|
Term |
Definition |
Example |
|
Absorption |
The
process by which an agent is taken into the blood supply or cells of an
organism. |
Absorption
of nicotine by the lungs. |
|
Acute exposure |
A singe or very limited number of doses |
One
alcoholic drink |
|
Acute response |
The response associated with acute exposure |
Drunk
from an evening drinking alcohol |
|
Acute toxicity |
Undesirable effects of an acute exposure |
Hang
over from alcohol |
|
Anemia |
Decreased
ability of blood to transport oxygen |
Fewer
or damaged red blood cells (lead) |
|
Asbestosis |
A
progressive, non-cancerous disease causing shortness of breath from scarring
of the lung due to asbestos exposure |
Asbestosis
workers |
|
Bioaccumulate |
The
ability of some organisms to accumulate specific compounds. |
Fish
accumulate methyl mercury; DDT or PCBs accumulate in fat |
|
Biotransformation |
An
organism changing one substance into another form often to increase excretion
or reduce toxicity |
Bacteria
changing mercury into methyl mercury |
|
Carcinogen
or carcinogenic |
Any
substance that causes cancer |
Asbestos |
|
Chelating Agent |
An agent that binds other agents to
facilitate their excretion |
Used
to treat elevated lead or mercury levels |
|
Chromosome |
Parts of cells responsible for heredity
characteristics -- DNA |
Most
humans have 46 chromosomes |
|
Chronic Toxicity |
Causes health effects from long-term
exposure |
Smoking
cigarettes |
|
Corrosive |
Causes burns to the skin or other body
tissue |
Lye,
strong cleaning agents |
|
Detoxification
or Biotransformation |
The
biochemical process to neutralize a toxicant (i.e. metabolism) or excretion. |
The
metabolism of alcohol. |
|
Distribution |
How
a chemical agent distributes throughout the body. |
PCB's
and pesticides accumulate in fat. |
|
Dose |
A
measured amount of exposure - usually in terms of body weight or sometimes
surface area |
10
mg/kg |
|
Dose
/ response |
The
effect or response is related to the dose or amount of exposure to an agent. |
One
cup of coffee is ok but two or three results in unpleasant effects |
|
Erythema |
Sunburn
inflammation dilation of the blood vessels thus the redness and heat. |
UV
radiation |
|
Excretion |
How
the body removes agents from the body or even cells. |
Mercury
is excreted in the urine. |
|
Exposure |
Duration
and type of contact with an agent |
|
|
Route of exposure |
How
the agent gained access to the organism - dermal (skin), inhalation (lung),
stomach (ingestion) |
Cigarette
smoke - lung Lead
- ingestion |
|
Frequency of exposure |
How
often the exposure occurs and the time between exposures |
Consider
4 beers in 1 hour vs 4 beers over 4 days. |
|
Duration |
How
long the exposure occurs (see acute and chronic exposure) |
Acute
exposure to gas fumes at a gas station or life time exposure to food
additives. |
|
Fetal
Alcohol Syndrome (FAS) |
Pattern
of physical, developmental, and nervous system disabilities seen in babies
born to mothers who consumed alcohol during pregnancy.... |
1
to 3 per 1000 infants effects world wide |
|
Fetal
Alcohol Effect (FAE) |
Similar
to FAS with learning and nervous system disabilities without the obvious
physical deformities |
Incidence
unknown |
|
Half-life |
A
measure of time to reduce the amount of agent by one half. |
The
half-life of caffeine in the blood is 3-4 hrs. |
|
Hazard |
An
agent or situation capable of causing an adverse effect or harm. |
Loud
noise - deafness |
|
Inhalation |
Exposure to and absorption of a compound
via the lung |
Cigarettes
(nicotine) Marijuana
(THC) |
|
Ingestion |
Exposure to and absorption of a compound
via the stomach or intestines |
Food,
coffee (caffeine), lead |
|
LD-50 |
Lethal dose that will kill 50% of a group
of animals (little used) |
Nicotine
(1 mg/kg) |
|
Leukemia |
Cancer of the blood-forming organs of the
bone marrow |
Caused
by benzene |
|
Mesothelioma |
A rare cancer of the thin membranes lining
the lungs almost always related to asbestos exposure. |
Asbestos
workers (increased with smoking) |
|
Metabolism |
Change one substance in another which
usually aids excretion or reduces toxicity |
Caffeine
into less active compounds |
|
Milligram (mg) |
One thousands of a gram |
1
mg |
|
Minimal Risk Levels (MRLs) |
ATSDR definition - An MRL is an estimate
of the daily human exposure to a hazardous substance that is likely to be
without appreciable risk of adverse noncancer health effects over a specified
duration of exposure. |
Inorganic
mercury in air - Inhalation 0.2 ΅g/m3 |
|
Mutagen or Mutagenic |
Any substance that causes alterations in
cellular DNA |
Many
cancer causing agents, radiation |
|
Neurotoxicity |
Produces
an adverse change in the structure or function of the nervous system
following exposure to a chemical or physical agent. |
Mercury,
Lead, pesticides, heron, alcohol etc... |
|
Neurotransmitter |
A
chemical used to communicate between cells of the nervous system |
Dopamine,
serotonin |
|
PCBs |
Polychlorinated
biphenyls used as cooling agent in transforms because of low flammability.
