Environmental Health, Pollution, and Toxicology
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Transcript of Environmental Health, Pollution, and Toxicology
Environmental Health, Pollution, and Toxicology
Chapter 8 8.1 Some Basics Environmental health: disease that is
determined by or related to environmental factors such as toxic
chemicals, toxic biological agents, or radiation Disease: an
impairment of an individuals health. 8.1 Some Basics Pollution: an
unwanted change in the environment caused by the introduction of
harmful materials or the production of harmful conditions
Contamination: making something unfit for a particular use through
the introduction of undesirable materials 8.1 Some Basics Toxin:
substances that are poisonous to living things
Toxicology: science that studies toxins or suspected toxins
Carcinogen: toxin that causes cancer 8.1 Some basics Synergism:
interaction of different substances. May amplify or make worse the
effect of just one of those substances. 8.1 Some Basics Point
sources: you can pinpoint exactly where the pollution is coming
from Ex: smoke stacks, pipes discharging into waterways Nonpoint
sources: more diffused and hard to figure out where its coming from
Ex: all the cars on the freeway, urban runoff 8.1 Some Basics
Biomagnification: the chemical accumulates or increases
concentration of a substance as it moves through the food web AKA
bioaccumulation EX: Mercury in fish 8.2 Categories of pollutants
and toxins
Infectious agents caused by bacteria, viruses, or fungus. Think of
some examples? Toxic Heavy Metals (metals with a large atomic
weight) Mercury, lead, cadmium, nickel, etc. Case Study: Minimata
in Japan 8.2 Categories of pollutants and toxins
Organic compounds: compounds that have carbon in them EX:
pesticides, pharmaceuticals, food additives Many manufactured by
people Polluting and toxic They do not easily break down in the
environment They are soluble in fat and can accumulate in living
tissue 8.2 Categories of pollutants and toxins
EX: PCBs shipped from GE in Massachusetts, used in household
appliances They leaked into the soil or damaged PCBs went into the
algae, the insects ate the algae, then they were eaten by shrimp
and fish, eventually eaten by people 8.2 Categories of pollutants
and toxins
Dioxin: one of the most toxic human-made chemicals Not usually made
intentionally; it is a waste product of some chemical reactions Led
to cancer in humans (as well as other animals) Labeled Carcinogen
by EPA STILL hasnt been banned or regulated by government. 8.2
Categories of pollutants and toxins
Hormonally active agents (HAAs) Messed with the hormones of an
animal (including humans!!) Many found in pesticides and herbicides
DDT used as a pesticide, thinned out shells out bald eagle 8.2
Categories of pollutants and toxins
Nuclear Radiation Can lead to serious problems, including cancer
Thermal pollution (heat pollution) heat is released into water or
air Can come from volcanic eruptions, agricultural burning Power
plants use water to cool the equipment down. Can affect wildlife
near by it 8.2. Categories of pollutants and toxins
Particulates: small particles of dust in the air that can come into
our lungs Asbestos: minerals that are in the form of small,
elongated particles Used in houses for insulation 8.2 Categories of
pollutants and toxins
Noise pollution: unwanted sound 8.4 Old and New Environmental
Health Problems
Pandemic disease that spreads rapidly across wide regions of the
planet affecting a high proportion of the population EX: Bubonic
Plague EX: HIV/AIDS Pigs and other animals such as chickens in
commercial farms can increase the possibility of new diseases
evolving and spreading to humans 8.4 Hospitals with large numbers
of sick people can become a breeding ground for disease In 2006, E.
coli spreading 8.5 General Effects of Pollutants
Almost every part of the human body is affected by one pollutant or
another. Dose response: effect of a certain chemical on an
individual depends on the dose EX: Fluorine: a little bit keeps
tooth decay at bay, but too much can lead to osteoporosis, a
disease characterized by loss of bone mass. LD-50: crude
approximation of a chemicals toxicity Dose at which 50% of the
population dies, or the Lethal Dose 50. 8.5 ED-50 (effective dose
50) dose that causes an effect in 50% of the observed subjects
TD-50 (toxic dose 50) is the dose that is toxic to 50% of the
observed subjects. Threshold a level below which no effect occurs
and above which effects begin to occur Tolerance: ability to resist
or withstand stress from exposure to a pollutant or harmful
condition