Chapter 19

the possibility of suffering harm from a hazard that can cause injury, disease, death, economic loss, or environmental damage

the scientific process of estimating how much harm a particular hazard can cause to human health

involves deciding whether or how to reduce a particular risk to a certain level and at what cost

a mathematical statement about how likely one is to suffer from a hazard -Scientists often state probability in terms such as “the lifetime probability of developing lung cancer from smoking a pack of cigarettes a day is 1 in 250”

measures how harmful a substance is in causing injury, illness, or death to a living organism

• a factor that depends the toxicity - the amount of a substance a person has ingested, inhaled, or absorbed through skin

• a factor that depends the toxicity - some molecules are absorbed and stored in specific organs or tissues at higher than normal levels

levels of some potential toxins in the environment are magnified as they pass through food chains and webs

the type and amount of health damage resulting from exposure to a chemical or other agent

a chemical that adversely affects the health of a living human or animal by causing injury, illness, or death

the amount received in one dose that kills 50% of the animals in a test population within a 14-day period

shows the effects of various dosages of a touched agent on a group of test organisms

proves that any dosage of a toxic chemical or ionizing radiation causes harm that increases with the dosage

proves that a threshold dosage must be reached before any detectable harmful effects occur, presumably because the body can repair the damage caused by low dosages of some substances

a chemical, which through its chemical action on life processes, can cause temporary or permanent harm or death to humans or animals -its toxicity is often measured in terms of its medium lethal dose

can harm humans or other animals because it is flammable or explosive or because it can irritate or damage the skin or lungs, interfere with oxygen uptake, or induce allergic reactions

chemicals or ionizing radiation that cause or increase the frequency of random mutations, or changes, in the DNA molecules found in cells

chemicals that cause harm or birth defects to a fetus or embryo

chemicals or ionizing radiation that cause or promote cancer

the growth of a malignant (cancerous) tumor, in which certain cells multiply uncontrollably

when malignant cells break off from tumors and travel in body fluids to other parts of the body

chemicals similar to estrogens - they can disrupt the endocrine systems by attaching to estrogen receptors molecules

disrupt the endocrine system by preventing natural hormones such as androgens (male sex hormones) from attaching to their receptors

When there is a plausible but incomplete scientific evidence of a significant harm to humans or the environment from a proposed or existing chemical or technology, we should take action to prevent or reduce the risk instead of waiting for more conclusive evidence