Letter re: EPA/DEP WTC dust cleanup at 114 Liberty Street,

NYC 9/11 Public Portal Document

22

” The EPA background study, op. cit., EPA (April, 2003), did not provide the actual values for the 11 samples where it did detect a-quartz. Table 6-4 of this report only indicates that for one sample, the value was 259 gg/m’, and that for the 34 out of 46 samples where quartz was not detected, EPA assumed that the value was 'A the detection limit, which would be 2 gg/m^. EPA provided the mean concentration for all these values, however. This enabled a back-calculation of the mean of the samples without the outlier.

Note that EPA stated in its background study that eliminating the high outlier of259 jig/m’ was appropriate, and provided an Upper Confidence Limit for a-quartz at 7.8 gg/m’ in Table 8-1 that did not use the hi^ outlier.

“ USEPA, ORD, NCEA (October, 2002) draft Exposure and Human Health Evaluation of Airborne Pollution from the World Trade Center Disaster, EPA Publication No. NCEA - W - 1395 EPA/600/P-2/002A, External Review Draft, http://oaspub.epa.gov/eims/eimscomin.getfile?p_download_id=36387.

Jenkins, C. (July 4,2003) Comments on the EPA Office of Inspector General’s 1/27/03 interim report titled: “EPA’s Response to the World Trade Center Towers Collapse” A DOCUMENTARY BASIS FOR LITIGATION, qp. cit.

“ US EPA, et al. (May, 2003) World Trade Center Indoor Environment Assessment: Selecting Contaminants of Potential Concern and Setting Health-Based Benchmarks, Prepared by the Contaminants of Potential Concern (COPC) Committee of the World Trade Center Indoor Air Task Force Working Group. See p. 15, http.7/www.tera.org/peer/WTC/COPC%20-%20Benchmark%20Report%20with%20appendices.pdf

“ US EPA (October, 2002) DRAFT: Exposure and Human Health Evaluation of Airborne Pollution firom the World Trade Center Disaster National Center for Envirorrmental Assessment Office of Research and Development U.S. Environmental Protection Agency, http://oaspub.epa.gov/eims/eimscomm.getfile?p_down]oad_id=36387

EPA (May, 2003) Final WTC Residential Confirmation Residential Confirmation Cleaning Study Cleaning Study, op. cit. Seep. 15

“ NIOSH. NIOSH Carcinogen List See NIOSH website at http://www.cdc.gov/niosh/npotoccaJrtml

“ NIOSH (May 20,2002) NIOSH UPDATE. NIOSH REPORT ON RESPIRABLE CRYSTALLINE SILICA REVIEWS HEALTH EFFECTS DATA, DISCUSSES RESEARCH NEEDS http://www.cdc.gov/niosh/crysilup.html

NIOSH (1974) Criteria Documents Criteria for a Recommended Standard: Occupational Exposure to Crystalline Silica, DHHS (NIOSH) Publication No. 75-120, http://www.cdc.gov/niosh/75-120.html

“ NIOSH (2002) HAZARD REVIEW Health Effects of Occupational Exposure to Respirable Crystalline Silica http://www.cdc.gov/niosh/02-129I.html

NTP (2002) 10* Report on Carcinogens, http://ehp.niehs.nih.gov/roc/tocl O.html.

The conclusions and opinions are those of the author and do not necessarily reflect those of the U.S. Environmental Protection Agency.

NYC-WTC_000154997