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

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

3. 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

4. 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

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

6. 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

7. 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

8. 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

12. 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

13. 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)

14. 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

15. 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

16. 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)

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

18. 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
>30 CO
COHb
EOS 2%
10%
*Adverse effects don’t conclude reproductive and carcinogenic health effects