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Pure Appl. Chem., Vol. 65, No. 9, pp. 2003-2122, 1993.



Glossary for chemists of terms used in toxicology
(IUPAC Recommmendations 1993)


Alphabetical entries

A | B | C | D | E | F | G | H | I | J | K | L | M

N | O | P | Q | R | S | T | U | V | W | X | Y | Z 

1. Unduly rapid or throbbing heartbeat that is noted by a patient; it may be regular or irregular.
2. Undue awareness by a patient of a heartbeat that is otherwise normal.
paraesthesia: Abnormal sensation, as burning or prickling.
paralysis: Loss or impairment of motor function.
para-occupational exposure:
1 Exposure of a worker's family to substances carried from the workplace to the home.
2. Exposure of visitors to substances in the workplace.
parasympatholytic: Producing effects resembling those caused by interruption of the parasympathetic nerve; also called anticholinergic.
parasympathomimetic: Producing effects resembling those caused by stimulation of the parasympathetic nervous system; also called cholinomimetic.
parenteral dosage: Method of introducing substances into an organism avoiding the gastrointestinal tract (subcutaneously, intravenously, intramuscularly etc.).
paresis: Slight or incomplete paralysis.
partition coefficient: Ratio of the distribution of a substance between two phases when the heterogeneous system (of two phases) is in equilibrium; the ratio of concentrations (or, strictly speaking, activities) of the same molecular species in the two phases is constant at constant temperature. The partition coefficients most frequently used in acute toxicology are
lipid/water and octan-1-ol/water distributions.
passive smoking: Inhalation of sidestream smoke by people who do not smoke themselves.
See RT sidestream smoke.
peak daily average concentration of an air pollutant:  See SN maximum average daily concentration of an atmospheric pollutant.
perceived environment or risk: See SN subjective environment.
RT risk perception.
percutaneous: Through the skin following application on the skin.
perinatal: Relating to the period shortly before and after birth; from the twentieth to the twenty-ninth week of gestation to one to four weeks after birth.
peritoneal dialysis: Method of artificial detoxication in which a toxic substance from the body is transferred into liquid that is instilled into the peritoneum. Thus, the employment of the peritoneum surrounding the abdominal cavity as a dialysing membrane for the purpose of removing waste products or toxins accumulated as a result of renal failure.
permissible exposure limit (PEL): Recommendation by US OSHA for TWA concentration that must not be exceeded during any 8-hour work shift of a 40h working week.
RT maximum allowable concentration, threshold limit value, time weighted average concentration (TWAC), exposure limit.
peroxisome: Organelle, similar to a lysosome, characterized by its content of catalase (EC, peroxidase (EC and other oxidative enzymes.
persistence: Attribute of a substance that describes the length of time that the substance remains in a particular environment before it is physically removed or chemically or biologically transformed.
IRPTC, 1982
RT recalcitrance.
personal monitoring: Type of environmental monitoring in which an individual's exposure to a substance is measured and evaluated: this is normally carried out using a personal sampler.
BT monitoring.
RT personal sampler.
personal protective device (PPD): See SN personal protective equipment (PPE).
SN individual protective device (IPD).
personal protective equipment (PPE): Equipment (clothing, gloves, hard hat, respirator and so on) worn by an individual to prevent exposure to a potentially toxic substance.
SN individual protective device (IPD), personal protective device (PPD).
personal sampler: Compact, portable instrument for individual air sampling, measuring, or both, the content of a harmful substance in the respiration zone of a working person.
SN individual monitor.
IRPTC, 1982
pest: Organism that may harm public health, that attacks food and other materials essential to mankind, or otherwise affects human beings adversely.
pesticide: Strictly a substance intended to kill pests: in common usage, any substance used for controlling, preventing, or destroying animal, microbiological or plant pests.
NT fungicide, herbicide, insecticide.
