Biomarkers and Mechanistic Approaches in Environmental Epidemiology

Abstract

Environmental epidemiological research involves the identification of relation ships between previous exposures to putative causative agents and subsequent biological effects with study populations. Such relationships are often hard to fully characterize because of difficulties in accurately quantifying exposure, dose, and effect. Biomarkers are indicators, residing in biological systems or samples, of exposure, dose, effect, or susceptibility. Biomarkers of exposure indicate the presence of previous exposure to an environmental agent; a bio marker of dose bears a quantitative relationship to previous exposure or dose; these include exogenous substances, interactive products, or interactions that change the status of the target molecule. Biomarkers of effect indicate the presence and magnitude of a biological response to exposure to an environ mental agent; these include endogenous components, or measures of the func tional capacity or state of the system. Biomarkers of susceptibility indicate an elevated sensitivity to the effects of an environmental agent; these include the presence or absence of an endogenous component, or abnonnal functional responses to an administered challenge. The development of molecular bio markers for environmental agents is based upon specific knowledge of metab olism, interactive product fonnation, and general mechanisms of action. The validation of any biomarker-effect link requires parallel experimental animal and human epidemiological studies.

The light at the end of the tunnel for chemical-specific biomarkers: daylight or headlight?

“…Development of putative biomarkers for environmental agents must be based on specific knowledge of metabolism, product formation and general mechanisms of action (3). Validation of any biomarker-effect link requires parallel experimental and human studies.…”

Diferencias en la salud de jornaleras y jornaleros agrícolas migrantes en Sinaloa, México

“…2,3 Por lo anterior, la determinación del nivel de colinesterasa eritrocítica o plasmática es el indicador biológico más utilizado, tanto en el diagnóstico de intoxicaciones, como en el monitoreo con fines de prevención, estudio o control. [4][5][6][7][8][9][10][11][12][13][14] No obstante, este indicador tiene ciertas limitaciones. Diferentes estudios han mostrado que es posible que se presenten intoxicaciones leves o moderadas o signos y síntomas persistentes, como probable manifestación subaguda, sin alteración de la colinesterasa o con niveles disminuidos dentro de rangos considerados normales, lo cual no tiene una explicación fisiopatológica.…”

Controlling the Avoidable Causes of Cancer: Needs and Opportunities for Etiologic Research

“…For smoking and lung cancer, for example, levels of cotinine, a nicotine metabolite, provide an index of immediate exposure, and levels of some carcinogens and adducts reflecting their binding to DNA can be measured(17). For smoking and lung cancer, for example, levels of cotinine, a nicotine metabolite, provide an index of immediate exposure, and levels of some carcinogens and adducts reflecting their binding to DNA can be measured(17).…”