its and vegetables to any toxic substances.
A pesticide only becomes a contaminant when it is present in some food for which its use has not been approved, or when it is present in concentrations exceeding those deemed safe for human consumption (Fan & Jackson, 1989, p. 159). There are various ways by which such contamination might occur. For instance, low levels of biologically persistent chemicals may remain in the environment for long periods of time. Such materials can linger in the soil, or travel through the air and water to expose nontarget crops (Archibald & Winter, 1990, p. 2). Pesticide contamination may also result from illegal application, or unregulated use in foreign countries.
A number of different pesticides are currently employed in the production of food. The most common of these include the insecticides, herbicides, and fungicides. The safety of these substances depends on numerous factors; perhaps the most important, include the procedures followed during their application. These may involve such variables as time, place, and methods of application. Moreover, pesticide toxicity, residue level, food consumption rate, individual physiologic vulnerability, and environmental persistence may all additionally contribute to a pesticide's overall effect (Fan & Jackson, 1989, p. 160).
The pesticide dose acquired through the ingestion of contaminated food is related to the residue level and the quantity of food consumed. Consumption will differ from one individual to the next. Any analyses which include an estimate of food intake must take into account the effects of different diets (Fan & Jackson, 1989, p. 160).
Different persons may also be more or less susceptible to various types of pesticide contamination. In general, young children, pregnant women, and the elderly, are all considered more vulnerable to toxic exposures. Moreover, genetic factors such as enzyme deficiencies or certain disea...