VOC sampling locations table for Ground Zero area, Jan 2002

NYC 9/11 Public Portal Document

All 21 Ground Zero air samples evaluated for total chromium were collected at Building 5 between September 23 and January 31. Additionally, approximately 512 air samples collected at sites surrounding Ground Zero were evaluated for chromium, including 86 samples collected at landfills and 16 samples fi-om personal air monitors worn by New York City fire department personnel. No exceedences of the OSHA PEL or the ATSDR Intermediate MRL for chromiumVI particulates were detected. However, it was noted that concentrations in the range of 0.20 and 0.40 pg/m’ were measured for about a month month after September 11, to then drop to more typical urban backgrounds less than 0.10 pg/m’

Nickel. Nickel samples evaluated at Ground Zero and at sites surrounding Ground Zero never exceeded the OSHA PEL of 1 mg/m\ On the basis ofsamples evaluated, exposures to nickel were not likely to cause any adverse health effects.

All 21 Ground Zero air samples evaluated for nickel were collected at Building 5 between September 23 and January 31. Additionally, approximately 637 air samples collected at sites surrounding Ground Zero were evaluated for nickel, including 86 samples collected at landfills. No exceedences of the OSHA PEL were detected. Furthermore, and unlike chromium and other contaminants, all measurements from September 11 on at all sites were at background levels.

Polychlorinated Biphenyls. Of the several hundred polychlorinated biphenyl (PCB) air measurements available, only one sample was elevated above 100 nanograms total PCB per cubic meter (ng/m^), at 153 ng total PCB/m\ and only three samples were above 50 ng total PCB/m\ This compares to typical urban background PCB concentrations in the range of 1 - 8 ng total PCB/m^. After a month, nearly all readings were in the range of typical urban PCB concentrations or were not detected. There were no exceedences ofany short-term occupational health benchmark, including the NIOSHREL of 1 *10^ ng/m^ or the OSHA PEL of5*l(f ng/m^. It is concluded that exposures were of minimal concern for cancer risk.

Several hundred PCB air measurements were obtained at a total of 12 locations in the vicinity of Ground Zero fi-om September 16, 2001, through April 24, 2002. The highest PCB air concentration measured was 153 ng PCB/m’, and this occurred on October 2, 2001, at the Ground Zero site, WTC Building 5 SW. Typical urban air concentrations of PCBs are in the range of 1 - 8 ng/m\ The source of these elevated PCB air measurements is speculated to be the smoke emanating fi-om the smoldering fires at Ground Zero. PCBs were entrained in the smoke as a consequence of PCB-containing materials in the WTC buildings. After November 3, 2001, all of the PCB monitoring sites showed results consistent with PCB levels in air that are typical of urban areas of the U.S. A simple screening exercise showed that an incremental lifetime cancer risk due to exposure to short-term elevation of PCBs would be in the range of 10'® or lower, which is judged to be of minimal concern. With respect to non-cancer effects, all PCB air measurements are several orders of magnitude below No Observed Effect Levels (NOELs) in experimental animal studies. In addition, levels of PCBs observed near or at the WTC site are below the NIOSH REL of 1*10^ ng/m^ (NIOSH, 2002), and several

DRAFT-DO NOT QUOTE OR CITE 6 October 2002

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