VOC sampling locations table for Ground Zero area, Jan 2002

NYC 9/11 Public Portal Document

PCM f/cc), respectively.

In a review of indoor air monitoring data from a variety of locations, arithmetic mean concentrations ranged from 3*10'5 7*10"’ PCM free. Levels of asbestos in 94 public buildings that contained asbestos ranged from ND to 0.2 TEM free (ND to 3*10-3 PCM free), with an arithmetic mean concentration of 0.006 TEM free (10-4 PCM free). Analysis of data based on air samples from 198 buildings with asbestos-containing materials (ACM) indicated mean asbestos levels ranging from 4*10'^10 2.43*10’’ TEM free (7*10’’ to 4*10’’ PCM free).

Asbestos concentrations in 41 schools that contained asbestos ranged from ND to 0.1 TEM free (ND to 2*10’’ PCM free), with an arithmetic mean of 0.03 TEM free (5*10^ PCM free). Another study reported average concentrations of airborne asbestos fibers > 5 pm in length of 8*10'5 TEM free and 2.2*10'^ TEM free in 43 non-school buildings and 73 school buildings, respectively (the 60:1 conversion factors would not apply to these data, since the TEM readings were already on fibers >5 pm in width, so they are likely to be more directly comparable to PCM results). In another study in 71 U.S. schools, the mean, the 95 percentile, and the maximum asbestos levels were 1.7*10'^, 1.4*10'^ and 2.3*10 ’ PCM free, respectively.

A study of 49 buildings in the United States reported mean asbestos fiber levels of 9.9*10’ * PCM free in buildings with no ACM, 5.9*10’^ PCM free in buildings with ACM in good condition, and 7.3*10’^ PCM free in buildings with damaged ACM.

In general, concentrations of asbestos in both indoor and outdoor settings and in both rural and urban settings appears to be less than, and by some studies, sometimes substantially less than, 3*10"’ free on a PCM volumetric basis.

IV.e.4. Asbestos Air Monitoring Data at the WTC Three sources of information were used to evaluate the asbestos air monitoring. One was the EPA WTC database itself. Downloads of this database occurred in May of2002, and the data evaluated are current as of about mid-April, 2002. The WTC database includes measurements by several federal, state, and local agencies. The second source of data was the Trends Report dated May 16,2002 (EPA, 2002a). There have been three Trend Reports. Generally, these reports obtain all their data from the EPA WTC database and provide summaries and interpretative analyses. The third source of data is a study commissioned by a “Groxmd Zero Elected Officials Task Force” to principally sample two apartments on September 18,2001 (Chatfield and Kominsky, 2001). While the focus of that study was on the indoor enviromnent (it is reviewed in more detail in Section V), two outdoor air samples were also taken.

The May Trends Report contains a summary of the PCM and TEM data collected between September 12,2001 (the date of the first reported sample), and April 13, 2002, in the lower Manhattan area in the vicinity of Ground Zero. Additional TEM data from the Staten Island Landfill were obtained directly from the Region 2 WTC database. Figures 23 and 24 show the locations of fixed monitors at the Lower Manhattan and Staten Island Landfill areas,

DRAFT~DO NOT QUOTE OR CITE 90 October 2002

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