Letter regarding air quality monitoring results, 111 Broadway, Feb 2002

NYC 9/11 Public Portal Document

AKRF,Inc. 111-115 Broadway,New York,New York

3.0 CONCLUSIONS Based on the results of this indoor air quality investigation, AKRF presents the following conclusions: • Levels of polynuclear aromatic hydrocarbons (PAHs), metals, asbestos, respirable particulate, silica, and volatile organic compounds (VOCs) were all ob'ser'ved to be below regulatory and recommended guidelines. • Levels of formaldehyde were observed to be well below OSHA regulatory requirements. Eight samples were observed to be above the NIOSH recommended exposure level. All other levels of aldehydes were observed to be below regulatory and recommended guidelines. • Levels of dioxins above the analytical detection level were identified within one sample. All other samples revealed no detectable levels of dioxins. No regulatory limit exists for occupational exposure to dioxins. NIOSH has recommended, absent other guidelines, that levels of dioxins be reduced to the lowest feasible concentration. • Relative humidity, carbon dioxide and carbon monoxide levels were all observed to be within established ASHRAE guidelines. Some temperature readings throughout both buildings were observed to be above the ASHRAE guidelines for wintertime conditions. Because the sampling was conducted within unoccupied spaces, temperature variations may be due to the building's systems settings.

4.0 RECOMMENDATIONS Based upon the conclusions of this indoor air quality investigation, no specific recommendations are presented at this time. However, because of the continuing concerns of people occupying the downtown area along with the continuing press coverage, Rosenman & Colin LLP may wish to consider additional indoor air quality monitoring. Should this monitoring be performed, AKRF suggests that this monitoring include temperature, relative humidity, carbon dioxide, carbon monoxide, respirable dust and asbestos sampling. In addition, mercury should be sampled, for in both the dust and fume forms. To alleviate any possible concerns with formaldehyde, sampling in the affected spaces could be conducted with the ventilation system in operation, as it would be with full occupancy. Sampling could also be conducted on occupied floors, representative of the building's spaces. Similarly, additional dioxin sampling could be conducted to provide additional data in relation to the single air sample that revealed detectable levels of dioxins.

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NYC-WTC 000105630