APES Chapter 17

probability

a mathematical statement about how likely it is that harm with be suffered from a hazard; gives estimate of the likeihood of such an event

DALY (disability adjusted life years)

a measure of the total disease burden in a population (BUT there is a shortage of reliable data on disabilities, and because of disagreements about how to apply them to different age groups

factors used to determine toxicity of a toxin

age and genetic makeup

acute effect

an immediate harmful reaction to an exposure

transmissible disease

an infectious disease that can be transmitter form one person (ex. the flu, HIV)

5 most toxic substances

arsenic, lead, mercury, vinyl chloride, polychlorinated biphenyls

how bacterial diseases spread

as bacterial multiply, viral diseases spread when the virus takes over a cell's genetic machinery to copy itself

hormonally active agents (HAAs)

can mimic hormones

nontransmissible disease

caused by something other than a living organism and does not spread from one person to another (ex. cardiovascular disease)

infectious disease

caused when a pathogen such as a bacterium, virus, or parasite, invades the body and multiplies in its cells/tissues (ex. the flu, HIV)

fear

causes people to overestimate risks and to worry more about unusual than common risks

teratogen

chemicals that can cause harm/birth defects to a fetus/embryo (ex. ethylalcohol)

phthalates

chemicals used to soften PVC (effects: birth defects, liver cancer, kidney and liver damage, etc.)

carcinogen

chemicals, types of radiation/certain viruses that can cause/promote cancer (ex. chloroform, PCBs)

mutagen

chemicals/forms of radiation that cause mutations in the DNA molecules found in cells or that increase the frequency of such changes (HNO2)

epidemiological studies

compare the health of people exposed to a particular or chemical with the health of a similar group of people not exposed to the agent (the control group)

immune system

consists of specialized cells and tissues that protect the body from disease and harmful substances by forming antibodies that render invading agents harmless

response

damage to health resulting from exposure to a chemical

cancer

disease in which malignant cells multiply uncontrollably and create tumors that damage the body and often lead to premature death

hormone blockers

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

LD50, median lethal dose

dose that can kill 50% of the animals in a test population within an 18-day period

pandemic

global epidemic

risk analysis

identifying hazards and evaluating their associated risks, ranking risks, determining options and making decisions about reducing or eliminating risks and informing people

risk management

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

epidemic

large-scale outbreak of an infectious disease in an area or country

toxicity

measure of how harmful a substance is - its ability to cause injury, illness, or death to a living organism

two types of dose-response curves

nonthresold dose-response model: any dosage of a toxic chemical causes harm that increases the dosage threshold dose-response model: threshold dosage must be reached before any detectable harmful effects occur

toxic chemical

one that can cause temporary or permanent harm/death to humans and animals

chronic effect

permanent or long-lasting consequence of exposure to a single dose or to repeated lower doses of a harmful substance

risk

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

three things to prevent infectious diseases from spreading

reduce poverty, improve the quality of drinking water, reduce unnecessary use of antibiotics

possibility

saying an event COULD happen

risk assessment

scientific process of using statistical methods to estimate how much harm a particular hazard can cause to human health or to the environment

dose-response curve

scientists estimate the toxicity of a chemical by determining the effects of various doses of the chemical on test organisms and then by plotting the results in a dose-response curve. One approach is to determine the lethal dose—the amount needed to kill an animal.

factors that affect the level of harm caused by a chemical

solubility, persistence (resistance to breakdown), biological magnification

toxicology

study of the harmful effects of chemicals on humans and other organisms (basically the study of poisons)

how to determine system reliability

system reliability (%) = technological reliability x human reliability

dose

the amount of harmful chemical that a person has injested, inhaled, or absorbed through their skin

tobacco use

the greatest risk in the US

poverty

the greatest risk worldwide

genetic makeup

toxicity depends on this; determines an individual's sensitivity to a particular toxin

flu

viral disease known as the biggest killer

precautionary principle

when there is reasonable but incomplete scientific evidence of irreversible harm to environmental from a proposed existing chemical/technology