EPA interim final report on WTC background study, April 2003

NYC 9/11 Public Portal Document

Table 5. Polycyclic Aromatic Hydrocarbons fPAHs)

Tier Action PAHs (settled dust) PAHs (indoor air) Level Basis Level Basis I Aggressive >9 mg/m^ 9 mg/m^ >6 ug/m’ 6ug/m^ cleaning. If levels represents a represents a persist, take 1x10"* risk 1x10"* risk additional action to estimate for a 1 estimate for a 1 reduce exposure. year exposure year exposure n Maintain 9 mg/m^ to 0.3 0.3 mg/m^ 6 ug/m’ to 0.2 0.2 ug/m’ recommended mg/m^ (or represents a ug/m’ (or represents a cleaning methods. background) 1x10"* risk background) 1x10-* risk Consider estimate for a estimate for a additional 30 year 30 year monitoring exposure exposure in No further action <0.3 mg/m’ (or Level could also <0.2 ug/m’ (or Level could background) be set at that backgroimd) also be set at found in that found in background, or background, or unaffected, unaffected, areas, so that no areas, so that increase in risk no increase in due to PAHs risk due to would be PAHs would expected. be expected.

Toxicity criteria for benzo(a)pyrene:

Oral Slope Factor = 7.3 E 00 (mg/kg/day)’' (IRIS, 2002)

(Inhalation cancer risk was calculated by route-to- route extrapolation of oral Slope Factor)

The following carcinogenic PAHs are evaluated as benzo(a)pyTene-equivalents [EPA, 1993]:

Compound Relative Potency Benzo(a)pyrene 1 Benz(a)anthracene 0.1 Benzo(b)fluoranthene 0.1 Benzo(k)fluoranthene 0.01 Chrysene 0.001 Dibenzo(a,h)anthracene 1 Indeno(l ,2,3-c,d)pyrene 0.1

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