EPA interim final report on WTC background study, April 2003

NYC 9/11 Public Portal Document

health concern in the form of eye, nose and throat irritation, persisting adverse heath effects would not be anticipated, unless these minerals remained suspended in high concentrations. Indoor and street-level outdoor air sampling done in November and December of2001 show that the levels of these chemicals, over a time-weighted sample, were below levels associated with irritant effects (See Table 1). Although there are methodological difficulties in quantifying these materials by X-ray Diffraction (XRD) techniques, a semi-quantitative screening of the results showed that the air levels were orders of magnitude below occupational standards for irritant effects. However, since the presence of minerals in settled dust indicates there is potential for the materials to be resuspended, these minerals should be evaluated qualitatively. Therefore, although no screening levels are developed for these minerals as COPCs, the Pilot Cleaning Effectiveness Initiative mentioned in the Introduction will report qualitatively on the presence of gypsum, calcite and portlandite, while the quantitative analyses for crystalline silica (a COPC discussed above) are being performed by XRD (following NIOSH Method 7500).

Table 1. Index of NIOSH and OSHA exposure limits and estimated maximum values in Lower Manhattan.

*Maximum Estimated NIOSH REL Mineral OSHA PEL (ug/m’) Value (J) in Lower (ug/m’) Manhattan (ug/m’) 10, ug/m’ (total) 15,000 ug/m’ (total) 14J (PMIOO) Gypsum 5,000 (ug/m^ resp) 5,1SEE (resp) 15J(PM4) 15,000 ug/m^ (total) 95J (PMIOO) Portlandite 5,BSE ug/m^ 5,000 ug/m’ (resp) 84J (PM4) 10,1aSE ug/m^ (total) 15,BEE ug/m^ (total) 14J (PMIOO) Calcite 5,000 ug/m\resp) 5,000 ug/m^ (resp) 10J(PM4) NIOSH = National Institute of Occupational Safety and Health, Centers for Disease Control and Prevention REL = recommended exposure level/limit OSHA = Occupational Safety and Health Administration PEL = permissible exposure limit. resp = respirable * rNYCDQH, 20021

Other Substances that Were not Selected to be COPCs

The following summary is provided for substances that were investigated, but not included on the COPC list. A full discussion of the reasons is provided in Appendix A.

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