Correct Answers
Lesson description correct answer -This toxicology lesson discusses the
danger of workers being exposed to toxic chemicals, generally referred to by
OSHA as "chemical exposure in the workplace." The lesson identifies the
forms of toxic substances that workers encounter at hazardous worksites and
their common routes of entry into the human body.
Those taking this lesson will learn about specific poisonous toxins, their target
organs, and how to identify related physical symptoms of exposure so they
can get medical help and protection.
A discussion of permissible exposure limits (PELs) is given to inform
employers and employees as to the safety levels that must be maintained
when working with, or around, hazardous or toxic chemicals.
Introduction correct answer -Toxicology is the study of chemical toxicity.
Toxicity is the degree to which a chemical or substance has a harmful effect on
us or other living things.
What we know today is that the toxic effects of chemicals and other hazardous
substances have been gathered from two sources of information:
Epidemiological Studies correct answer -Epidemiological studies compare
affected people in one group to affected people in another group. Sometimes
the information comes from actual exposures to a chemical in the workplace.
Animal Studies correct answer -Animal studies provide most of what we
know about the dangerous effects of toxic substances. Humans may react
differently than animals exposed to toxic materials
Response to Chemical Exposure correct answer -There are a number of
factors that affect the severity of exposure to a chemical. These factors include
the toxicity of the substance, route of exposure, chemical dose, interaction
with other chemicals, and human response. We will cover each one of these
points in detail.
, Factors Affecting Response to Chemical Exposure correct answer -
Toxicity: Some chemicals produce immediate and dramatic biological effects.
Others may produce no observable effects at all or the effects may be delayed.
Route of exposure: Certain chemicals appear harmless in one form of contact,
such as carbon monoxide on the skin. However, carbon monoxide inhaled into
the lungs causes much more serious effects.
Chemical dose: This is the amount and length of time that one is exposed to a
chemical.
Human Response correct answer -Humans and other living animals vary
in their response to chemical exposure. For some, a certain dose may produce
symptoms of serious illness; for others only mild symptoms may appear; or
there may be no noticeable effect at all. Often a prior exposure to a chemical
affects the way an individual responds to being exposed at a later time. Thus,
there is not only variation between different individuals; there may be
different responses in the same individual at various exposures.
Interaction with other Chemicals correct answer -The study of the
interaction of various chemicals with one another is known as chemistry. An
example is the reaction between acids and bases. The physical and
biochemistry of the living organism is much the same. Chemicals in
combination can produce different biological responses than the responses
seen when exposure is to one chemical alone.
Toxic Substance Forms correct answer -The physical forms in which
chemicals are encountered at a waste site play a large role in routes of entry
into the body.
Solids correct answer -The principal hazard is usually from dusts or fumes
produced when solids change form. For example, polyurethane foam, when
burned, gives off cyanide gas. Routes of entry in this case are inhalation,
ingestion (saliva), and skin absorption.
Fumes correct answer -Tiny particles are produced from heating,
volatilization, and condensation of metals (examples: zinc oxide fumes from
welding of galvanized metal). Routes of entry are inhalation, ingestion