VOC sampling locations table for Ground Zero area, Jan 2002

NYC 9/11 Public Portal Document

industrial production or waste disposal activities.

The potential for very high short-term lead exposures existed during the initial spread of the dust/smoke cloud from the initial WTC collapse; and the ensuing fires, recovery operations, and debris removal may have also posed some lead exposure risks. Examination of air lead data from ORD WTC perimeter sites (Figure 16) and for additional lower Manhattan sites (Figure 20) reveals that 24-hour lead concentrations within (e.g., at WTC Building 5 SW) or at the WTC Ground Zero perimeter (e.g., at Location A, Barclay and W. Broadway; Location B, Church and Dey) approached or exceeded 1.5 pg/m’ on several days in late September/early October (e.g., September 17, 23, 27 and October 4, 5). There appeared, however, to be rapid fallout (deposition) of the lead from air close to the WTC rather than the lead being transported over longer distances. This interpretation is based on the relatively uniform low air lead values (mostly less than 0.5 pg/m^) seen at the EPA ORD 290 Broadway monitoring site (Figure 16) and at several other locations within a few blocks of the WTC (Figure 20). Consistent with the pattern seen in Figure 16 for EPA/ORD WTC perimeter and 290 Broadway monitoring sites, lead elevations at other lower Manhattan sites outside the WTC work zone generally returned to more typical low background concentrations by mid-October. After October 8, none of the air lead concentrations shown by the WTC Trends Report (EPA, 2002a) for any of the lower Manhattan monitoring sites outside WTC Ground Zero approached or exceeded 1.5 pg/m^; in fact, with very few exceptions, nearly all were below 0.5 pg/m’. Thus, prolonged lead concentrations averaged over 90 days during late September to late November, 2001, at WTC perimeter or other nearby lower Manhattan sites did not exceed the EPA Lead NAAQS (i.e., 1.5 pg/m\ 90-day average). The overall pattern of data, coupled with restrictions of vehicular or pedestrian traffic in lower Manhattan areas close to Ground Zero until very late September/early October, make it doubtful that persons outside the Groimd Zero area were exposed sufficiently to airborne lead levels so as to experience any chronic health risks.

There may, however, exist some basis for potential concern with regard to short-term (hours, days) highly elevated lead exposures of individuals working within the Ground Zero perimeter without appropriate respiratory protection. The highest 24-hour lead level shown in Figure 20 was 5.4 ug/m^ at WTC Building 5 on September 24. It is likely that comparable or higher elevations in ambient air may have occurred within Ground Zero on some days preceding the start of EPA monitoring in late September. This possibility and the above-noted data showing air lead values approaching or exceeding 1.5 pg/m^ on certain days during late September and into October at sites within the WTC work zone or at perimeter sites very close to Ground Zero (within 100 - 200 m) suggest that flare-ups of Ground Zero fires or lead emissions associated with recovery and debris removal operations might have posed risks for individuals within the WTC Ground Zero perimeter. The potential risks would probably be of most concern for pregnant women or other women of childbearing age if any were working within Ground Zero without wearing appropriate protective respirators for extended periods during the first 2 to 4 weeks after September 11. OSHA data (http://osha.gov/nyc- disaster/map.html) do indicate that high air lead levels were detected on September 22 (69.3 pg/m\ averaged over 4.5 hr) and September 23 (18.1 pg/m\ averaged over 3 hr) by area monitoring near WTC Building 5 well within the Ground Zero work zone. However, none of the OSHA personal sampling data reported for WTC recovery workers (e..g, ironworker, torch- cutter/bumer) exceeded the OSHA Lead PEL (50 pg/m^, 8-hr average) during late

DRAFT-DO NOT QUOTE OR CITE 61 October 2002

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