PHAR 100 - Module 6 Flashcards
environmental toxicant
a chemical that is released into the environment and can produce adverse health effects on living organisms
acute toxicity
refers to a single exposure to a chemical, and often a large dose of the chemical
chronic toxicity
repeated exposure to small doses of a chemical over a long period of time (ex: eating a contaminated food)
gaseous air pollutants
- class of air pollutant
- carbon monoxide and CO2
- nitrogen and sulfur oxides
- hydrogen sulfides
particulate matter
- class of air pollutant
- mixture of tiny particles composed of non-gaseous pollutants
natural sources of air pollutants
volcanoes, forest/prairie fires, dust storms
anthropogenic air pollutants
- man-made air pollutants
- heating and power → combustion of fossil fuels releases CO2, CO
- automobile exhaust → releases smoke, lead particles
- industrial processes → release a wide range of pollutants
human health and air pollution
primary health effect is chemical irritation of the respiratory tract
tobacco smoke
exposure to environmental tobacco smoke carries the same health risks as directly smoking
insecticides
chemicals used to kill insects or to make insects unable to reproduce or develop normally
organochlorine insecticides
- type of insecticide
- increase sensitivity of neurons, resulting in increased CNS stimulation
- ex: DDT - insects developed resistance, levels in food were increasing
- developmental and reproductive effects on animals
organophosphorus insecticides
- type of insecticide
- first synthesized in WWII
- requires metabolic activation to work
- relatively unstable and breakdown in the environment
- irreversibly inhibit acetylcholinesterase, leads to an increase in acetylcholine in nervous tissue
- results in decreased HR, difficultly breathing
herbicides
- chemicals capable of killing or injuring plants
agent orange
- herbicide used in Vietnam war as a defoliant to make it easier to spot targets hidden by trees
- mimics plant growth hormones, causing uncontrolled growth leading to plant death
- major concern is presence of TCDD (introduced during manufacturing process)
TCDD toxicity
- binds to a receptor known as the aryl hydrocarbon receptor, which is involved in the expression of many genes required for normal cellular function
- manifests as aschloracne (severe acne)
- impairs liver and CNS function
paraquat
- type of herbicide
- causes cellular damage, and when ingested, it causes immediate burns of the mouth and stomach
- primary target is the lungs, where cellular damage results in development of fibrous tissues that inhibit the ability to breath