Indoor Air Quality Report, P.S. 150M, April 2002

NYC 9/11 Public Portal Document

Mr. Bernard P. Orlan April 12, 2002 Indoor Air Quality Assessment Page 3 P. S. 150M ATC Project No. 15-19125-0289

Real-Time Environmental Measurements

ATC collected forty (40) sets of real-time environmental measurements consisting of thirty (30) 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 12:00 P.M. and concluded at approximately 1:30 P.M.

Temperature

Indoor dry bulb temperature measurements ranged from 67.8°F to 75.4°F. One (1) of the measurements was below and five (5) 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 58.1°F to 60.0°F.

Relative Humidity

The relative humidity indoors ranged from 28.0 to 39.7 percent. Five (5) of the measurements were below the ASHRAE-recommended range of 30 to 60 percent for occupant comfort. The outdoor relative humidity measurements ranged from 30.0 to 31.3 percent.

CaHronDioxideConcentration

Carbon dioxide concentrations indoors ranged from 558 ppm to 1120 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 479 ppm. Therefore, the maximum acceptable level of CO2 at this location was 1179 ppm (background level -1- 700 ppm). 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.

Carbon Monoxide Concentration

Carbon monoxide indoor concentrations ranged from 1 ppm to 2 ppm. These concentrations were below the NPAAQS/ASHRAE guideline of 9 ppm. The outdoor CO concentration was 1 ppm for all collected readings.

Respirable Particulates (PM2_5) ppm.

Respirable particulate concentrations* indoors ranged between 12 pg/m^ to 27 pg/m^. None of the measurements were above the NPAAQS of 65 pg/m or above the USEPA recommendation of 40 pg/m^ for sensitive individuals and children. The average PM2.5 concentration for the entire school building was approximately 21 pg/m^. The PM2.5 average concentration was below the USEPA recommended concentration of 40 pg/m^ for sensitive individuals and children. The outdoor respirable particulate concentration measurements ranged from 27 to 32 pg/m^ with an average of 30 pg/m^.

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