2.3 understanding exposure

• off-gassing: the release of volatile organic compounds from building materials
• indoor air quality: an evaluation of the air within a room or structure
• insecticide: to remove insects that may cause damage or diseasein domestic locations, agriculture, and forestry
• herbicide: to remove unwanted plants that compete for nutrientsand sunlight, affecting the growth of desired plants
• fungicide: to protect crop plants and animals from fungi thatcan cause disease; can also be used to prevent thegrowth of moulds in food or within homes
• organic compounds in pesticides:

  1. insecticides-halogenated hydrocarbons and various organic compounds
  2. herbicide-various organic compounds
  3. fungicide-phenols
• target specificity: the range of organism(s) affected by a pesticide
• broad-spectrum pesticide: a chemical substance that can control the population of a large variety of organisms
• toxicity: the ability of a substance to cause damage to living tissue, impair the function of a body system, or cause death when ingested, inhaled, or absorbed through the skin
• LD50: the dosage of chemical substance, given all at once, that kills half (50%) the population tested within a specific time
• LC50: the concentration of a chemical substance in air or water that kills half (50%) the population tested within a specific time
• drift: the transfer of a pesticide by wind or air current from the location where it is sprayed
• grasshopper effect: the transport of pesticides that results from their evaporation in warmer climates and condensation and deposition in colder climates
• persistence: the resistance of a chemical substance being broken down by biological or chemical means
• fertilizer: a substance containing one or more nutrients required by plants
• organic matter: waste or decaying material from plants or animals
• algal bloom: a rapid increase in the population of algae
• eutrophic: a body of water having excessive plant growth due to a rich supply of nutrients
• toxin: a substance that can have harmful effects
• winterkill: the depth of water organisms caused bu the depletion of oxygen in an ice-covered body of water
• biochemical (biological) oxygen demand (BOD): measure of the amount of oxygen required for the decomposition of organic matter