pesticide residue: Pesticide residue is any substance or mixture of substances in food for man or animals resulting from the use of a pesticide and includes any specified derivatives, such as degradation and conversion products, metabolites, reaction products and impurities considered to be of toxicological significance.
phagocytosis: Engulfing and digestion of micro-organisms, other cells, and foreign particles by cells such as phagocytes.
RT macrophage.
pharmaceuticals: Drugs, medical products, medicines, or medicaments.
pharmacodynamics: Process of interaction of pharmacologically active substances with target sites, and the biochemical and physiological consequences leading to therapeutic or adverse effects.
RT adverse effect, target, toxicodynamics.
pharmacogenetics: Study of the influence of hereditary factors on the effects of drugs on individual organisms.
PS toxicogenetics.
RT ecogenetics, polymorphism.
pharmacokinetics: Process of the uptake of drugs by the body, the biotransformation they undergo, the distribution of the drugs and their metabolites in the tissues, and the elimination of the drugs and their metabolites from the body. Both the amounts and the concentrations of the drugs and their metabolites are studied. The term has essentially the same meaning as toxicokinetics, but the latter term should be restricted to the study of substances other than drugs.
BT chemobiokinetics.
PS toxicokinetics.
RT biotransformation, pharmacokinetics.
pharynx: Throat, the part of the digestive tract between the oesophagus below and the mouth and nasal cavities above and in front.
phase 1 reaction (of biotransformation): Enzymic modification of a substance by oxidation, reduction, hydrolysis, hydration, dehydrochlorination or other reactions catalysed by enzymes of the cytosol, of the endoplasmic reticulum (microsomal enzymes) or of other cell organelles.
BT biotransformation.
RT cytochrome P-420, cytochrome P-448, cytochrome P-450, microsome, phase 2 reaction, phase 3 reaction.
phase 2 reaction (of biotransformation): Binding of a substance, or its metabolites from a phase 1 reaction, with endogenous molecules (conjugation), making more water-soluble derivatives that may be excreted in the urine or bile.
BT biotransformation.
RT conjugate, phase 1 reaction, phase 3 reaction.
phase 3 reaction (of biotransformation): Further metabolism of conjugated metabolites produced by phase 2 reactions: it may result in the production of toxic derivatives.
BT biotransformation.
RT conjugate, phase 1 reaction, phase 2 reaction.
phenotype: The observable structural and functional characteristics of an organism determined by its genotype and modulated by its environment.
Nagel et al. (eds), 1991
RT genotype.
pheromone: Substance used in olfactory communication between organisms of the same species eliciting a change in sexual or social behaviour.
SN ectohormone, feromone.
photo-irritation: Inflammation of the skin caused exposure to light, especially that due to metabolites formed in the skin by photolysis.
RT photosensitization, phototoxicity.
photo-oxidant: Substance able to cause oxidation when exposed to light of the appropriate wavelength.
photophobia: Abnormal visual intolerance of light.
photosensitization: Allergic reaction due to a metabolite formed by the influence of light.
phototoxicity: Adverse effects produced by exposure to light energy, especially those produced in the skin.
phytotoxic: Poisonous to plants; inhibiting plant growth.
piscicide: Substance intended to kill fish.
1. Fluid component of blood in which the blood cells and platelets are suspended.
   SN blood plasma.
2. Fluid component of semen produced by the accessory glands, the seminal vesicles, the prostate, and the bulbo-urethral
3. Cell substance outside the nucleus.
   SN cytoplasm.
plasma half-life: See SN elimination half-life.
plasmapheresis: Removal of blood from the body and centrifuging it to obtain plasma and packed red blood cells: the blood cells are resuspended in a physiologically compatible solution (usually type-specific fresh frozen plasma or albumin) and returned to the donor or injected into a patient who requires blood cells rather than whole blood.
plasmid: Autonomous self-replicating extra-chromosomal circular DNA molecule.
pleura: Lining of the lung.
ploidy: Term indicating the number of sets of chromosomes present in an organism.
RT diploid, haploid.
plumbism: Chronic poisoning caused by absorption of lead or lead salts.
SN saturnism.
pneumoconiosis: Usually fibrosis of the lungs that develops owing to (prolonged) inhalation of inorganic or organic dusts. Cause-specific types of pneumoconiosis:
