Real-time air monitoring report, PS 234M, Dec 2001

NYC 9/11 Public Portal Document

Mr. Bernard P. Orlan Januaiy' 11, 2002 Real-Time Air Monitoring Page 4 P.S. 234 (Manhattan) ATCPrpiectNpJ5O912S:0279

Only one indoor reading, recorded in Room 315 on the afternoon of December 8^^, exceeded the value of the EPA ambient-air quality standard of 65 ug/m^. It bears repeating that the standard is a 24-hour average and the measured level is an instantaneous reading. All other indoor readings were below 65 ug/m^.

Nitrogen Dioxide CNQ-)) Table 3 summarizes the NO2 data for each day. As with the particulate data displayed above, the indoor levels were consistent with outdoor levels.

TABLES NO2 LEVELS PARTS PER MILLION (ppm) . A TA.. , . ' D ATE :}LQCATIGN;' AVERAGE HIGH LOW <5'» ■■■ J It W It"" ; ■'A

Indoors 02 0.6 0^0 Dec. 8 Outdoors 0.2 0.6 0.0

Indoors 0.1 0.4 0.0 Dec. 9 Outdoors 0.2 0.6 0.0

Indoors 0.2 0.6 0.1 Dec. 10 Outdoors 0.3 0.6 0.0

Indoors 0.3 0.6 0.0 Dec. 12 Outdoors 0.4 0.7 0.1

Eleven of forty-four indoor readings were 0.0 ppm, all other indoor readings were 0.1 - 0.6 ppm. The EPA ambient-air quality standard of 0.053 ppm is an annual average. The same is true of the New York State standard of 0.05 ppm (100 ug/m^). The measurements summanzed in the table are instantaneous readings. A direct correlation between these readings and the standards cannot be made.

Other Parameters

NO, SO2, H2S and TVOC were not detected on any of the four days.

FINDINGS

Based on the visual inspection of the occupied spaces and real-time measurements, the following findings are presented:

1. Measurements of concentrations of temperature, relative humidity, CO2 and CO were within recommended guideline ranges (building unoccupied);

CONFIDENTIAL, CITY_21MC100_003444798 SUBJECT TO PROTECTIVE ORDER NO. 2, SEPT. 2008

NYC-WTC_000177890