Radiation and Public Health
Human beings are constantly exposed to radiation from
natural and manmade sources. On average, 80 percent
of that exposure comes from natural sources, including
terrestrial radiation from radioactive elements such as
uranium, radium, and radon that occur naturally in rocks,
soil and minerals. Radiation exposures vary according to
factors such as an individual's location, lifestyle, occupation
and daily activities.
Radionuclides in Drinking Water
Uranium and radium naturally present in underground
rocks that serve as aquifers may dissolve and enter
groundwater used for drinking water.
Most drinking water
sources have very low
levels of radioactive
contaminants
("radionuclides"), and
are not considered to
be a public health concern. Of the small percentage of
drinking water systems with radioactive contaminant levels
high enough to be of concern, most of the radioactivity is
naturally occurring.
If source water comes from a geographic area where
radiation releases are documented or likely to occur due
to the presence of natural radionuclides in rocks or soil, a
Community Water System (CWS) should test both source
water and water treatment residuals to determine their
radionuclide contents.
Radionuclide Rule
To protect public health, EPA has established drinking
water standards for the following radioactive contaminants:
> Combined radium 226/228 (5 pCi/L);
^ Man-made beta particles and photon emitters
(4 millirems per year);
> Gross alpha activity (15 pCi/L); and
> Uranium (30 M9/L)-
Reducing the exposure to radionuclides in drinking water
and filtration equipment or wastes containing radionuclides
will reduce the risk of cancer. (For details see EPA's
Radionuclide Rule; 66 FR 76708, December 7, 2000.)
Treatment of Water for Human Consumption
Water treatment practices purify water for human consumption
by removing levels of naturally occurring radioactive materials
found in raw water supplies. As large quantities of water are
treated using a filtration process, these contaminants become
concentrated in various filtration media and wastes. Typical
activities during the water treatment process can potentially
bring the worker within close proximity to these concentrated
waste contaminants.
Disposal of Liquid and Solid Waste
Treating water for naturally occurring radionuclides will result
in residual streams requiring disposal which is regulated by
EPA and/or States. Radionuclide concentrations in waste may
determine the disposal options(s) available. These include:
Liquid waste disposal
> Direct discharge to surface water
^ Discharge to Publicly Owned Treatment Works
Solid waste disposal
> Solid waste landfills*
> Hazardous waste landfills
^ Low-level radioactive waste landfills
* Note that landfill owners can refuse to accept any waste.
States may have additional requirements or restrictions
on the disposal of these residuals containing radionuclides.
The practice of land spreading, as an alternative to landfill
disposal of waste treatment residuals, is under review
by EPA.
Additional Resources
> Drinking Water Standards: 40 CFR Parts 8, 141, and 142.
> A Regulator's Guide to Management of Radioactive
Residuals from Drinking Water Treatment Technologies.
U.S. EPA Office of Water, July 2005 (EPA Publication
No. 816-R-05-004).
> Narasimhan, R., J.D. Lowry, J. Culley, and N. Young-
Pong, 2005. Management of the Disposal of Radioactive
Residuals in Drinking Water Treatment. American Water
Works Association (AWWA) Research Foundation.
^ www.epa.gov/radiation/tenorm/water-treatment.html
United States
Environmental Protection Agency
May 2008
EPA 402-F-08-003
Radiation Health
and Safety Practices
for Community
Water Systems
Minimizing Worker Exposure to
Radon and Radiation at Community
Water Systems (CWSs)
Provided by:
Office of Radiation and Indoor Air (ORIA)
Office of Ground Water & Drinking Water (OGWDW)
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What Can a CWS Do to Reduce
Worker Exposure?
Contact your State radiation program for guidance on
conducting radiation surveys at the facility.
Changes to Facility:
> Ventilate all buildings to remove radon gas, especially
those buildings where waste with radium is stored.
> Locate treatment units and waste storage areas as far
away from common areas (e.g., offices) as possible.
^ Survey the system's ambient radiation levels annually
in areas where treatment takes place or material
can accumulate.
Monitor levels of radiation to which staff is exposed.
Provide workers OSHA-approved respirators (not
dust masks) when handling media to minimize
inhalation of radioactive particulates. Note that
respirators are not effective against radon gas.
Provide workers with dosimeters to monitor radon
levels around the facility.
Drinking Water Well
Chemical Addition
I ylllllli
Changes in Personal Hygiene Practices:
> At home, wash work clothing separately.
^ Avoid wearing contaminated clothing into the home.
^ Keep work boots or shoes clean; after potential
contamination, do not bring them home.
Changes in Work Practices:
^ Limit time spent near filtration and aeration equipment,
backwash spray, waste sludges and scales, waste
lagoons, pits and ponds.
^ Follow OSHA measures to limit the potential ingestion
of heavy metals and biological pathogens present
in filters.
> Use protective gloves and frequently wash hands.
> Avoid plunging hands/arms in filtration tanks.
> Avoid eating and drinking in the work area.
^ Shower after exposure to potentially radioactive materials.
^ Launder work clothing at the system if possible.
Water Contaminated
with Radionuclides
Coagulation &
Flocculation
Sedimentation
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f
T
T
T
T
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r
Untreated
Partially Treated
Meets EPA Standards
Radioactively
Contaminated
Wastes
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A
4
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