Microsoft Word Marcellus Radon doc

Radon Dilution in the Home and Potential Health Impacts

Given the radon concentration in natural gas arriving at the kitchen stove, the next issue is the dilution of radon within the apartment or home. This will allow us to determine the radon concentration within the home and the health impact to residents who use natural gas.

Johnson bases his dilution factor of 7111 on two values. First, he assumes the volume of a home, which he estimates at 8000 cubic feet (or 226.6 cubic meters). Secondly, he , figures the expected number of air exchanges as one per hour. An air exchange is the amount of time to replace the entire air volume of a dwelling.

We base our calculations on data from the US Environmental Protection Agency. On the basis of the EPA Factors Handbook¹⁵, we take the volume of a dwelling as 183 cubic meters, rather than 226.6 cubic meters used by Johnson. This smaller volume is more representative of the size of an apartment in New York City.

For the number of air exchanges per hour, rather than one per hour, we take 0.71 air exchanges per hour. This is also more representative of New York City apartments¹⁶. With these changes, the dilution factor of 7111 is substantially modified. The factor of 7111 is multiplied by 0.57 and becomes 4053. This increases the radon concentration within a dwelling, as compared to Johnson’s calculations.

To obtain the radon concentration within the home, we divide the radon concentration entering the home via a kitchen stove by the dilution factor of 4053, As seen in Table 3, the indoor concentrations range between 0.0187 pCi/L to 0.482 pCi/L.

Assuming a person resides in the home 70% of the time, we can determine the risk to a resident of developing lung cancer. The risk is based on a US Environmental Protection Agency analysis¹⁷. As seen in Table 3, the risk of developing cancer in a lifetime ranges from 1 in 10,000 to 1 in 391, an extremely high number. One then multiplies this risk by the number of persons who are potentially at risk.

The number of persons potentially at risk in New York State can be roughly determined by the number of kitchen stoves fueled by natural gas in New York State multiplied by the number of persons in a household. According to the US Department of Energy¹⁸, the number of households with natural gas fueled stoves in New York State is 4.4 million.

From the 2010 Census, the average number of persons per household in New York State is 2.69. Thus 11.9 million persons in New York State are potentially at risk. Multiplying the lifetime risk of inhaling radon gas by the number of persons in New York State at risk, we finally determine the potential number of lung cancers as ranging between 1183 to 30,484, out of a population at risk of 11.9 million. This is a major environmental impact and a public health impact that the New York Department of Environmental Conservation must carefully assess.