NYC-WTC_000199764

NYC 9/11 Public Portal Document

I Jessica Leighton - RA sitrepO1-29.wpd Page 4 [

i' NYC / ER (Jan 25) - Particulate Monitoring (TEOM PMio)

o Wall Street - 24-hour average concentrations for this period was 21.34 ug/m\ o All readings below the National Ambient Air Quality Standard for PMio (150 ug/m’).

NYC / ER (Jan 26) - Particulate Monitoring (TEOM PM 2.5)

o Park Row (Site 1) - 24-hr average concentration for this period was 11.16 ug/m^. o Chambers St./West St. (Site 2) - 24-hour average concentration for this period was 11.75 ug/m\ o Wall Street - 24-hour average concentrations for this period was 10.06 ug/m\ o All readings below the National Ambient Air Quality Standard for PM2.5 (65 ug/m’).

NYC / ER (Jan 26) - Particulate Monitoring (TEOM PMw)

o Wall Street - 24-hour average concentrations for this period was 19.07 ug/m^. o All readings below the National Ambient Air Quality Standard for PMio (150 ug/m’).

NYC / ER (Jan 28) - Particulate Monitoring (Dataram)

o Particulate levels noted at three locations (Stations L, N, and R) were below the OSHA TWA, o Instruments operated approximately 6 hours. o Station L values ranged from 0.0 to 184.1 ug/m’ with an average of 49.8 ug/m\ o Station N values ranged from 0.0 to 131.6 ug/m’ with an average of 37.3 ug/m’. o Station R values ranged from 0.0 to 140.3 ug/m’ with an average of 36.9 ug/m’.

NYC / ER (Jan 28) - Volatile Organics (Mobile Laboratory)

o Volatile organic compounds were not detected above the detection limit (20 ppbv) in any of the four samples collected (Washing Tent, Austin Tobin Plaza, North Tower, and South Tower), including in the debris area at ground level.

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NYC-WTC_000199767