrate, sodium nitrite, and the sulfiting agents. Where some of these substances guard against illnesses like salmonella and Clostridium botulinum , or botulism, a deadly form of food poisoning, the controversial types may cause serious illnesses and even cancers. For example, nitrates and nitrites can combine with the amines in protein to become nitrosamines, powerful carcinogens.

The antioxidants include lecithin from soybeans, ascorbic acid (vitamin C), and butylated hydroxytoluene (BHT) and butylated hydroxyanisole (BHA). The latter two have been studied because they appear to protect against stomach cancer and liver damage.


Of the more than 1,500 different flavors used in food, some are natural and some synthetic. Among the natural flavors are cinnamon, vanilla, and citrus oils. The synthetics, some of which, like vanillin, have exactly the same chemical compositions as their originals, include monosodium glutamate (MSG), hydrolyzed vegetable protein, and maltol. MSG in particular has become controversial because it can cause “Chinese restaurant syndrome,” with temporary headaches, dizziness, and other unpleasant symptoms.


As a group, the color additives are the most controversial. But they range from beta carotene, a yellow coloring that is used in carrots and sweet potatoes and is beneficial, to a number of coal tar dyes. The FDA has banned as unsafe more than a dozen of the latter in recent years. Others are readily available and are widely used in cereals, baked goods, ice cream, and beverages.

Processing Agents

Many useful processing agents, including yeast and baking soda, are standard kitchen items. They help to control stability, moisture, texture, and other food qualities and characteristics.

Chemical Residues

Some toxic substances found in food appear in the natural environment. An example: the trace amounts of arsenic in cow's milk. Other poisons are introduced into the environment by humans. These, including fungicides, herbicides, and pesticides, have aroused deep concern among environmentalists and a growing number of private physicians.

American farmers use more than 350 approved agricultural chemicals, including about one billion pounds of insecticides annually. Because of such heavy use, about 52 percent of the average American's diet contains one or more kinds of chemical residues. Measured often in parts-per-billion, these can collect in human bodies. Permanent damage can result, according to researchers. Among the compounds are not only weed- and bug-killers like parathion but also growth-enhancers like daminozide.

Researchers warn of other problems with contaminated food. The use of antibiotics in livestock feed, for example, promotes the development of bacteria that resist antibiotics. As one result, humans who eat beef or pork that is improperly cooked may acquire infections that resist penicillin or tetracycline.

Irradiated Foods

Consumer groups have urged further study and cautious use of irradiation as a means of preserving many foods. At least 30 countries have approved radiation exposure to retard spoilage and aging; but concerns remain. They focus particularly on the nutritional losses thay may occur if foods are exposed to more than one kind of preservative, on the effects of radiation exposure on workers handling irradiated foods, and on environmental hazards that could emerge in the transport, storage, and handling of radioactive food-processing wastes.

The possible long-term effects of irradiation have led to other concerns. Radiation kills the salmonella microorganism, but may not affect more virulent and dangerous bacteria such as those responsible for botulism and may, over time, strengthen those other organisms. Irradiation might even produce dangerous mutations of some bacteria. Researchers point out further that meat can become contaminated after irradiation, indicating that other preservatives might have to be used.

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