APES Block 4
23 March 2011
Unit 5 Study Guide
1. Gray zone- the area of suboptimal health between the state of
health and the state of disease. It is a state of unbalance.
2. Pollutants are categorized by arbitrary categories.
a. Heavy metals: mercury, lead, nickel, gold, etc.
b. Toxic pathways: cadmium, coal, mercury
c. Organic compounds: pest control, pharmaceuticals, food
d. Persistent organic pollutants: (POPs)
e. Hormonally active agents
g. Thermal: heat pollution when heat released into water or air
produces undesirable effects
h. Particulates: small particles of dust
Asbestos: minerals that take the form of small, elongated
Electromagnetic fields: microwaves, computers, cellphones
k. Noise pollution: unwanted sound
Voluntary exposure: exposure to toxins and potentially
3. There is controversy over synthetic organic compounds such as
dioxin because they may produce a hazard for decades or
hundreds of years once they are used and dispersed.
4. Biomagnification is the accumulation or increase in concentration
of a substance in living tissue as it moves through a food web.
This is important in toxicology because the chemical elements
released are most concentrated once they reach humans.
5. Changes in abundance: arsenic, asbestos, cadmium. Changes in
distribution: fluoride, particulates, sulfur oxides. Changes in birth
rates: arsenic, lead, POPs. Changes in death rates: Arsenic,
asbestos, beryllium. Changes in growth rates: boron, fluoride,
6. When Paracelsus said “everything is poisonous, yet nothing is
poisonous”, he meant that nothing is poisonous in a small
amount but if there is too much of a substance, anything can be
7. Dose Response is the effect of a certain chemical on an
individual depends on the dose. Does Response indicate the 50%
of the population will be affected with LD-50, TD-50, and ED-50.
8. The four steps of risk assessment: process of determining
adverse environmental health effects to people exposed to