One may care about radon in water not because of the direct effects, but because of off-gassing that may occur when the water is agitated or aerated such as during laundry, dishwashing or showering. The rule of thumb is that 10,000 picoCuries per liter (pCi/l) of water translates into about 1 pCI/l average concentration in air.
The EPA Citizen's Guide to Radon flatly recommends testing water whenever both these conditions are met:
The house is supplied by well water, and
The radon concentration (in air) is 4 picoCuries per liter or more.
We would be happy to conduct such a test for you, but cannot in good conscience
recommend it in southern Michigan. In 1993 Protech's founder thought he would
get rich by becoming the first person in Michigan to be EPA-trained for radon-in-water.
The venture was half-successful. He dutifully attended the course at Rutgers,
and since then has never found a problem home in southeast Michigan, not even
in areas known as radon hotspots.
It's interesting to watch the intramural battle at EPA between the indoor air and drinking water factions. The issue is acceptable risk. Water regulations have traditionally been set to achieve at most 1 in 100,000 lifetime fatality risk, leading to a standard on the order of 300 picoCuries per liter of water (roughly equivalent to 0.03 pCi/l in air, or less than 10% of typical fresh air radon content). The indoor air people say this is, well, silly.
20 years assisting clients with radon, lead paint, mold,
and other environmental air quality issues in their homes
Proudly serving the following Southeast Michigan (SE Mich, MI) counties and communities:
Washtenaw County, Livingston County, Lenawee County, Jackson County, Wayne County, Oakland County, Macomb County, Monroe County, Hillsdale County, Ingham County, Lapeer County, Saint Clair County
Addison, Adrian, Allen Park, Ann Arbor, Armada, Auburn Hills, Belleville, Berkley, Beverly Hills, Bingham Farms, Birmingham, Blissfield, Bloomfield Hills, Brighton, Britton, Brooklyn, Canton, Carleton, Chelsea, Chesterfield, Clarkston, Clawson, Clinton, Commerce, Dearborn, Deerfield, Detroit, Dexter, Dundee, Ecorse, Erie, Farmington, Farmington Hills, Ferndale, Flat Rock, Fowlerville, Franklin, Fraser, Garden City, Grass Lake, Grosse Ile, Grosse Pointe, Harper Woods, Hartland, Hillsdale, Highland, Holly, Howell, Hudson, Huntington Woods, Ida, Jackson, Jonesville, Lake Orion, Lansing, Lapeer, Litchfield, Livonia, Macon, Madison Heights, Manchester, Marine City, Mason, Michigan Center, Milan, Milford, Monroe, Morenci, Mount Clemens, New Baltimore, Newport, North Branch, Northville, Novi, Oak Park, Onsted, Pinckney, Pontiac, Port Huron, Plymouth, Redford, Rochester, Rochester Hills, Romeo, Romulus, Roseville, Royal Oak, St. Clair, Saint Clair Shores, Sand Creek, Saline, Shelby, South Lyon, Southfield, Spring Arbor, Sterling Heights, Taylor, Tecumseh, Temperance, Trenton, Troy, Union Lake, Utica, Walled Lake, Warren, Waterford, Wayne, Westland, White Lake, Wixom, Woodhaven, Wyandotte, Ypsilanti, Whitmore Lake, Webberville, Woodville