Officials of the state’s principal public health and environmental control agency have summarily dismissed radon gas exposure in homes as a significant problem. Unbelievably, agency personnel have reached this conclusion despite the results of a recent, agency-funded study which found that one of every three houses monitored in Spartanburg County and one of every five houses monitored in Greenville County exceed radon concentration levels at which the US Environmental Protection Agency recommends corrective actions be taken.
Addressing the board of the Department of Health and Environmental Control at its October 1988 meeting, the chief of the Bureau of Radiological Health said, “Basically, we don’t see that a big problem exists in South Carolina with indoor radon.” The DHEC commissioner said, “Through scare tactics added to the news coverage of this national concern, a lot of people are really being ripped off.” And the DHEC board chairman remarked, “Hope the news media is listening to this report today.”
Well, I was listening, and I was very dismayed by the apathy, ignorance and thoughtlessness evidenced by the discussion. I suggest that the DHEC board members and agency staff read and study the report submitted to them by scientists from Clemson University before making disparaging remarks to the news media. If DHEC does not consider indoor radon concentrations to be a “big problem in South Carolina, then perhaps we need to examine very closely how the agency determines what is a problem. Current scientific theory and monitoring data indicate that indoor radon concentrations present one of the greatest public health risks known.
DHEC personnel have apparently based their opinion that the state does not have a “big” problem of radon exposure upon the finding that the percentage of homes surveyed in South Carolina which showed radon concentrations greater than the four picocuries per liter was about half the percentage found in national surveys. The EPA has identified a radon concentration of four picocuries per liter (pCi/L) as the action level for dwellings. EPA recommends that remedial actions be performed for homes with levels greater that found pCi/L.
National surveys show the percentage of homes exceeding four pCi/L to be approximately 10 percent. South Carolina survey data show about 5 percent of homes exceeding four pCi/L. This finding only tells us that our problem is not as severe as other states’. It does not tell us that South Carolina’s problem is not serious. Having 5 percent of homes exceeding the recommended “action” limit is still and extraordinarily large exposure to a very dangerous substance.
Provisional census estimates that in 1987 South Carolina had 1,199,000 households with an average of 2.77 persons per household. If 5 percent of these households are exposed to radon levels greater than four pCi/L, the stat has 166,000 of its citizens at substantial risk of mortality due to lung cancers caused by radioactive decay of indoor concentrations of radon.
A more detailed evaluation of the survey data reveals that the population exposure is probably greater than 5 percent. Indoor radon gas concentrations varied greatly across the state. The list of counties with the largest percentages of homes showing radon levels greater than 4 pCi/L, included many of the more populous counties of the state, including Greenville, Charleston, Richland, Spartanburg, Lexington, Anderson and York counties. When population distribution is taken into account, the estimated percentage of the state’s population exposed to indoor concentrations of radon of four pCi/L or more rises to 7.8 percent, which equates to 263,000 persons.
Why should we be concerned about radon gas concentrations? Of itself, radon in the air poses little threat to human health. The danger comes from the radioactive decay products of radon which can become entrapped in the lungs. When these products decay in the lungs, the emitted radiation causes cell damage which can lead to lung cancer. The threat of lung cancer associated with radon exposure is very high. For exposure to one pCi/L of radon during a 70-year lifetime, the expected mortality due to lung cancer associated with radon in non-smoking males is approximately three out of 1,000. For exposure to four pCi/L, the mortality is about one out of 100, and to 20 pCi/L, the mortality is up to five out of 100. The expected mortality for females is generally lower than for males. However, the mortality for smokers is substantially greater that for non-smokers. At to four pCi/L, the mortality for male smokers is about nine out of 100, and to 20 pCi/L, the mortality is greater than one out of three. These expected mortalities are above and beyond those due to smoking alone.
The magnitude of the health risk posed by a hazardous substance such as radon is determined by the toxicity or mortality of the substance and the level of exposure to the substance in the population. The health risk in South Carolina posed by indoor radon concentrations is very great. Expected lung cancer mortalities are very large at the concentrations found in homes within the state. The number of persons within the state who are potentially exposed to dangerous levels of radon is also very large.
By applying the expected mortalities associated with radon to the distribution of exposures to radon found in the South Carolina survey, one can calculate that, on average, each year 455 persons in the state are expected to die from lung cancer associated with radon exposure. If we accept EPA’s premise that radon exposures in homes can be reduced to the four pCi/L level, then 86 lives per year could be saved. If exposures could be reduced to one pCi/L, then 342 lives per year could be saved. If we extrapolate the South Carolina figures to the nation as a whole, assuming that the national problem in twice as severe as the stat problem, then from 12,000 to 49,000 lives per year could be saved, depending upon the effectiveness of the reduction in radon levels.
The above projections must be taken with a grain of salt because they are based upon a continuous 24-hour-per-day lifetime exposures to the indicated radon levels. This premise is, of course, not valid and, intuitively, we would expect the actual average exposure of a person over his lifetime to be lower that the level found in his home or office. However, this premise is consistent with premises used in estimating risks due to other environmental exposures.
How does t he health risk due to indoor radon compare with other environmentally-related health risks? Radon poses one of the greatest risks known. The health risk due to radon is far greater than those posed by landfilling of solid wastes, landfilling of hazardous wastes, or leaking petroleum products and hazardous substances from underground storage tanks.
Why doesn’t DHEC consider indoor radon concentrations in South Carolina homes to be a serious problem? I doubt it is because agency personnel have serious concerns with the validity of the Clemson study. There has been a very recent epidemiological study released nationally which raises questions concerning predicted mortalities due to radon exposure. However, these study findings, if confirmed, cast doubt not only upon the predicted effects of radon, but also upon all other predictions of cancer due to environmental exposures.
Perhaps DHEC does not consider radon to be a serious problem simply because the problem and its solution does not fit neatly within the functions of the agency. DHEC is, after all, principally a regulatory agency. Clearly, we would not wish to solve the problem by sending the police inspectors into the homes and issuing citations requiring corrective actions to homeowners. Rather, the solution to this radon problem should involve the provision of technical and financial assistance.
Or, perhaps DHEC does not consider radon to be a serious problem because it will not play well in the news media. It lacks the classic scapegoat upon whom the problem can be focused. Radon exposure is a fact of nature. It is not someone else’s waste. There is no villainy, except apathy.
Radon exposure is a problem which has a solution. Unlike the very serious problem of ozone depletion, remedial actions upon radon exposure can be carried out at the state and local levels. Actions can be implemented in homes which will prevent the infiltration radon gas or reduce its concentrations. If current estimates are correct, programs to reduce radon exposures in homes within South Carolina will yield far greater health benefits than many of the issues which now seem to captivate public concern, such as hazardous and radioactive waste disposal. Other problems should not be ignored, but neither should we chase ghosts or squander our efforts. We should guide our efforts using facts, knowledge and reasoned judgment. Decisions based principally upon “what if the worst conceivable event happens” or “you cannot prove it is not so,” yield bad public policy.