NYC-WTC_000199764

NYC 9/11 Public Portal Document

[Jessica Leighton - RA sitrepO1-29.wpd Page^

Fresh Kills (Jan 28) - Particulate Monitoring (Dataram)

o No particulate measurements were conducted due to inoperative equipment.

Ambient Air Sampling Locations

NYC / ER (Dec 19) - Isocyanates

o Note: The January 28 Sampling Situation Report reported confirmatory isocyanate results. Additional information provided below to supplement original report. o The levels of MDI (4,4'-Methylenediphenyl Isocyanate) identified at Location R (0.0093 mg/m’) and its duplicate sample (0.0067 mg/m’) were both above the EPA Removal Action guidance level (0.0062 mg/m’) based on noncarcinogenic effects. o As reported previously, MDI (4,4'-Methylenediphenyl Isocyanate) was also identified at the Vista Hotel location (0.014 mg/m’), within the Ground Zero work zone, where the OSHA PEL and NIOSH REL are more applicable. 0 The OSHA PEL for MDI is 0.2 mg/m’. The NIOSH REL is 0.05 mg/m’. o Winds were generally steady out of the west during the limited 15-minute time period the samples were collected.

NYC / ER (Jan 21) - Particulate Monitoring (TEOM PM 2.5)

o Park Row (Site 1) - 24-hr average concentration for this period was 20.60 ug/m\ o Chambers St./West St. (Site 2) - 24-hour average concentration for this period was 20.29 ug/m\ o Wall Street - 24-hour average concentrations for this period was 19.61 ug/m \ o All readings below the National Ambient Air Quality Standard for PM2.5 (65 ug/m’).

NYC / ER (Jan 21) - Particulate Monitoring (TEOM PMio)

0 Wall Street - 24-hour average concentrations for this period was 26.28 ug/m’. o All readings below the National Ambient Air Quality Standard for PMi 0 (150 ug/m’).

NYC / ER (Jan 22) - Particulate Monitoring (TEOM PM 2.5)

o Park Row (Site 1) - 24-hr average concentration for this period was 14.82 ug/m\ o Chambers St./West St. (Site 2) - 24-hour average concentration for this period was 12.11 ug/m\

CITY_21MC100_00 2458880

NYC-WTC_000199765