NYC-WTC_000199261

NYC 9/11 Public Portal Document

Mr. Bernard P. Orlan August 28, 2002 Indoor Air Quality Assessment Page 4 J.H.S. 131 M ATC Project No. 15-19125-0346

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

TVOC Concentration

The TVOCs indoor cor centrations ranged from 0.1 to 0.2 ppm. These concentrations were below the AIHA guideline for odor control of 1 ppm. The outdoor TVOC concentration was 0 ppm.

OBSERVATIONS

During this assessment ATC noted the following: • ITie interior of the building appeared clean and free of dust and debris; • The building was not occupied at the time of the assessment; • No smoke odor was detected in the building;

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

1. Concentrations of C'O and TVOCs were within applicable standards and guidelines. 2. Forty (40) of the indoor measurements were above the range of 73 to79 °F (at 50 percent relative humidity) recommended by ASHRAF Standard 55-1992 during the summer season. 3. All of the indocr measurements for relative humidity were within the ASHRAE- recommended range of 30 to 60 percent for occupant comfort. 4. Two (2) of the indoor measurements for CO2 were above the ASHRAE Standard 62-1999 recommended maximum concentration of <700 ppm above the background level. The highest reading was measured in the basement office with 9 occupants at 2:46 PM. Carbon dioxide measurements are used as an indicator of available outdoor air. The primary source of CO2 indoors is occupant respiration. 5. Two (2) of the indoor measurements for PM2.5 were above the NPAAQS of 65 pg/m^ 24- hour average concentration of particulate matter 2.5 micrometers or less in aerodynamic diameter. Eight (8) of the forty-seven (47) instantaneous indoor readings were above the USEPA recommended concentration of 40 pg/m^ for sensitive individuals such as asthmatic people and children. All of the outdoor measurements for PM2.5 were below 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/m^ for sensitive individuals such as asthmatic people and children.

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NYC-WTC_000199264