Chemicals may be internalized in the body by ingestion, inhalation, absorption through the skin or by introduction through cuts and abrasions in the skin. Workplace Exposure Workplace exposure may arise through applying pesticides or industrial chemicals, through merely handling them or mixing them for later application, through premature re-entry into recently sprayed areas, through contact with plants or soil, or in the process of cleaning up contaminated sites and transporting or disposing of contaminated soil and water. Indirect Exposure Indirect airborne exposure can arise from overspray, wind drift, and home or workplace application of control chemicals. Indirect waterborne exposure can result from overspray settling onto a stream or lake, from chemicals leeching into surface water from nearby sprayed or contaminated areas, or from leeching into underground water supplies which become part of public or private water supplies. Tertiary or more remote, but still potentially significant, exposure can arise through evaporation of moisture from sprayed fields which yields precipitation many miles downwind from the spray site in areas of human use or in otherwise protected water supplies.
Many chemicals break down into harmless metabolites after exposure to sunlight.
Many others, however, remain intact until they are processed within the human system where they form metabolites or combine with other elements to form new compounds. Frequently the original pesticide or industrial chemical is not detectable in human samples such as urine, saliva or serum, but one or more metabolites can be detected as markers of the human exposure. The EnviroLogix human exposure assays are non-invasive. That is, they do not require blood or serum. The tests rely instead on a urine sample.