Laserfiche WebLink
wpt" � g leanu Decision <br /> j p t <br /> xt ' <br /> 3 a �r�.1�' ;4 s, a- <br /> * `¢ Fact Sheet <br /> aka� �� •�A�,�-�" <br /> ' ROM.", <br /> Zlixa �i <br /> Q7bf�sY� I a a e q <br /> .'2z a <br /> 5 <br /> The following exposure pathways were idenixfiieclnetnnaneaith risk assessment: <br /> 4 <br /> mwb <br /> ff�g� �a; F�,'@s�. �1 <br /> Breathing contaminated dust(ruiset'6��ymtnehicles or wind)01 <br /> . <br /> Eating contaminated soil(,far ......l g with unwashed hands) <br /> Skin contact with soil <br /> �� <br /> � AM <br /> � g <br /> '0,0!N;", <br /> Exposure to soil and dust is the most si-- can + 'keii <br /> uld be exposed to DDT from these sites. This <br /> is due to the nature of the DDT compoundDD `� n °tpml� ven if soil laden with DDT enters a stream,the <br /> �EEDDT will continue to cling to the soil andettlethe otttvmvthe stream along with the soil. Tests at NCS <br /> i <br />} Stockton have shown that the DDT is not aegaee,�vaterz DDT was detected in a sediment sample <br /> gh ;M <br />+ collected from a drainage ditch located ned ZIWAIT"Ahe drainage ditches will be investigated as part <br /> KIM <br /> of the facility-wide remedial investigation.oectentaof DDT in the ditches and whether it poses a <br /> hazard. In air,DDT-contaminated dust gyelesoafoteund surface and clings to soil. <br /> T. <br /> .......... " <br /> ����� <br /> i In addition to identifying exposure pathwas; he ,mpessmentesates po <br /> timptential risk. Risks associated with <br /> [! exposure to potential human carcinogens art; �ressedan�t,eus ;the incremental probability of an individual <br /> NZ <br /> developing cancer over a lifetime as a direesxdt is �suze o he.chemical. The term"incremental <br /> probabil-ity" refers to a risk of developing cancer itt. s risk of developing cancer if not exposed to <br /> the site. The risks are calculated using spLn individual's exposures. These assumptions <br /> would have to be met in order for an indiv a Iie�culated incremental cancer risk. For example,an <br /> incremental cancer risk of 1 in 1 million(I �Socaa� €th�xposure to DDT in soil means that.the probability <br /> i <br /> of an exposed individual developing cance�` natnpos�fe�il is l in 1 million,provided that he or she is <br /> exposed under the assumptions used to ca d61QM � s exposure for 30 years for 350 days per year). <br /> The National Oil and Hazardous Substan�-_., n ency,Plan(NCP)is the federal regulation <br /> governing the environmental cleanup of ftockton,and it defines acceptable risk ranges. <br /> According to the NCP,the acceptable risk In <br /> } <br /> For Sites 4 SG 5H and IAS-9,the estim it! DT-contaminated soil was greater than 1 in - <br /> 10,000{101}for each site(for example, 1(0. I� �lo.,:gr of DDT contamination in an industrial area). <br /> This is defined in the NCP as an unacceptale4xs ►� tnpte the Navy to remove the contaminated soil <br /> from Sites 4,5G and 511 and restrict usea thetadt�, The soil that was removed from the sites is <br /> safely stored inside protective covers{tarp � a �ssihity of exposure;however,the soil must be <br /> treated to reduce DDT to levels that are prai Ve� eai andthe environment. The soil at IAS-9 <br /> continues to pose an unacceptable risk an vet'and treated or contained in such a way as to <br /> prevent exposure. j <br /> ' *Words in bold are defined in the aglossazy <br /> 6 <br /> r _ <br />