 how you come in contact with it/them. You must also consider the other chemicals you're exposed to and your age, sex, diet, family traits, lifestyle, and state of health.
What is malathion?
Malathion is a pesticide that is used to kill insects on agricultural crops, on stored products, on golf courses, in home gardens, and in outdoor sites where trees and shrubs are grown at home; it is also used to kill mosquitoes and Mediterranean fruit flies (medflies) in large outdoor areas. Additionally, malathion is used to kill fleas on pets and to treat head lice on humans. It is usually sprayed on crops or sprayed from an airplane over wide land areas, especially in the states of California and Florida. Malathion comes in two forms: a pure form of a colorless liquid and a technical-grade solution (brownish-yellow liquid), which contains malathion (greater than 90%) and impurities in a solvent. The technical-grade malathion smells like garlic. Malathion is a manufactured chemical, so it is only found in the environment as a result of its manufacture or use. Malathion has been manufactured in the United States since 1950 and has been used to kill insects on many types of crops since this time. The Food and Drug Administration (FDA) and the EPA allow a maximum amount of 8 parts per million (ppm) of malathion to be present as a residue on specific crops used as foods. Because malathion can be dangerous to humans, the EPA requires that a certain amount of time must pass between the time of application of the insecticide and entry by a worker into a field where the chemical has been applied. Usually, at least 12 hours must pass between application and entry, but in some cases, such as when workers are entering a field to hand harvest or hand prune the crops, time periods as long as 6 days must pass between application and entry into the field. In this way, exposure to malathion can be controlled and accidental exposures can be prevented.
What happens to malathion when it enters the environment?
Once malathion is introduced into the environment, usually from spraying on crops or in wide urban/residential areas, droplets of malathion in the air fall on soil, plants, water, or man-made surfaces. While most of the malathion will stay in the areas where it is applied, some can move to areas away from where it was applied by rain, fog, and wind. Malathion stays in the environment from a few days to several months, but is usually broken down within a few weeks. It is broken down to other chemical compounds by water, sunlight, and bacteria found in soil and water. Malathion does not tend to stick to the soil and is rapidly broken down by bacteria; thus, it is unlikely that malathion will reach groundwater in significant amounts. In water, malathion breaks down quickly by the action of the water and the bacteria in the water. In air, malathion is broken down by reacting with other chemicals formed naturally in the air by sunlight, to form a more toxic product called malaoxon. If malathion is present on dry soil or on man-made surfaces such as sidewalks, pavements, or playground equipment, it usually does not break down as fast as it would in moist soil. For more information, see Chapters 4, 5, and 6.
How might I be exposed to malathion?
Most people are not exposed to malathion in the air that they breathe or on things that they touch, unless they live near areas being sprayed. The people who are at the greatest risk of being exposed to malathion are those who work with this chemical. These include farm workers, chemical sprayers, and people who work in factories that make malathion or other products that contain the chemical. They are exposed to malathion on things they touch where it can pass through their skin, or by breathing it after it has been sprayed. Other people who are at risk of being exposed to malathion are those who use it near their homes and in their gardens, and people living in areas where malathion is sprayed to control medflies or mosquitos. Overexposure to malathion may cause severe poisoning or death. Persons may be expo