Air sampling report, M833 school, February 2002

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Mr. Bernard P. Orlan March 6, 2002 Air Sampling for Formaldehyde & Ozone Page 3 H. S of Economics & Finance (833M) ATC Project No. 15-19125-0291

OSHA has a Permissible Exposure Limit (PEL) for NO2 of 1 ppm (ceiling concentration, not to be exceeded in 8 hours) and a PEL for NO of 25 ppm (8-hour time-weighted average). These are occupational standards and are not generally applicable to indoor air quality in schools. The federal and New York State ambient air quality standard for NO2 is 0.05 ppm (12-month average), there is no standard for NO.

These results are from short-term (4-hour) samples and cannot be directly compared to the ambient air standard which is averaged over a full year. Results for both NO2 and NO were well below the OSHA PELs. Oxides of nitrogen from various combustion sources are the main source of the ozone that creates the smog mentioned above. The presence of oxides of nitrogen in ambient air is not unexpected.

Sulfur Dioxide (SOj

SO2 was detected in both samples and in the blank. The concentration in the blank exceeded that of the outdoor sample. The results are shown in Table 3:

TABLE 3 SO2 Concentrations February 23, 2002 SO2 SO2 Cone. SOjConc. Sample Location per sample Vol. SO2 Cone, Blank- Blank- Sample No. (micrograms) (liters) (mg/m’= corrected corrected ppm) (mg/m’) (ppm) Outdoors by Main 12.8 200 0.0640= BDL BDL entrance / SO-01 0.0244 U Floor by elevators 20.7 200 0.104= 0.022 0.008 / SO-02 0.0395 Blank/SO-03 16.3

OSHA has a Permissible Exposure Limit (PEL) for SO2 of 5 ppm (8-hour time-weighted average). This is an occupational standard and is not generally applicable to indoor air quality in schools. The federal and New York State ambient air quality standard for SO2 is 0.03 ppm (12- month average).

These results are from short-term (3-hour) samples and cannot be directly compared to the ambient air standard which is averaged over a full year. Results for SO2 were well below the OSHA PEL. SO2 is a common pollutant in urban air, much of the SO2 in air on the East Coast of the United States is attributed to emissions from coal-burning power plants in the Midwest. The presence of oxides of SO2 in ambient air is not unexpected.

Conclusion

Based on the results of the air sampling described above, ATC concludes that there is no significant exposure to these substances at the locations tested. Additional sampling does not appear necessary.

CONFIDENTIAL, CITY_21MC1OO_OO3463217 SUBJECT TO PROTECTIVE ORDER NO. 2, SEPT, 2008

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