1047RADON
Following the discovery of very high levels of indoor
radon associated with homes in northeastern Pennsylvania
in December of 1984, the New Jersey Department of
Environmental Protection was designated as the lead state
agency to address the potential for radon problems in New
Jersey. The Department was charged with characterizing the
problem as it might exist in New Jersey and developing a
coordinated state response to the problem.
Due to the potentially serious public health implications
of exposure to high levels of radon, the characterization of
New Jersey’s radon problem proceeded simultaneously with
the development of a program to educate the public regard-
ing radon and respond to residents’ needs for reliable radon
testing and radon remediation services.
The current data indicates that New Jersey’s indoor radon
levels are among the highest known and that as many as 1. 6
million homes in New Jersey may be at risk for radon prob-
lems. Approximately one-third of homes studied thus far
test at or above the 4 picocuries per liter guidance level rec-
ommended by the United States Environmental Protection
Agency as a feasible goal for remediation of high concentra-
tions of indoor radon. New Jersey’s response to this problem
is characterized by an integrated multi-agency approach and
the growth of firms providing reliable, regulated radon test-
ing and remediation services in the private sector.BACKGROUNDRadon-222 is the single gaseous isotope among the fourteen
principal decay products composing the 4n + 2 natural decay
series beginning with uranium-238 and terminating in lead-- The principal decay products of this series, their half
lives and principal associated emissions are given in Table 1.^1
The atmospheric concentration of radon varies with loca-
tion, but is typically on the order of 0.1 picocuries per liter
(0.1 pCi/1) over land masses.^2 The average radon concentra-
tion indoors in the United States in not well known, but has
been estimated^3 to be in the range of 1 to 2 pCi/1.
In December of 1984, previously unheard of levels of
radon were found in the home of an engineer, Stanley Watras
who worked at the Limerick Nuclear Generating Station and
lived in the Boyertown, Pennsylvania area.^4 The engineer
had been tripping portal monitor radiation alarms indicat-
ing radioactive material on his clothing when leaving work.
Investigations conducted by the utility and the Pennsylvania
Department of Environmental Resources demonstrated that
the radioactive material on the engineer’s clothing consisted
of the short lived decay products of radon-222 (Po-218
through Po-214 in Table 1) which had originated in his home.
The concentrations of radon in the home ranged as high as
2,600 pCi/1. Subsequent investigations of the area around the
discovery home demonstrated that elevated levels of indoor
radon were common to the area and that the probable source
of the radon was the underlying gramitec rock formation
known as the Reading Prong.^5
In May of 1985, an article^6 by Phillip Shabecoff appeared
in the New York Times reporting the Watras incident and
noting that the Reading Prong ran in a northeasterly direc-
tion out of Pennsylvania, through northern New Jersey and
into New York. The article also identified an increased risk
of lung cancer as a possible outcome of exposure to elevated
levels of radon and its decay products. Immediately, state
agencies in New jersey, particularly the Department of
Environmental Protection, were deluged by telephone and
written requests for information on radon and assistance in
obtaining radon testing services.
Numerous studies have demonstrated the link between
exposure to radon and its decay products in mining situa-
tions and an increased risk of lung cancer.^7 Research efforts
directed at establishing a link between residential exposure
to radon and its decay products have been far more limited in
scope than the mining studies and the data derived from them
are, at best, equivocal.^8 Studies underway now in Sweden,
New Jersey, Pennsylvania and New England may have suf-
ficient power to elucidate the residential exposure risks.
Based primarily on the results of the mining studies he
United States Environmental Protection Agency (EPA) has
estimated that from 5,000 to 20,000 of the 130,000 lung
cancer deaths annually in the United States are attributable
to radon.^9 EPA has further estimated that 1 to 5 persons in
100 exposed in their homes to radon at 4 pCi/1 over a 70 year
lifetime, with 75% occupancy, will develop lung cancer.^10 As
this risk is assumed to be linear, the risk at 200 pCi/1 under
similar conditions of exposure is estimated to be from 44 to
77 in 100. These risks are two or more orders of magnitude
greater than other environmental health risk levels which
traditionally trigger actions to reduce them.
It is important to note that radon itself is not believed
to be the major contributor to the possible development of
lung cancer.^11 As radon is an inert gas there is not preference
for deposition with the body. When radon decays in ambientC018_002_r03.indd 1047C018_002_r03.indd 1047 11/18/2005 11:04:57 AM11/18/2005 11:04:57 AM