NYC-WTC_000220651

NYC 9/11 Public Portal Document

Mr. Bernard P. Orlan April 18, 2002 Indoor Air Quality Assessment Page 4 P. S. 89M ATC Project No. 15-19125-0297 recommended concentration of 40 pg/m^ for sensitive individuals and children. The outdoor respirable particulate concentration measurements ranged from 105 to 122 pg/m^ with an average of 110 pg/m^. All of the outdoor measurements were above the NPAAQS of 65 pg/m^ 24-hour average concentration of particulate matter 2.5 micrometers or less in aerodynamic diameter and the USEPA recommended concentration of 40 pg/m3 for sensitive individuals and children.

* The measurements made during this assessment were instantaneous readings, the NPAAQS is a 24-hour average.

TVOC Concentrations

TVOCs were not detected anywhere inside the building (0.0 ppm). The outdoor TVOC concentration was also 0.0 ppm.

OBSERVATIONS

During this assessment, ATC noted the following: • The school building was occupied at the time of the assessment. • No smoke odor was detected in the building • The interior of the building appeared clean and free of dust and debris.

FINDINGS

Based on the real-time measurements, the following findings are presented:

1. Concentrations of CO2, CO and TVOCs were below the applicable standards and guidelines. 2. Sixty (60) of the indoor measurements for temperature were above and ten (10) were within the range of 73 to 79°F (at 50 percent relative humidity) as recommended by the ASHRAE Standard 55-1992 during the heating season (wintertime conditions). 3. All of the indoor measurements for relative humidity were within the ASHRAE- recommended range of 30 to 60 percent for occupant comfort. 4. The average PM2 5 concentration for the entire school building was approximately 74 g/m^. Forty-nine (49) of the indoor measurements were above the NPAAQS of 65 pg/m^ 24-hour average concentration of particulate matter 2.5 micrometers or less in aerodynamic diameter. Seventy-five (75) of the eight (80) indoor instantaneous measurements were above the USEPA recommended concentration of 40 pg/m^ for sensitive individuals and children. All of the outdoor measurements were above the NPAAQS of 65 pg/m^ 24-hour average concentration of particulate matter 2.5 micrometers or less in aerodynamic diameter and the USEPA recommended concentiation of 40 pg/m^ for sensitive individuals and children.

CITY_21MC100_002886604

NYC-WTC_000220654