VOC sampling locations table for Ground Zero area, Jan 2002

NYC 9/11 Public Portal Document

. » - - information about the toxicity and mode of action of WTC PM2.5. Since there was not enough PM2S or PMjs.io sample available to conduct an inhalation exposure study (> 2 g necessary), it was decided to use a PM53 sample (sieved but not further fractionated) which was available in large enough quantities to run through the inhalation exposure system. The EPA inhalation exposure system has a 2.5 pm cut-point cyclone to remove larger particles (Ledbetter et al., 1998), and therefore measurement of the PM concentration in the exposure zone of the chamber represents exposure to PM2.5. A sample of PM53 from A liBl location #3 (figure 1), 0.3 miles east of Ground Zero (in Figure 2. WTC bulk dust samples were size-fractionated by the predominant wind direction), was available in large NYU. Filters containing the PM2.5 fraction were received at the enough quantities for the nose-only inhalation exposure U.S. EPA in Research Triangle Park, NC on 10/26/2001, and study. This sample was sent by overnight express from were inspected and photographed 10/29/2001. NYU and received on November 21,2001.

were collected, filters containing the PM2.5 fraction were B. Extraction of PM from Teflon Filters selected from seven locations (sites 8,11,13, B, C, E, and Filters were extracted using a modification of a F) around Ground Zero, in order to assess toxicity of method by Biran and coworkers (1996). Each filter was samples from different geographical locations as well as handled with clean sterilized stainless steel forceps. overall toxicity of a pooled sample from these locations Filters from each of the 7 individual collection sites (1-3 (Figure 1). The locations were selected to represent a filters per site) were extracted into a single volume of distribution surrounding the WTC site, with more distilled water (Gibco BRL ultrapure 10977-015, lot collection sites in the east reflecting the predominant 1063705) in the ratio of 0.5 ml water per mg sample (2 mg winds in that direction. PM / ml water; range 24.96 - 27.14 ml). This volume of Fourteen Teflon filters containing the PM2 5 fraction water was pipetted into a 100 ml sterile plastic specimen from the 7 different sites collected around the World cup containing a 3 mm thick Teflon ring at the bottom of Trade Center on 9/12/01 and 9/13/01 were shipped by the cup designed to support the filter. Filters were wetted overnight express to EPA and received on October 26, with 200 pl of 70% ethanol on the particle side. The 2001, and these were inspected and photographed on liquid was gently spread on the filter with the pipet tip, October 29, 2001 (Figure 2). [Throughout the WTC2001 taking care not to scrape the filter. The filter was then study, sample transfers were accompanied by signed placed on top of the 3 mm thick Teflon ring in the chain-of-custody letters]. A total quantity of about 50 mg specimen cup with the particle side down, and a 6 mm from each site, collected on 1 to 3 filters per site, was thick Teflon ring was placed on top of the filter. The cup provided. The weight of PM2.5 on the filters was with the filter was secured to an orbital shaker (Titer Plate determined by NYU, and was separately determined at Shaker, Lab-Line Instruments, Melrose Park, IL). A EPA after overnight dessication using a Cahn cleaned sonicator probe (18 mm diameter. Sonic 300 electrobalance. The description of the locations of the 7 Dismembrator, Artek Systems Corp., Farmingdale, NY) samples and the total weight of PM2.5 on the filters from was rinsed with 1% Triton X-100 (Sigma Chemical Co., each site is provided in Table 1. PM25 could not be St. Louis MO; T8787), and then ultrapure distilled water efficiently scraped off of one filter, so it was necessary to (Gibco BRL ultrapure 10977-015, lot 1063705) before and isolate the PM2 5 using an aqueous extraction procedure after each extraction. The probe was then lowered into the (see below). water in the specimen cup to a level just above the filter. Throat irritation, cough, nosebleeds, and other mucous Ice was placed around the specimen cup to prevent rising tissue/sensory irritation were reported by residents and temperatures during sonication, and the temperature ofthe workers in the WTC area (Washington Post, 2002). water was measured before and after sonication. The Oropharyngeal aspiration of PM bypasses the nose and shaker was turned to the lowest speed at which it would therefore potentially relevant effects may go undetected. run continuously (setting = 2). The sonicator power was Consequently, it was decided that an inhalation exposure set to 30, and the filter was sonicated for 30 minutes while study should be conducted which might reveal important rotating on the orbital shaker. After sonication, the filter

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