NYC-WTC_000219378

NYC 9/11 Public Portal Document

Mr. Bernard P. Orlan April 9, 2002 Indoor Air Quality Assessment Page 4 H.S. of Economics and Finance (MESS') ATCProiectNoM5-19125-0291 aerodynamic diameter. Six of the (6) of the nine (9) instantaneous outdoor reading were above the USEPA recommended concentration of 40 pg/m^ for sensitive individuals and children.

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

TVOC Concentration

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: o The interior of the building appeared clean and free of dust and debris; o The building was occupied at the time of the assessment; o No smoke odor was detected in the building;

FmraNGS

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

1. Concentrations CO and TVOCs were below applicable standards and guidelines. 2. Six (6) of the indoor measurements for temperature were below, eleven (11) measurements were above, and seventy-one (71) measurements 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). 3. Six (6) of the indoor measurements for relative humidity were below and eighty-two (82) were within the ASHRAE recommended range of 30 to 60 percent for occupant comfort. 4. Five (5) 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 level was measured in the cafeteria at 11:47AM with 200 occupants. 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. 5. All of the indoor measurements 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 and children. Three (3) of the outdoor measurements was above the NPAAQS of 65 pg/m^ 24-hour average concentration of particulate matter 2.5 micrometers or less in aerodynamic diameter. Six of the (6) of the nine (9) instantaneous outdoor reading were above the USEPA recommended concentration of 40 pg/m^ for sensitive individuals and children.

CITY_2IMC10 0_0 0 2 8 7 9 7 6 2

NYC-WTC_000219381