VOC sampling locations table for Ground Zero area, Jan 2002

NYC 9/11 Public Portal Document

Zero was to provide results within four hours to alert the Fire Department of New York (FDNY) and the contractors/union health/safety officers working at Ground Zero about conditions that posed immediate health concern to the workers. This sampling was specifically requested by the FDNY and was conducted on a daily basis until the removal activities were completed at Ground Zero (end of May 2002).

As would be expected given this intention, some of the results (including data for benzene, 1,3-butadiene, and styrene) did show exceedences of OSHA limits. A few samples clearly demonstrated exceptionally high measurements of VOCs produced as a result of the disaster. Some samples were collected on top of, and at times, inside the actual debris pile, clearly demonstrating subjective sample design. Because the VOC sampling at the site is not believed to be representative of actual exposures to personnel, it would not be appropriate, or valid, to use these VOC sampling data to analyze worker exposures.

OSHA collected approximately 700 samples for organic compounds, as described in Chapter VI, Most of these samples were taken using personal air monitors, and the samples were taken over longer periods (one to eight hours) and are representative of a worker’s breathing zone exposure. As described in Chapter VI, the OSHA data did not show routine exceedences of screening values (the OSHA standards). For that reason, WTC worker exposures will not be evaluated further. Instead, sampling data that were collected at sites surrounding the WTC site were used to evaluate potential health risks to persons who live or work in surrounding areas.

IV.f.2. Evaluation of VOCs at Sites Surrounding Ground Zero The EPA WTC monitoring database and data from EPA-ORD monitors were used to evaluate VOC exposures to persons who may live and work in areas surrounding the WTC site. Most of the data in the WTC monitoring database are from EPA sampling, but data from other groups (e.g., NYSDEC, OENHP) are also included. Data from the WTC monitoring database covered approximately 27 locations and the EPA-ORD monitors covered 5 locations.

A map of the VOC sampling locations outside of Ground Zero is shown in Figure 33. Table 7 lists the site name, street address, approximate dates of sampling and the approximate number of samples that were taken. Because the number and dates of sampling varied depending on the VOC, the sample dates and number of samples taken shown in the table are for benzene monitoring only. These numbers are, in general, representative of the dates and frequency of sampling of the other VOCs.

Exceedences of benchmark standards were seen for 6 of the 11 VOC compounds evaluated in this assessment, including acetone, benzene, 1,3-butadiene, chloromethane, ethylbenzene, and toluene. 1,4 Dioxane, ethanol, styrene, tetrahydrofuran, and xylenes showed no exceedences of screening benchmarks at any of the sampling sites and are therefore not considered to be contaminants of concern at sites surrounding Ground Zero. Table 8 lists the sites that showed exceedences of screening benchmarks, the dates of exceedence, and the location of the site in relation to the restricted zone. Tables 9-14 show the exceedences of these 6 VOC compounds.

For 5 of these 6 VOC compounds, data were also available for 24-hour samples taken by

DRAFT-DO NOT QUOTE OR CITE 103 October 2002

NYC-WTC_000149047