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NYC 9/11 Public Portal Document

Mr. Bernard P. Orlan • ‘ 'iFebfuary 27,-20021 Indoor Air Quality Assessment P. S. 89M ATC Project No. 15-19125-02971

Real-Time Environmentai, Measttrements

ATC eollected eighty (80) sets of real-time environmental measurements consisting of seventy (70) from inside the school building and ten (10) from Outdoors. All three floors of the school building were surveyed. These results are described below.

Field data sheets are found in Attachment 1. Readings began at 8:05 A.M and concluded at approximately 11:30 A.M. 1

Temperalure

Indoor dry bulb temperature measurements ranged from 70.9°F to 78.6°F. Twenty-seven (27) of the measurements were above the range of 68 to 75°F (at 50 percent relative humidity) as recommended by the ASHRAF Standard 55-1992 during the heating season (wintertime conditions). The outdoor temperature measurements ranged from 53.0 to 55.0°F.

Relative Humidity

The relative humidity indoors ranged from 24.5 to 34.3 percent. Forty-six (46) of the measurements were within the ASHRAE-recommended range of 30 to 60 percent for occupant comfort. All other measurements were below the ASHRAE-recommended range. The outdoor relative humidity measurements ranged from 48.3 to 48.7 percent.

Carbon Dioxide Concentration

Carbon dioxide concentrations indoors ranged from 574 ppm to 1189 ppm. All of the CO2 measurements were within the ASHRAE Standard 62-1999 recommended maximum concentration of <700 ppm above the background level. The maximum outdoor (background) CO2 concentration was 516 ppm. Therefore, the maximum acceptable level of CO2 at this location was 1216 ppm (background level -t- 700 ppm). The highest CO2 measurement was collected from room 510. Levels above the recommended maximum do not indicate a health risk. Carbon dioxide measurements are used as an indicator of available outside makeup air. The primary source Of CO2 indoors is occupant respiration. The school building was occupied during ATC’s assessment. ■ y

Carbon Monoxide Concentration

Carbon monoxide was not detected indoors (Oppm). These concentrations were below the NPAAQS/ASHRAE guideline of 9 ppm. The outdoor CO concentration was also 0 ppm for all collected readings.

Respirable Purticulates TPM? M

Respirable particulate concentrations* indoors ranged between 18 pg/m^ to 33 ug/m^. None of the measurements were above the NPAAQS of 65 pg/m^ 24-hour average concentration of particulate matter 2.5 micrometers or less in aerodynamic diameter. The average PMg,5 concentration for the entire school building was approximately 29 pg/m3. The PM2.5 average concentration was below the USEPA recommended concentration of 40 pg/m^ for sensitive

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