Locating, Understanding and Implementing Medical Surveillance Standards

1. Locating, Understanding and Implementing Medical Surveillance Standards

2. Standards have their limits • Type/quality of data • May be outdated • Special considerations: individual differences, nonstandard work schedule, mixtures, moonlighting, etc. • Effect depends on real-world conditions: • Health status • Work rate • Working conditions • May be based on politics, economics, etc.-- not just health!

3. Benefits of Biological Monitoring • Biological monitoring accounts for actual absorption • Can reveal absorption by routes other than inhalation • Can assess effectiveness of PPE • Can show effects of moonlighting/hobbies • Reveals idiosyncratic susceptibility

4. Limits of Biological Monitoring • Very few compounds have adequate pharmacokinetic data • Invasive or inconvenient • Not appropriate for chemicals with immediate effect, such as irritants • Could lead to discrimination • Samples could be analyzed for other agents

5. Agencies and Standards • ACGIH: • TLV, STEL, Ceiling limit • BEI • NIOSH: REL, Criteria Documents • OSHA: • PEL (permanent, interim, ETS) • Action Level • Washington State L & I • ANSI

6. How to find a standard? • OSHA • http://osha.gov/ • Go to “Safety and Health Topics” • “Medical Screening and Surveillance”-- “Medical Surveillance” • Pick a topic! • OSHA standards fall under 29 CFR Part 1910.

7. How to find a standard? • WISHA • Go to WA Dept. of Labor and Industries: http://www.lni.wa.gov/ • “Safety” • “A-Z Safety and Health Topics” • “Medical Surveillance” • Choose one! • WISHA Standards fall under Title 296 WAC.

8. How to find a standard? • NIOSH • http://www.cdc.gov/niosh/ • “Surveillance” • “Medical Test Database” • Or, click on the specific exposure of interest. • e.g., Lead-- ABLES • Methyl Parathion

9. How are we doing? • Straif, K. & Silverstein, M. (1997). “Comparison of U.S. Occupational Safety and Health Standards and German Berufsgenossenschaften guidelines for preventive occupational health examinations.” American Journal of Industrial Medicine 31: 373-380.

10. How can employers implement appropriate screening? • OSHA/WISHA standards for requirements • NIOSH and others for recommendations • Remember standards have limitations! • Consider: • Quality control • Standardization • Centralization/cost-effectiveness • Targeted surveillance • Ethical issues

11. References • Morgan, M.S. & Hostman, S.W. (2008). Section 5: occupational exposure guidelines and standards. In Introduction to Occupational Hygiene. • Morgan, M .S. & Hostman, S.W. (2008). Section 10: biological monitoring. In Introduction to Occupational Hygiene. • Straif, K. & Silverstein, M. (1997). “Comparison of U.S. Occupational Safety and Health Standards and German Berufsgenossenschaften guidelines for preventive occupational health examinations.” American Journal of Industrial Medicine 31: 373-380.

12. Case Presentation • 40 yo undocumented immigrant cotton worker presents with mildly excessive lacrimation, salivation, acute diarrhea. About 5 hours ago he was in the field when an unidentified liquid was spilled on his hands while loading it into a spreader. He was wearing no PPE at the time. No prior medical history available. Patient speaks very broken English. He initially presented, reluctantly, to his supervisor due concerns about mild dyspnea and blurred vision.

13. What would you do to confirm the diagnosis? • Order a serum organophosphate assay to ascertain dangerous levels in blood. • Order erythrocyte count and ESR • Check for depressed levels of erythrocyte cholinesterase activity • No testing indicated, this is primarily a clinical diagnosis.

14. What would you do to confirm the diagnosis? • Order a serum organophosphate assay to ascertain dangerous levels in blood. • Order erythrocyte count and ESR • Check for depressed levels of erythrocyte cholinesterase activity • No testing indicated, this is primarily a clinical diagnosis.

15. As an occupational health worker what would you recommend with regard to the whole work force? • Administer a baseline erythrocyte cholinesterase assay to the entire field worker force. • Recommend thorough physical exam of all field workers in contact with the substance, especially loaders and mixers. • Routinely screen with blood test all workers on a biweekly basis. • Permanently remove any worker from workplace due to recent symptomatic acute exposure

16. As an occupational health worker what would you recommend with regard to the whole work force? • Administer a baseline erythrocyte cholinesterase assay to the entire field worker force. • Recommend thorough physical exam of all field workers in contact with the substance, especially loaders and mixers. • Routinely screen with blood test all workers on a biweekly basis. • Permanently remove any worker from workplace due to recent symptomatic acute exposure

17. Methyl-Parathion Medical screening and surveillance

18. NIOSH Medical Surveillance Rec’s

19. NIOSH Medical Surveillance Rec’s

20. What are some barriers, issues with screening and surveillance?

21. OSHA Medical Surveillance Rec’s(no regulation found)

22. OSHA Medical Monitoring Rec’s • Extrapolated from tetraethyl dithionopyrophosphate TEDP (Sulfotep), another organophospate • Preplacement medical evaluation • pre-exposure red blood cell cholinesterase and plasma cholinesterase • Where no standard exists and the hazard is minimal, evaluationsshould be conducted every 3 to 5 years or as frequently as recommended by an experienced occupational health physician.

