Biological monitoring دکتر مرجان غروی متخصص طب کار بهداشت و درمان صنعت نفت اصفهان مرکز سلامت کار دانیال

Workplace chemical hazards are assessed in two ways: Exposure assessment Workplace chemical hazards are assessed in two ways: Environmental monitoring Biological monitoring

Environmental monitoring measurement of the external exposure in the work place Sampling: Air Surface Information about potential exposure from ONE rout Rout of exposure Inhalation Skin

Limitations of Env. monitoring Just assesses Exposure NOT absorbed dose Could not measure potential exposure from multiple sources of exposure Just assesses exposure from 1 or 2 rout Inhalation Skin adsorption Doesn’t mention individual differences (in absorption and/or effect of exposure )due to Underline disorders Susceptibility

Limitations of Env. Monitoring (cont.) Some conditions can significantly affect the results Environmental physical condition (temperature, ventilation) method of sampling calibration of instrument

What is Biologic monitoring? measurement of a chemical, it’s metabolite, non- adverse biochemical effect in biological specimen Sampling biological specimen blood Urine Exhaled air Shows quantity of chemical has been absorbed regardless of Workplace and/or off the job exposure Rout of exposure (inhalation/ skin/ GI absorption) Work conditions (cold or warm temperature,…) Individual differences

Uses& Aims of Biological Monitoring Exposure assessment Assessment of adequacy of control interventions Aims Prevention of adverse effects of hazards Intervention much earlier in the progression from exposure to disease

Benefits of Biological Monitoring Assesses absorbed dose of chemicals Assesses internal exposure Individual differences can be mentioned Environmental physical conditions don’t affect the results Provide a better picture of exposure and health risk Complete the results of Env. monitoring

Limitations of Biological Monitoring Some conditions can affect the results: Method of sampling Conditions of transferring samples Calibrations of laboratory instruments Should be done for all exposed workers Expensive Inaccessible and unavailable Usually Can not distinguish workplace exposure from other routs of exposure Off the job (hobbies, habits, other jobs) Environmental (water, food, air pollutions)

Necessary conditions to consider biological monitoring (All must be present) must be present in an available medium (blood, urine, exhaled air) should be suitable for sampling Determinate (substance, metabolites…) must be convenient and acceptable to the population being tested Sampling method must exist that is practical, accurate, and reproducible Method of analysis of the biomarker should be established for responding to aberrant results (action [plan should be determined) Plan of action

Methodology Timing of collection (the most critical factor): DS (During Shift) EOS (End of Shift) EWW (End of Work Week) L2H, L4H (Last 2 hours or 4 hours of shift) NC (not critical) PNS (Prior to Next Shift) Method of collection Sampling (collector, needle) Transferring Media sampled: blood, urine, exhaled air

How to use biological monitoring Complementary role for other sources of exposure assessment Results should help to determine unauthorized exposure Considering cost effectiveness Considering ethical and social issues

Kinds of Biomarkers Biomarkers of exposure Biomarkers of effect Biomarkers of internal dose Chromium, cadmium, lead Biomarkers of effective dose COHB Biomarkers of effect ZPP (biologic monitoring for lead) Biomarkers of susceptibility PCR or DNA adduct protein (cytochrome P450 family, the glutathione S-transferases, and the N- acetyltransferases)

Regulations in Biological Monitoring Biological monitoring is mandatory just for some chemicals according to source of regulation OSHA regulations NIOSH regulations National regulations

Examples for chemicals that are mandated by OSHA regulations Exposed chemicals determinant media Time of sampling No adverse effect level* Action level Lead Lead, ZPP, blood NC <10 >20 CO COHb EOS 2% 10% *Adverse effects don’t conclude reproductive and carcinogenic health effects