NYC-WTC_000199751

NYC 9/11 Public Portal Document

[Jessica Leighton - RA_sitrepCV07.wpd

o Particulate levels noted at three locations (Stations L, N, R) were below the OSHA TWA. o Instruments operated approximately 6 hours. o Station L values ranged from 29.4 to 190.0 ug/m’ with an average of 46.7 ug/m\ o Station N values ranged from 32.1 to 176.2 ug/m’ with an average of 45.2 ug/m\ o Station R values ranged from 28.7 to 128.4 ug/m’ with an average of 46.4 ug/m\

NYC / ER (Jan 4) - Volatile Organics (Mobile Laboratory)

o Benzene did not exceed OSHA TWA PEL (1 ppm) at any of the four locations monitored, including in the debris area at ground level. o Benzene was not detected above the detection limit (20 ppbv) in 3 of the 4 locations monitored (Washing Tent, Austin Tobin Plaza, and South Tower), including in the debris area at ground level.

NYC / ER (Jan 5) - Volatile Organics (Mobile Laboratory)

o Benzene exceeded OSHA TWA PEL (1 ppm) at one location (North Tower) in the debris area at ground level. o All 3 of the other samples (Washing Tent, Austin Tobin Plaza, and South Tower) did not note any benzene above the detection limit (20 ppbv).

NYC / ER (Jan 6) - Volatile Organics (Mobile Laboratory)

o Benzene exceeded OSHA TWA PEL (1 ppm) at one location (North Tower) in the debris area at ground level. o All 3 of the other samples (Washing Tent, Austin Tobin Plaza, and South Tower) did not note any benzene above the detection limit (20 ppbv).

Direct Reading Instruments

NYC / ER (Jan 4)

o Several readings noted during the afternoon at or above the carbon monxide NAAQS (8-hour average) of 9 ppm. o Otherwise, nothing of significance reported.

NYC/ER(Jan 5)

o Nothing of significance reported.

CITY_21MC100_00 2458804

NYC-WTC_000199754