23. ACGIH Biological Exposure Determinants (BEIs) 2008 Threshold Limit Values & Biolgical Exposure Indices. American Conference of Governmental Industrial Hygenists

24. ACGIH Biological Exposure Determinants (BEIs) • Based on direct correlation between environmental levels(Threshold Limit Values) and protection against non-systemic effects • BEI: level below which most workers should not experience adverse health effects. • Total p-nitrophenol in urineat end of shift, end of workweek: 0.5mg/g creatinine (Ns) • Cholinesterase activity in red cells, discretionary: 70% of individuals baseline (B, NS, Sq) B – Background: present, in part, due to non-occupational exposure Ns – Nonspecific: Determinant present after exposure to other chemicals Sq – Semi-quantitative: interpretation ambiguous

25. Reference • Criteria for a Recommended Standard: Occupational Exposure to Methyl Parathion. NIOSH Criteria Documents. September 1976. DHHS (NIOSH) Publication No. 77-106. http://www.cdc.gov/niosh/77-106.html Updated 1997. Viewed 25 OCT 2008 • OSHA Health Guidelines: TEDP (Sulfotep) http://www.osha.gov/SLTC/healthguidelines/tedp/recognition.html viewed 25 OCT 2008 • 2008 Threshold Limit Values & Biological Exposure Indices. American Conference of Governmental Industrial Hygienists, Cincinnati, OH www.acgih.org/TLV/Studies.htm

26. Characteristics of US Workers Whose Blood Lead Levels Trigger the Medical Removal Protection Provision, and Conformity With Biological Monitoring Requirements, 2003–2005 SangWoo Tak, ScD,1 Robert J. Roscoe, MS,1 Walter Alarcon, MD,1 Jun Ju, MS,2 John P. Sestito, JD,1 Aaron L. Sussell, PhD,1 and Geoffrey M. Calvert, MD Background: Workers with blood lead levels (BLL) 60 mg/dl (50 mg/dl for construction workers) or with three or more consecutive BLLs over at least 6 months that average 50 mg/dl or greater are required to be removed from work involving lead exposure that exceeds the OSHA action level. This study estimates the proportion of workers with BLLs that trigger the medical removal provision by industry sector, and examines whether workers received appropriate follow-up blood lead testing.

27. Workplace Exposure to Lead OSHA's lead standard (29CFR 1910.1025) Permissible Exposure Limit 50 micrograms per cubic meter of air (µg/m3) Averaged over an 8-hour workday Representative number of employees believed to have the highest exposure levels

28. Action Limit 30 µg/m3 over an 8-hour workday Medical surveillance if action level exceeded>30 days/yr Medical Surveillance Blood lead standard of 40 µg per 100 mL of blood Measure every six months

29. Medical Removal Protection BLL≥ 60 µg/dl General Industry (CFR 1910.1025) BLL≥ 50 µg/dl Construction Average BLL of all tests over a 6-month period (or if there are less than 3 tests over a 6-month period, the average of three consecutive tests) is ≥50 µg/dl

30. biological and medical requirements of the lead standard, at S1910.1025(j) The employer shall provide the required medical surveillance including multiple physician review without cost to employees and at a reasonable time and place. Follow-up blood sampling tests. OSHA requires retesting within 2 weeks and monthly follow-up during the medical removal period.

31. an employee refuses to submit to blood lead testing neither the lead standard, nor any other OSHA standard, makes participation in the medical surveillance program mandatory for the employee. The employer's obligation is to provide medical tests and examinations as required, whether or not an employee cooperates. Substitution of other tests not acceptable i.e. urinary lead, hair lead Recommendation: medical consultation prior to conducting any medical procedures document any employee refusal to undergo it

33. Adults who received follow-upretesting and met eligibility to return to lead work among adults with BLLs triggering medical removal protection (n=208):Based on 17 states reporting all BLLs

34. References: • Medical Surveillance for Lead • http://laborcommission.utah.gov/UOSH/Outreach/ConstructionCD/www.osha.gov/pls/oshaweb/standards-10644.htm