Levels of pollutants and their metabolites: exposures to organic substances.
The measurement of levels of organic pollutants and/or their metabolites in body tissues or fluids are specific markers of internal dose and, provided that the pharmacokinetic properties of the compounds in question are known, these levels may also be used as predictors of effects. Although historical data still remain to be very useful in environmental studies, more reliable exposure measures than combination of environmental levels and such estimators as residential history, job titles, life-style habits, individual perceptions, etc., are highly desirable. This has been clearly demonstrated in studies with 2,3,7,8-tetrachlorndibenzo-p-dioxin (TCDD), where more recent measurements of serum concentrations in persons earlier classified as belonging to exposed groups have indicated that severe misclassifications may have occurred in previously epidemiological studies. This also demonstrates that, in retrospective studies, levels of persistent organic compounds are useful as markers of exposure, as their tissue levels mainly reflect previous exposures. However, most organic compounds are readily metabolized and excreted from the human body, and in many instances it will not be possible with current methodology and instrumentation to detect transient organic pollutants at low levels in the blood. In most cases, the use of urine samples offers a better opportunity to provide samples containing detectable levels. Therefore, the measurement of non-persistent organic substances and/or their metabolites may find potential use in prospective environmental health studies, but the predictive value highly depends on proper timing and frequency of sampling according to their toxicokinetic behaviour. A few examples on the use of organic compounds and/or metabolites as biomarkers are given, e.g., polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs), polybrominated biphenyls (PBBs), ochratoxin A, polycyclic aromatic hydrocarbons (PAHs) and cooked food mutagens.
Larsen
J C
JC
Institute of Toxicology, National Food Agency of Denmark, Søoborg.
D015415:Biomarkers; D001826:Body Fluids / Q000737:chemistry; D002273:Carcinogens / Q000633:toxicity; D004781:Environmental Exposure; D004785:Environmental Pollutants / Q000378:metabolism / Q000493:pharmacokinetics / Q000633:toxicity*; D005502:Food; D006801:Humans; D009153:Mutagens / Q000633:toxicity; D009793:Ochratoxins / Q000633:toxicity; D011078:Polychlorinated Biphenyls / Q000633:toxicity; D011083:Polycyclic Compounds / Q000633:toxicity
D015415:Biomarkers; D002273:Carcinogens; D004785:Environmental Pollutants; D009153:Mutagens; D009793:Ochratoxins; D011083:Polycyclic Compounds; C025589:ochratoxin A; D011078:Polychlorinated Biphenyls