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Toxipedia Supported Sites
A Small (brief) Glossary
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 PCB’s 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 |
see below |
|
How the agent gained access to the organism - dermal (skin), inhalation (lung), stomach (ingestion) |
Cigarette smoke - lung, Lead - ingestion |
|
How often the exposure occurs and the time between exposures |
Consider 4 beers in 1 hour vs 4 beers over 4 days. |
|
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 deformaties |
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, Lead - reduced IQ |
LD-50 |
Lethal dose that will kill 50% of a group of animals (little used) |
not used any more |
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 µg/m3 |
Mutagen or Mutagenic |
Any substance that causes alterations in cellular DNA |
|
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 µg/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) |
|
Risk assessment |
The process by which the nature and magnitude of risks are identified. |
|
Risk Communication |
Strategies for effectively communicating information about hazards and risk. |
|
Risk management |
The process of determining whether or how much to reduce risk through our actions. |
|
Susceptibility |
Factors that can increase or decrease the adverse effects of an agent. |
|
Su-Age |
The young and elderly are often more susceptible to the effects of an agent. |
Lead is far more toxic to infants than adults. |
Su-Health |
Disease can increase susceptibility to an agent. |
Liver disease can increase susceptibility. |
Su-Pregnancy |
The many physiological changes that occur during pregnancy alter susceptibility. |
Greater absorption of lead, longer half-life of caffeine. |
Su-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. |
|
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 |
Example
Lorem ipsum dolor sit amet, consectetuer adipiscing elit.
Aliquam fermentum vestibulum est. Sed quis tortor.

