Environmental Health and Toxicology Flashcards
Environmental Health
The study of how environmental contaminants impact human health
Environmental health can be broken down by exposures, or the way you are exposed to a specific hazard:
Physical hazards
Chemical hazards
Biological hazards
Cultural hazards
The major focus of environmental health is _.
Disease
Disease can be broken down in to two categories:
Chronic disease Infectious disease (accounts for 26% of the world's deaths; epidemiologic transition)
Toxicology
The study of poisons (toxins) and how they impact the health of living organisms; the dose makes the poison
_ of all US streams and rivers have at least trace amounts of synthetic toxins.
80%
Carcinogens
Toxins that cause cancer; the largest source of cancer worldwide comes from synthetic chemicals; examples: Benzene (polycyclic aromatic hydrocarbon), ethylene oxide, aflatoxin, asbestos
Mutagens
Toxins that cause mutations in the DNA of organisms; can lead to cancer, but mostly cause abnormalities in offspring; examples: sunlight, alkaloid plants
Teratogens
Chemicals that cause harm to an unborn
_ of all birth defects’ causes are unknown.
65%
Allergens
Allergy causing agents that overstimulate the immune systems to incite a response that is unnecessary
Neurotoxins
Chemicals that attack the central nervous system; mostly heavy metals, pesticides, and weaponry; example: Pb and Hg exposure decreases cognitive function
Endocrine Disruptors
Chemicals that interfere with or mimic the endocrine (hormonal) system; excess estrogen in water due to birth control is leading to the feminization of the US; examples: Lake Apopka alligators, Taiwanese boys, Tyrone Hays
Diseases can travel in different ways; these are called routes of exposure:
Inhalation (VOCs, Volatile Organic Compounds)
Ingestion
Dermal absorption
Blood infection
Vector
Anything that carries a disease from one organism to another
Bioaccumulation/Biomagnification
Some toxins can concentrate in certain areas, while others disperse and dilute
Epidemiology
The study of disease occurrence; the idea is to link areas with high disease outbreak to particular outcomes; father is Charles White
Toxicology Studies
Usually contain animal testing through dose-response relationships; LD50/IC50 (LD: lethal dose, IC: inhibitory concentration - for plants) what will kill/inhibit 50% of organisms; threshold values
Acute Exposures
Short period exposures
Chronic Exposures
Long term exposures
Additive Effects
One bad chemical + one bad chemical = 2 bad effects; example: alcohol and caffeine
Synergistic Effects
One bad chemical + one bad chemical = 2 REALLY bad effects; example: alcohol and ibuprofen
Subtractive Effects
One bad chemical + one bad chemical = cancel each other out; example: red wine (or grape juice) and grilled food
Risk Assessment
A tool used by toxicologists to take in to consideration the individual difference of people to help calculate risk; does risk match perception?; innocent until proven guilty approach vs. precautionary approach
Precautionary Approach
FIFRA; of the 100,000 industrial chemicals in our country, only 10% have been tested for toxicity, 2% have been tested for carcinogenicity, mutagenicity, or teratogenicity, and less than 1% are government regulated; what about endocrine, nervous, and immune systems?
