Radon in the Workplace

1
Radon in the Workplace

• Luke McCormick
• HTRW-CX
• [phone]
• Luke.I.McCormick_at_nwd02.usace.army.mil

2
Radon

• Naturally Occurring
• Inert Noble Gas
• Colorless
• Odorless
• Radioactive

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Uranium Decay Chain
Radon is decay product of Uranium Radium. All
decay products are radioactive down to stable
Lead-206
Radon has 4 short lived decay products. Radon and
short lived decay products will reach equilibrium
in a few hours.
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Where is Radon Found?
Darker colors have higher radon concentration
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Wide range of Concentrations
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Large Daily Variability
150 pCi/l ?
75 day plot of radon concentration In basement
15 pCi/l ?
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Exposure Pathways

• Radon is inert gas, breathe in-breathe out
• Radon decay products are charged solids
• Attach to dust particles
• Breathed in and trapped in lungs
• Irradiate the lung
• Radon is water soluble
• Agitating water releases dissolved Radon

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Health Effects

• Radon is thought to cause lung cancer
• Uranium miner study showed elevated cancer
  incidence (high concentrations in mines)
• Dr. Cohens study did not see any
• (low concentrations in residences)
• Safety assumes the hazard exists.

9
Regulators

• EPA provides GUIDANCE (not regulation)
• on Radon in the Home (4 pCi/l)
• EPA and NRC regulate Radon from Mill
• Tailings
• OSHA regulates Rn in the Workplace
• (30 pCi/l for a 40 hour work week)
• Army ARs, ETLs, TIs

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Terminology

• Picocurie (pCi) 2.22 decays per minute
• Becquerel 1 decay per second
• Working Level (WL) 1.3 X 105 MeV/liter of air
  from short lived progeny alpha emissions
• about equal to 100 pCi/l Rn-222 in equilibrium
• Working Level Month (WLM) exposure to 1 WL for
  168 Hours

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OSHA Regs.

• Adopted from NRC regulations in 1986
• NRC changed regs in 1992. App.B is different.
• 1-1/4 rem per calendar Quarter Whole Body
• 30 pCi/l average air conc. for Adults
• 3 pCi/l average air conc. for minors

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OSHA Regs. (cont.)

• Survey Suspected Areas
• Post Airborne Radioactivity Areas
• 7.5 pCi/l per 40 hour week average
• Have posted SOPs
• Reports and Records

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Problem areas

• Posting
• High Occupancy Factor Areas
• Minimum Concentrations
• Employees under 18 years old.

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Posting
Caution

• Post all locations over 30 pCi/l
• Occupation factor-hours per week
• the area is occupied
• 300 rule if the occupation factor times
  concentration in pCi/l is over 300 then Post
  Caution-Airborne Radioactivity Area
• 40 hrs X 8 pCi/l 320 ? Post
• 30 hrs X 9 pCi/l 270 ? dont post

Airborne Radioactivity Area
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High Occupancy Factor Areas

• 75 hrs X 4 pCi/l 300 ? Post??
• 75 hrs per week working on emergencies
• 100 hrs X 3 pCi/l 300 ? Post??
• 168 hrs X 1.8 Ci/l 302 ? Post?
• Work site is also residence

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Minimum Concentrations

• Posting below 4 pCi/l
• HQ letter to OSHA submitted
• Present guidance is Post the area, train the
  occupant
• These areas should be very few in number

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Employees under 18 years old.

• The maximum permissible concentration for minors
  is 10 of that for adults
• 3 pCi/l
• Guidance - keep minors out of these areas.
• Needs revisiting survey results since the 4 pCi/l
  guidance was used initially

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The USACE SOP

• Appoint a District Coordinator for Radon
• Test all structures, re-test every 10 years
• Except where no evidence of radon problems
• Remediate in a timely fashion, or limit access
• Notify Occupants
• Train Occupants
• Post signs as needed
• Prepare and post SOPs for airborne radioactivity
  areas
• Keep records of all surveys, incidences,
  training.

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QUESTIONS?

• Luke McCormick, HP HRTW-CX
• CEWNWO-HX-H
• 12565 W. Center Rd.
• Omaha, NE 68144-3869
• [phone]
• Luke.I.McCormick_at_nwd02.usace.army.mil