NYCDOH/ATSDR residential asbestos sampling results, April 2002

z z o o co § c o o 155 • Compare results to representative background.** • Identify meteorological conditions and factors such as • Compare results to representative background.** • Review pre-sampling questionnaire responses. m c CT o' o> road traffic during sampling. • Evaluate multiple source contributions (WTC, m cn o o o • Use for evaluation of outdoor contribution to indoor outdoor, indoor activities cooking ^cleaning,..). 3. 03 Ca3 concentrations • Assess ventilation systems (heating and cooling). o o • Compare to DEC monitors • Recommend proper clean-up techniques be employed. o c • Consider re-sampling and evaluate nearby 3 residences/common areas. CD

Inhalable Particulate 24 hour TSP

• Compare results to representative background.** • Compare results to representative background.** 250 • Identify meteorologic conditions, activities such as • Assess ventilation systems (heating and cooling). road traffic or construction activities during sampling. • Consider evaluating with modification to occupational • Assess the need for dust suppression procedures. standards. • Recommend proper clean-up techniques be employed. • Consider re-sampling after clean-up has occurred.

--------------------------------------------------------------------------------------- — _ --- ------------- — ---------------- _ - ------------------------------------------------------------ ** As sampled in “Ambient and Indoor Sampling for Public Health Evaluations of Residential Areas Near WTC.” * National Ambient Air Quality Standard (NAAQS) 2 Total Suspended Particulates, New York State Ambient Air Quality Standard ’ The range of ratios reported in the 1996 and 2001 draft Ambient Air Criteria Documents for Indoor and Outdoor concentrations of PM 2.5 could be used to select a multiplier to be applied to the area level of concern. While estimates (from a limited number of studies) range from slightly less than one, to two (higher if smoking

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