1. anthracosis From coal dust.
2. asbestosis From asbestos dust.
3. byssinosis From cotton dust.
4. siderosis From iron dust.
5. silicosis From silica dust.
6. stannosis From tin dust.
IRPTC, 1982; Parkes, 1982
pneumonitis: Inflammation of the lung.
po: Per os - Latin for by mouth.
point mutation: Reaction that changes a single base pair in DNA.
point source: Single emission source in a defined location.
RT area source.
poison: Substance that, taken into or formed within the organism, impairs the health of the organism and may kill it.
SN toxic substance.
poison-bearing: Containing a poison.
poisoning: Morbid condition produced by a poison
SN intoxication.
pollutant: Any undesirable solid, liquid or gaseous matter in a solid, liquid or gaseous environmental medium: "undesirability" is often concentration-dependent, low concentrations of most substances being tolerable or even essential in many cases. For the meaning of "undesirable" in air pollution contexts, see "pollution". A primary pollutant is one
emitted into the atmosphere, water, sediments or soil from an identifiable source. A secondary pollutant is a pollutant formed by chemical reaction in the atmosphere, water, sediments, or soil.
PS contaminant.
RT pollution, secondary pollutant.
After WHO, 1980
pollution: Introduction of pollutants into a solid, liquid, or gaseous environmental medium, the presence of pollutants in a solid, liquid, or gaseous environmental medium, or any undesirable modification of the composition of a solid, liquid or gaseous environmental medium. In the context of air pollution, an undesirable modification is one that has injurious or deleterious effects.
RT contaminant, pollutant.
ISO, 1979; WHO, 1989a
polyclonal antibody: Antibody produced by a number of different cell types.
BT antibody.
RT monoclonal antibody.
polydipsia: Chronic excessive thirst.
polymorphism (polymorphia) in metabolism: Interindividual variations in metabolism of endo- and exogenous compounds due to genetic influences, leading to enhanced side effects or toxicity of drugs (for example, poor versus fast metabolizers) or to different clinical effects (metabolism of steroid hormones).
RT ecogenetics, pharmacogenetics, toxicogenetics.
polyuria: Excessive production and discharge of urine.
population: In statistics, the totality of items under consideration. A clearly defined part of a population is called a subpopulation. In the case of a random variable, the probability distribution is considered as defining the population of that variable. The term "population segment" is sometimes used as a synonym for subpopulation.
WHO, 1989a
population at risk: Number of persons who can and may develop an adverse health effect and who are potentially exposed to a risk factor under study: for example, all people in a population who have not developed immunity to an infectious disease are at risk of developing that disease if they are exposed to it. People already having chronic disease are excluded from the population at risk in studies of the incidence of the disease.
After WHO, 1979
population critical concentration (PCC): Concentration of a substance in the critical organ at which a specified percentage of the exposed population has reached the individual critical organ concentration. The percentage indicated by PCC-10 for 10 %, PCC-50 for 50 % etc. (similar to the use of the term LD50).
Kjellstrom et al., 1984
population effect: Absolute number or incidence rate of cases occurring in a group of people.
population risk: See SN societal risk
porphyria: Disturbance of porphyrin metabolism characterized by increased formation, accumulation, and excretion of porphyrins and their precursors.
posology: Study of dose in relation to the physiological factors that may influence response such as age of the exposed organisms.
Brown, 1988
potency: Expression of chemical or medicinal activity of a substance as compared to a given or implied standard or reference.
potentiation: Dependent action in which a substance or physical agent at a concentration or dose that does not itself have an adverse effect enhances the harm done by another substance or physical agent.
RT additive effect, antagonism, synergism.
practical certainty (of safety): Numerically specified low risk of exposure to a potentially toxic substance (for example, 1 in 106) or socially acceptable low risk of adverse effects from such an exposure applied to decision making
in regard to chemical safety.
