VOC sampling locations table for Ground Zero area, Jan 2002

NYC 9/11 Public Portal Document

Section VI. Data on Indoor and Occupational Exposures

This section provides a summary of data that are available, or that are being generated, from_ Ground Zero sites where rescue, clean-up and other workers may have been present, and on the indoor air environment. The occupational exposure data are related directly only to the workers on Ground Zero who were potentially exposed to contaminants generated during the course of their work. The indoor exposure data relate to residents in buildings off of Ground Zero whose exposure is from contaminated air that may have infiltrated their living or working spaces during or at some point after the disaster. It is emphasized that this section does not provide any human health risk evaluations in the way that ambient air data were evaluated in Section IV, except when summarizing conclusions of the original authors of the data.

VI.a. Data From Ground Zero Relating to Occupational Exposures The Occupational Safety and Health Agency (OSHA) and the National Institute for Occupational Safety and Health (NIOSH) have generated data sets on air quality at Ground Zero. These data sets are summarized below. Further information on the data and the evaluation of these data can be obtained through the web sites that are identified below.

As part of the evaluations contained in this report, exposures to PCBs and dioxin toxic equivalent (TEQ) concentrations that were measured at Ground Zero were evaluated for on-site workers, which could include workers involved in rescue and clean-up operations. That evaluation is summarized here, with reference to the more detailed evaluations in Sections IV.

VI.a.l. OSHA Data The OSHA data are posted on their Groimd Zero monitoring web-site, at http://www.osha.gov/nyc-disaster/summary.html . Further information on these data can be obtained from OSHA, with contacts provided at, http://www.osha.gov . No interpretative analysis of the OSHA data, other than an identification of exceedences of benchmarks, is provided on the web site or from other available sources.

A total of 1434 asbestos samples (excluding bulk and blank samples) were taken. From September 19-21, 177 samples were taken in the financial district. Since September 21, sampling focused on the WTC site and those workers working in or immediately next to it. A total of 179 of the samples analyzed exceeded OSHA's PEL of 0.1 free. However, upon further analysis using discriminating counting methods and/or TEM analysis, the number of asbestos fibers found dropped dramatically to below detectable levels or well below 0.1 free.

The web site also summarizes data taken on CO, total dust, respirable silica, several organic compounds including PCBs, PAHs, dioxins, VOCs, and others, ffeon-22, hydrogen fluoride, phosgene, inorganic acids, oxides of nitrogen/sulfur, metals including lead, mercury, arsenic, and others, ionizing radiation, and noise. The web site indicates very few exceedences of OSHA PELs or other relevant benchmarks.

The results for respirable silica suggested some exposure. Of 1353 silica samples, 94 exceeded the PEL. The highest sample result was approximately twenty-one times the OSHA limit (jack hammering concrete 16 feet below grade). The other elevated exposures were

DRAFT-DO NOT QUOTE OR CITE 125 October 2002

NYC-WTC_000148966