NYC 9/11 Public Portal Document
• NYC / ER (Dec 28) - Particulate Monitoring (Dataram)
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 15.1 to 554.3 ug/m3 with an average of 41.6 ug/m3.
o Station N values ranged from 8.4 to 100.0 ug/m3 with an average of 20.3 ug/m3.
o Station R values ranged from 1.9 to 88.9 ug/m3 with an average of 23.9 ug/m3.
• NYC / ER (Dec 29) - Particulate Monitoring (Dataram)
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 18.8 to 174.3 ug/m3 with an average of 35.4 ug/m3.
o Station N values ranged from 14.2 to 131.2 ug/m3 with an average of 23.7 ug/m3.
o Station R values ranged from 9.6 to 99.9 ug/m3 with an average of 23.2 ug/m3.
• NYC / ER (Dec 30) - Particulate Monitoring (Dataram)
o Particulate levels noted at three locations (Stations L, N, R) were below the OSHA
TWA.
o Instruments operated approximately 6 to 612 hours.
o Station L values ranged from 0.1 to 139.4 ug/m3 with an average of 14.5 ug/m3.
o Station N values ranged from 0.1 to 82.8 ug/m3 with an average of 13.7 ug/m3.
o Station R values ranged from 1.2 to 53.2 ug/m3 with an average of 19.1 ug/m3.
• NYC / ER (Dec 25) - Volatile Organics (Mobile Laboratory)
o Incorrectly noted in December 27 Sampling Situation Report that no samples were
collected on this day.
o Benzene exceeded OSHA TWA PEL (1 ppm) at one location (North Tower) in the debris
area at ground level.
o 2 of the 3 of the other samples (Washing Tent and Austin Tobin Plaza) did not note any
benzene above the detection limit (20 ppbv).
• NYC / ER (Dec 28) - 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 (ranging from 20 ppbv to 50 ppbv) in
3 of the 4 locations monitored (Washing Tent, Austin Tobin Plaza, South Tower),
including in the debris area at ground level.
• NYC / ER (Dec 29) - Volatile Organics (Mobile Laboratory)
NYC-WTC 000130558
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