Indoor Air Quality Report, March 8, 2002, NYC School

NYC 9/11 Public Portal Document

Mr. Bernard P. Orlan March 11,2002 Indoor Air Quality Assessment Page 3 H.S. of Economics and Finance (M833)________ ATC Project No. 15-19125-0291 Reai -Time Environmental Measurements

ATC collected one hundred (100) sets of real-time environmental measurements consisting of eighty-eight (88) in the school building and twelve (12) outdoors. Field data sheets are found in the Attachment. Readings began at 8:45 A.M. and concluded after 2:40 P.M. The results are described below.

Temperature

Indoor dry bulb temperature measurements ranged from 58.6 °F to 72.7 °F. Twenty eight (28) of the indoor measurements were below and sixty (60) were within the range of 68 to 75°F (at 50 percent relative humidity) recommended by ASHRAE Standard 55-1992 during the heating season (wintertime conditions). The outdoor temperature ranged from 41.4 to54.3 °F.

Relative Humidity

The relative humidity indoors ranged from 32.8 percent to 52.6 percent. All eighty-eight (88) measurements were within the ASHRAE-recommended range of 30 to 60 percent for occupant comfort. Eighty-eight (88) measurements were within the ASHRAE recommended range. The outdoor relative humidity ranged from 38.4 to 61.8 percent.

Carbon Dioxide Concentration

Carbon dioxide concentrations indoors ranged from 364 ppm to 1655 ppm. Eighty-six (86) of the indoor measurements were below the ASHRAE Standard 62-1999 recommended maximum concentration of <700 ppm above the background level. The outdoor (background) CO2 concentration was 442 ppm. Therefore, the maximum acceptable level of CO2 at this location was 1142 ppm (background level + 700 ppm). The highest reading (1655 ppm) was measured in basement hallway outside Gym approximately at 10:10 AM. Please note that hallway was occupied by approximately 24 people involved in exercise activity. Levels above the recommended maximum do not indicate a health risk. Carbon dioxide measurements are used as an indicator of available outdoor air. The primary source of CO2 indoors is occupant respiration.

Carbon Monoxide Concentration

Carbon monoxide concentrations indoors were 1 to 7 ppm. These concentrations were below the NPAAQS/ASHRAE guideline of 9 ppm. The outdoor CO concentration ranged from 1 to 7 ppm.

Respirable Particulates (PM2,5)

Respirable particulate concentrations* indoors ranged between 15 pg/m^ to 62 pg/m^ with an average 8 pg/m^- None of the instantaneous 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 indoor PM2.5 average concentration was 27 pg/m^ also below the USEPA recommended concentration of 40 pg/m^ for sensitive individuals / children. The outdoor respirable particulate concentration ranged from 100 pg/m^ to 150 pg/m^ with an average of 126 pg/m^. All of the measurements were above the NPAAQS of 65 pg/m^ (24-hour average) and the USEPA recommended concentration of 40 pg/m3 for sensitive individuals /' children.

CONFIDENTIAL, CITY_21MC100_003461969 SUBJECT TO PROTECTIVE ORDER NO. 2, SEPT. 2008

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