REQUIREMENTS FOR MONITORING WORKER RADON EXPOSURE
Section 422.70, Conditions of License of the Adopted Rule requires licensees to track, record and report annually radiation exposure to their workers. In addition, radiation exposure shall not exceed 30 pCi/L or 0.3 WL and shall not exceed 4 working level months (WLM) over a 12-month period based on continuous workplace exposure for 40 hours per week, 52 weeks per year.
In addition, Occupational Safety and Health Administration OSHA regulates worker exposure to radon. The OSHA Regulation 29 CFR 1910.1096 (C) (1) references limits set by the Nuclear Regulatory Commission in Title 10 of the Code of Federal Regulations. Part 20 (10 CFR 20) limits exposure to either 30 pCi/L or 0.33 WL and shall not exceed 4 working level months (WLM) over a 12-month period based on continuous work place exposure for 40 hours per week, 52 weeks per year.
Public health officials, radon testing personnel, radon assessment specialists, and radon mitigators all have reasons to spend substantial amounts of time in houses that are known to have greater than average radon concentrations. A few hours of exposure may not seem like a lot, but the time can quickly add up.
Minimizing Worker Radon Exposure
The As Low As Reasonably Achievable (ALARA) principle should be followed when considering work practices and procedures during any radon related activity. Diagnostic radon testing is often performed in homes suspected of having elevated radon concentrations. Testing devices should be deployed and retrieved, spending a minimum amount of time in the lower areas (basement, etc.) while still obtaining any needed information (floor layout, HVAC description, etc.). Recording of data and any discussions with the homeowner or others should be conducted in areas less likely to have elevated radon concentrations.
Diagnostics by its very nature means attempting to locate and identify source points or areas. Introducing ventilation may be impractical and self-defeating during diagnostics, but it should be considered in sites with very elevated ambient radon concentration. (Normally, source points and areas will be easier to identify in these sites). Any intrusive activities should be accompanied by the use of an industrial wet/dry vacuum exhausted to the outside. Sub-slab communication tests should also be performed with exhausts terminating in the outside air. All test holes should be covered over when not being used and carefully sealed when the diagnostics are completed.
All workers, whether performing diagnostics or installation of mitigation systems, shall participate in employee exposure monitoring programs.
Copyright 2003, Great Lakes Center for Occupational & Environmental Safety & Health, School of Public Health, University of Illinois at Chicago