NYC-WTC_000195863

NYC 9/11 Public Portal Document

O Coast Guard Building - Battery Park (Site 3) - 24-hour average concentrations for this period was 25.03 ug/m^. O All readings below the National Ambient Air Quality Standard for PM2.5 (65 ug/m’).

NYC / ER (Oct 22) - Particulate Monitoring (Dataram) o - ..................................... Particulate levels noted at three locations (Stations L, N, R) were below the OSHA TWA. o Instruments operated between 5/2 to 7 hours. o Station L values ranged from 57.6 to 192.4 ug/m3 with an average of 173.7 ug/m^. o Station N values ranged from 72.3 to 187.4 ug/m3 with an average of 140.7 ug/m’. □ Station R values ranged from 26.7 to 273.2 u^m3 with an average of 77.2 ug'm\ NYC / ER (Oct 21) - Volatile organics (TAGA) O Benzene exceeded OSHA TWA PEL (1 ppm) at two locations on the debris pile in the plume at ground level. O Chlorodifluoromethane (Freon-22) was noted as a Tentatively Identified Compound (TIC) at apparently significant concentrations in samples collected from the debris pile in the plume at ground level.

Bulk/Dust Samples NYC / ER (Oct 10) - Pesticide/PCBs O 2 dust samples obtained from rooftops in the vicinity of the WTC (22 Cortlandt, 7* fl. and 600 Gateway Plaza, 34“* fl.) o Pesticides were not detected. o PCBs detected at trace concentrations well below levels of concern.

NYC / ER (Oct 12) - Asbestos □ Asbestos was detected above 1% chrysotile in 5 of 87 samples collected from structural steel brought to metal recycling facilities. Direct Reading Instruments NYC / ER (Oct 22) O Consistent readings noted above the carbon monoxide NAAQS (8 hr. average) of 9 ppm, but below the NAAQS (1 hr. average) of 35 ppm and the OSHA PEL of 50 ppm. o Indications of low levels of hydrogen fluoride (OSHA PEL == 3 ppm) and sulfur dioxide (OSHA PEL = 5 ppm) well below the respective OSHA PELs (TWA). o Phosgene was not detected during this period.

CITY_21MC100_0 02574659

NYC-WTC_000195864