NYC-WTC_000199742

NYC 9/11 Public Portal Document

[ Jessica Leighton - RA sitrep12-27.wpd Page 4 |

NYC / ER. (Dec 22) - Particulate Monitoring (Dataram)

o Particulate levels noted at three locations (Stations L, N, R) were below the OSHA TWA. o Instruments operated approximately 5'A to 6 hours. o Station L values ranged from 0.0 to 163.9 ug/m^ with an average of 4.5 ug/mL o Station N values ranged from 0.5 to 27.0 ug/m’ with an average of 4.6 ug/mL o Station R values ranged from 0.0 to 151.4 ug/m’ with an average of 8.1 ug/mL

NYC / ER. (Dec 23) - Particulate Monitoring (Dataram)

o Particulate levels noted at three locations (Stations L, N, R) were below the OSHA TWA. o Instruments operated approximately 5 to 6 hours. o Station L values ranged from 0.0 to 88.8 ug/m’with an average of 27.4 ug/m'. o Station N values ranged from 3.4 to 440.8 ug/m^ with an average of 24.7 ug/m\ o Station R values ranged from 0.1 to 337.7 ug/m^ with an average of 25.1 ug/mL

NYC / ER. (Dec 24) - Particulate Monitoring (Dataram)

o No measurements were taken at the three particulate monitoring locations (Stations L, N, R) due to weather conditions.

NYC / ER (Dec 25) - Particulate Monitoring (Dataram)

o No monitoring conducted.

NYC / ER (Dec 26) - Particulate Monitoring (Dataram)

o Particulate levels noted at three locations (Stations L, N, R) were below the OSHA TWA. o Instruments operated approximately 6/2 to 7 hours. o Station L values ranged from 3.2 to 268.5 ug/m’ with an average of 17.7 ug/mL 0 Station N values ranged from 62.9 to 870.8 ug/m’ with an average of 75.2 ug/m\ o Station R values ranged from 4.0 to 1316.2 ug/m’with an average of 21.0 ug/m\

NYC / ER (Dec 19) - 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 2 of the 4 locations monitored (Washing Tent, Austin Tobin Plaza), including in the debris area at ground level.

.. ... J

CITY_21MC100_002458793

NYC-WTC_000199745