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 |
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