Spotlight on Research: Mose and Students’ Research Investigates Radon in Water
Posted: January 13, 2003 at 1:00 am, Last Updated: November 30, -0001 at 12:00 am
By Lynn Burke
Radon inspections have become routine when homes are sold in Northern Virginia. A gas formed by the radioactive decay of uranium, radon can escape from soil into the air and become trapped in basements, increasing the risk of lung cancer or leukemia to those who inhale it. Doug Mose, professor of chemistry at George Mason, and his graduate students have been investigating another source of radon that homeowners in this area should be aware of–well water.
“The average water well in Virginia and Maryland is so radioactive that it’s about 10 times what the EPA [U.S. Environmental Protection Agency] says is relatively safe,” says Mose. Radon in drinking water acts as a general carcinogen in the body. Although the EPA says it does not pose the same level of risk as does radon in the air, the agency is nevertheless promulgating regulations for radon levels in community water systems.
“Radon in drinking water is in many ways an issue that I have the most concern with personally because of its immediate risk in places for people who have water wells,” says Mose. Through testing, Mose and his students have determined that the problem is not present in water from reservoirs, rivers, or bottled water but is limited to water trapped underground. “The problem then is exclusively for people with water wells,” he says.
Mose explains that Northern and Central Virginia is underlain by rock, some of which is extremely radioactive. As groundwater trapped by this rock and in the soil above it sits there, the radon produced easily dissolves into the water. “If you happen to drill in a place where there is a lot of uranium in the soil, then there’s a lot of radon in the drinking water,” says Mose.
Mose and his students have looked at both wells at people’s homes and wells that supply communities. In Fairfax County, only about 10 percent of homes have private small-capacity water wells that produce a few hundreds of gallons a day, but because of the way Prince William County has developed, much of that county’s drinking water comes from large-capacity wells that produce thousands of gallons a day.
Mose says one of the more striking moments he and his students had was during a particular research project in which they measured the radon in water in the homes of several hundred people for free. “In exchange, we got them to fill out a medical history of each family member, and that’s where we saw that there appeared to be a problem,” he says.
When all the information was logged onto a spreadsheet, Mose and his students noticed that as the level of radon in the well water increased so did the incidence of cancer in that household, a trend that has been observed by other researchers, says Mose. The findings initiated a lot of subsequent effort, and now, he and his students through experiments are trying to understand better how it might be treated in people’s homes and exactly where it is a problem.
For the individual homeowner with a water well, the problem can be fairly easily solved, and the solution may already be in place in affected homes. A tank of activated charcoal that works to remove a bad smell and taste from water works very well to remove radon, says Mose. Boiling water will also rid water of radon, he adds.
For a municipality, the cost of solving a radon problem is more complex and more expensive. Mose and his students ran experiments for a large capacity system using an activated charcoal system. The largest experiment involved a couple of tanks that were about 20 feet across and 20 feet high. “If you are dealing with thousands of gallons of water a day, you can imagine the volume of charcoal necessary,” says Mose. He adds that another option would be to run the water through an aeration system, which would move the radon out of the water and up through an exhaust fan. “Well, it’s not cheap to build things like that. You would have to tax the citizens to build and maintain those facilities, and there’s not much of a will for that to happen,” he says.
For the time being, most public suppliers of well water just inform their citizens that their drinking water may contain more radon than it should and recommend that they have their water tested, Mose says. If the radon level is too high, the homeowner is urged to install a radon removal system such as a tank of activated charcoal.
Mose is concerned with the efficacy of this approach. “I don’t really know how many people actually decided to test and fix their water supply,” he says. The EPA’s forthcoming regulations may force public suppliers to do something more.