RT risk, safety.
After Duffus, 1986
precision: Measure for the reproducibility of measurements within a set, that is, of the scatter or dispersion of a set about its central value.
Gold, Loening, McNaught and Sehmi,1987
precordial: Pertaining to the region over the heart and lower thorax.
precursor: Substance from which another, usually more biologically active, substance is formed.
predictive validity: Reliability of a measurement expressed in terms of its ability to predict the criterion: an example would be an academic aptitude test that was validated against subsequent academic performance.
Last, 1988
predictive value: Percentage of positive results that are true positives or of negative results that are true negatives.
Galen and Gambino, 1975
RT sensitivity, specificity.
preneoplastic: Before the formation of a tumour.
prevalence: Number of instances of existing cases of a given disease or other condition in a given population at a designated time; sometimes used to mean prevalence rate. When used without qualification, the term usually refers to the situation at a specified point in time (point prevalence).
Last, 1988
RT incidence.
prevalence rate (ratio): Total number of individuals who have an attribute or disease at a particular time (or during a particular period) divided by the population at risk of having the attribute or disease at this point in time or midway through the period.
Last, 1988
RT population at risk.
primary pollutant: See BT pollutant.
primary protection standard: Accepted maximum level of a pollutant (or its indicator) in the target organism, or some part thereof, or an accepted maximum intake of a pollutant or nuisance into the target under specified circumstances.
WHO, 1989a
probit: Probability unit obtained by adding 5 to the normal deviates of a standardized normal distribution of results from a dose response study: addition of 5 removes the complication of handling negative values. A plot of probit against the logarithm of dose or concentration gives a linear plot if the distribution of response is a logarithmic normal one. Estimates of the LD50 and ED50 (or LC50 and EC50) can be obtained from this plot.
procarcinogen: Substance that has to be metabolized before it can induce malignant tumours.
prokaryote: Unicellular organism, characterised by the absence of a membrane-enclosed nucleus. Prokaryotes include bacteria, blue-green algae and mycoplasmas.
RT eukaryote.
After Nagel et al. (eds), 1991
promoter (in oncology): Agent that induces cancer when administered to an animal or human being who has been exposed to a cancer initiator.
RT initiator.
prophage: Latent state of a phage genome in a lysogenic bacterium.
Nagel et al. (eds), 1991
proportional mortality rate (ratio) (PMR): Number of deaths from a given cause in a specified time period, per 100 or per 1000 total deaths in the same time period: can give rise to misleading conclusions if used to compare mortality experience of populations with different causes of death.
Last, 1988
prospective cohort study: See BT cohort study.
proteinuria: Excretion of excessive amounts of protein (derived from blood plasma or kidney tubules) in the urine.
pseudoadaptation: Apparent adaptation of an organism to changing conditions of the environment (especially chemical) associated with stresses in biochemical systems that exceed the limits of normal (homeostatic) mechanisms: essentially there is a temporary concealed pathology that later on can be manifested in the form of explicit pathological changes sometimes referred to as "decompensation."
RT compensation.
psychosis: Any major mental disorder characterized by derangement of the personality and loss of contact with reality.
psychotropic: Exerting an effect upon the mind; capable of modifying mental activity.
public health impact assessment: Applying risk assessment to a specific target population of known size, giving as the end product a quantitative statement about the number of people likely to be affected in a particular population.
BT risk assessment.
pulmonary: Pertaining to the lungs.
purgative: See SN cathartic, laxative.
pyrexia: Condition in which the temperature of a human being or mammal is above normal.
pyrogen: Any substance that produces fever.

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Alphabetical entries

A | B | C | D | E | F | G | H | I | J | K | L | M

N | O | P | Q | R | S | T | U | V | W | X | Y | Z 

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