Now banned because of their environmental persistence and bioaccumulation in
fat of many species including whales and humans. |
Memory
lose |
|
Pesticide
|
any substance or mixture of substances intended for preventing, destroying,
repelling or mitigating any insects, rodents, nematodes, fungi, or weeds or
any other form of life declared to be pests.
and any substance or mixture
of substances intended for use as a plant regulator, defoliant or desiccant. Federal
Insecticide, Fungicide, and Rodenticide Act (FIFRA 1947) |
DDT |
|
Pharmacology |
The
study of the beneficial and adverse effects of drugs. |
Benefits
of aspirin or caffeine |
|
Pollutant |
An agent, often released by human activity,
that is adversely effecting the environment |
DDT,
PCBs, mercury, lead, etc
. |
|
Reference Dose (RfD) |
A daily exposure level (dose) that is not
expected to cause any adverse health effects in humans. |
EPA
RfD for methyl mercury - 0.1 ΅g/kg-day |
|
Response |
The reaction to an exposure to or dose of
an agent |
Stomach
ache from eating too many green apples |
|
Risk |
The
probability of injury, disease, loss of function, or death for an individual
or population exposed to a hazardous substance. (Risk = Hazard X Exposure) |
Evaluating
the dose of lead or mercury that causes developmental effects in children |
|
Risk
assessment |
The
process by which the nature and magnitude of risks are identified. |
Reference
dose (RfD) or acceptable daily intake (ADI) |
|
Risk
Communication |
Strategies
for effectively communicating information about hazards and risk. |
Town
meetings, pamphlets, the World Wide Web |
|
Risk
management |
The
process of determining whether or how much to reduce risk through our
actions. |
Hazardous
waste site clean up, removing lead from gasoline |
|
Skin
Absorption |
Exposure
to and absorption of a compound via the skin |
Nicotine
patch, solvents |
|
|
Factors
that can increase or decrease the adverse effects of an agent. |
Developing
organism, childhood, genetics |
|
Age |
The
young and elderly are often more susceptible to the effects of an agent. |
Lead
is far more toxic to infants than adults. |
|
Health |
Disease
can increase susceptibility to an agent. |
Liver
disease can increase susceptibility. |
|
Pregnancy |
The
many physiological changes that occur during pregnancy alter susceptibility. |
Greater
absorption of lead, longer half-life of caffeine. |
|
Sex |
Man
and women differ in their response to agents due to hormonal influences. |
Female
birth control pill is the most obvious. |
|
Teratogen
or Teratogenic |
Any
substance that cause defects in the developing embryo or fetus (birth
defects) |
Alcohol
can cause facial deformities (FAS). |
|
Teratology |
From
the Greek word teras meaning abnormal form, the branch of science that deals
with the causes, mechanisms, manifestations and prevention of congenital
defects. |
Thalidomide
(caused limb deformities in children) |
|
Therapeutic
index |
Measure
on a drugs benefit and safety. A wide index indicates that a drug as few
toxic effects at high levels. |
Wide
index antibiotics Narrow
index - lithium |
|
Toxic
Substance (regulatory term) |
Any
substance that can cause acute or chronic injury to the human body or is
suspected to do so. |
US
NIOSH publishes a list of toxic substances |
|
Toxicant
(poison) |
An
agent cable of causing toxicity a poison |
DDT,
Lead, noise, solvents, food additives, ozone |
|
Toxicity
or Toxic effect |
An
adverse reaction of the organism. |
Soft
egg shells, reduced IQ, cancer |
|
Toxicokinetics
or Pharmacokinetics |
The
study of absorption, distribution and excretion of an agent. |
How
long alcohol stays in the body. |
|
Toxicology |
The study of the adverse effects of
chemical and physical agents on living organisms. |
Study of affects of lead on the
developing nervous system. |
|
Toxicologist |
A
scientist that studies the adverse effects of agents on biological systems |
|
|
Toxin |
A
natural biological agent (from plants, animals, bacteria or fungus) that
cause toxicity. |
Domoic
acid found in shell fish, caffeine |
|
Xenobiotic |
A
foreign compound, i.e. one that is not natural found in an organism |
Caffeine
in humans |