Benchmarks - indoor contaminants of concern, Apr 2002

z Z FINAL (October 11,2001) ATSDR, CDC, EPA, OSHA Environmental Assessment Workgroup Asbestos Action Levels for World Trade Center Response o o s Action Level & Analysis Method General Public/Recommendations' Supporting hformation- Comments co

'2 o o NYC Background’ PCM/PCMe’ f/cc (see footnotes 2 and 3) • No restriction on access to anyarea. AHERA standards (40 CIR 763); ATSDR Toxicological * Remediation goal is to adiieve background levels. • AHERA guidance for schools requires that when schools are remediated for ■D c CT o' o> Profile for Asbestos; OSHA asbestos, the indoor air levels ofasbestos should besimilar to local outdoor air ■D Ca5 O O> 29CFR 1926.1101 levels. 3. O • Lowest attainablecancer risk 91 O o NYC Background to 0.01 fee PCM/PCMe' • No restriction on access to streets and publid AHERA standards (40 CHL • No significant cancer risk for short-term occupancy for residential and o c commercial building; continue to monitor 763); ATSDR Toxicological school buildings. 3 CD • Evaluate to determine if long-term access is acceptable; Profile for Asbestos; RIS; • AHERA guidance for schools requires that when schools are remediated for evaluate trends over months. OSHA29CFR 1926.1101 asbestos, the indoor air levels ofasbestos should besimilar to local outdoor air ■ Identify source levels ■ Take action, as praaical, to reduce levels to background

70 struaures/mm- TEM • If < than 70 s/mm\ no restrictions on access to buildings AHERA standards (40 ere • AHERA standards applyonly to schools, and by NYC ordinance to • If> 70 s/mm’, resample to confirm and analyze field 763) buildings. blanks; takeaction to identify source and reduce levels to < NYC Clearance standard for • Method sensitivity and counting rules should fellow Appendix A (Table 1) 70 s/mm’ buildings in AHERA 40 CFR 763; Method sensitivity based on # grids analyzed and air sample volume and must be maintained at O.OOS ftcc.

0.01 -0.1 f/cc PCM/PCMe’ • Continue to monitor; consider the need for additional Lowest limit set at l/IO • Long-tarn exposures may increase cancer risk in thegeneral public sampling sites. PEL/REI/TLV; AHERA • Unlike workers thegeneral population, indudes children and sensitive • If air levels are consistently between 0.01 to 0.1 fee, standards (40 Cre763); paeons, does not receive exposure monitoring and does not participate in annual evaluate the need for advisories, the need to limit ATSDR Toxicological Profile health screening access and the need for dust suppression.. for Asbestos; RIS; OSHA29CFR1926.II0I;

>0.1 Pcc PCM/PCMe’ • Evaluate the need to restrict general public access. Unacceptable cancer risk General public should not beexposed to levels suspected of adverse health * Continue to monitor; consider the need for additional following long-term effects upon longterm exposure sampling sites.. exposure; AHERA standards (40 CFR 763); ATSDR Toxicological Profile for Asbestos; RIS; OSHA 29 CFR 1926.1101 SB Action levels (fee) for workers involved in Disaster Response and Recovery Workers Basis Comments emergency response and recovery activities (follow applicable OSHA standards)

0.1 PCM only • Respiratoryprotection required for workers, based on an 8 PEL Value, 0.1 Fee based on an aght hour time weighted avaage, is the hour time weighted average (TWA) of exposureof 0.1 PCM. Occupational Safety and Health Administration’s (OSHA) Permissible Longer shift work, i.e., lower levels ofexposure Exposure; Limit for asbestos, as specified in thcOSHA Construction Industry Regulation fer Asbestos, 29 CFR 1926.1101.