VOC sampling locations table for Ground Zero area, Jan 2002

NYC 9/11 Public Portal Document

before and after weighing samples each day (Class U The aerosol was generated using a unique exposure system calibrated weights, Denver Instrument Company, Arvada, which conserves sample by using a carpenter’s chalk line CO). PM samples were allowed to come to room to pick up particles from a small Tygon tube dust reservoir temperature from 4 °C before weighing. Sterile 2.5 ml (illustrated in Ledbetter et al., 1998). The dust is carried glass vials or 5 ml polystyrene snap cap vials were used to out through an orifice and blown off the string in a weigh and resuspend PM samples. Vials weights were discharge head with a high velocity air jet. The particles tared, and a sterilized stainless steel spatula was used to are carried through a particle charge neutralizer and 2.5 p transfer sample to the weighing vial, and the sample was cut-point cyclone to remove particles larger than PM2.5, weighed. The sample was then resuspended with sterile and finally enter the inlet of the nose-only chamber. saline (Sigma S-8776 single use vials, lot 128H2310) Nose-only exposure tubes-were constructed from 50 using a calibrated Rainin Pipetman at a concentration of 2 ml polypropylene centrifuge tubes with the bottom end mg/ml. All mice aspirated a volume of 50 pl. Samples removed. Mice were randomized into exposure groups as were vortexed and used straight (100 pg dose) or diluted described above, and 49 in each group were placed in as necessary (to 0.632 mg/ml or 0.2 mg/ml for 31.6 pg or exposure tubes (1 extra per group in case any mice died 10 pg doses, respectively). All samples were sonicated for during the exposure). Mice were not acclimated to the 2-4 minutes at 22 °C (Branson model 3210R-DTH, tubes prior to exposure, since stress may be an important Danbury, CT) prior to oropharyngeal aspiration. component of the response to WTC PM. In order to Mice randomized into different exposure groups were measure immediate airway responses to air or WTC3 anesthetized in a 2.7 L plexiglass chamber by passing sample and also to handle the large number of mice, the house air through an aerator containing methoxyflurane control air exposure was begim 1 hour before the WTC3 (Metofane; Mallinckrodt, Mundelein, IL). The vapor exposure. induced rapid anesthesia, at which time the mouse was Dust concentration was determined gravimetrically on taken out of the chamber and placed on an aspiration 5 Teflon filters (45 mm diameter with 1 ppore size) taken platform. The tongue was gently pulled back and held at a sample flow rate of approximately 0.24 L/min. The with a forceps, and 50 pl of PM suspension or saline alone filters were weighed just prior to and after sampling using was pipetted in the back of oropharyngeal region using a a Cahn C-30 balance housed in a controlled temperature 200 pl tip. The tongue was held until the animal was and humidity enclosure. Real-time PM concentration was forced to aspirate the sample, and placed back in its cage. achieved with an aerosol monitor (Dust Track, TSI Inc., Mice recovered within .5 or 10 minutes of this procedure. St. Paul, MN) on the chamber exhaust. The particle size This technique is equivalent to intratracheal instillation in was determined gravimetrically using a Mercer Cascade deposition efficiency (Foster et al., 2001), and several Impactor (Intox Products, Albuquerque, NM). On publications describe experiments in which it was November 29, 2001, the exposure system was restarted successfully used (e.g. Dreher et al., 1997, Gavett et al., and 7 Teflon and 3 polycarbonate filters were taken for 1999, Kodavanti et al., 1998). chemical analysis. On December 17, 2001, 18 polycarbonate filters (9 WTC3 and 9 blanks) were I. Nose-Only Inhalation Exposure. collected for chemical analysis and 3 quartz filters were In order to assess the effects of WTC PM2.5 on upper collected for carbon analysis. respiratory tract responses, mice were exposed to WTC3 or air only in two separate nose-only inhalation exposure J. Respiratory Responses Assessed by Whole Body chambers. The exposures were conducted for 5 hours in Plethysmography. 52-port nose-only flow-by inhalation chambers (Lab 1. Immediate Airway Responses to PM2 ; Exposure. Products) on November 27,2001. The exposure time was Exposure to PM2 5 by oropharyngeal aspiration or by based on practical considerations of the tasks involved on inhalation may result in immediate changes in breathing the exposure day. The WTC3 sample was a tan powder parameters. Breathing parameters in unanesthetized received in a plastic jar, and was desiccated at room unrestrained mice were assessed in a 12-chamber whole temperature prior to use. Preliminary exposures were body plethysmograph system (Buxco Electronics, Sharon, conducted on several days prior to exposure to set CT). The animal chambers have a pneumotach on the roof exposure parameters, which indicated that an aerosol to measure pressure (which is proportional to air flow) concentration of 10-15 mg/m’ could be achieved. The relative to the pressure in a reference chamber vented to control chamber and the WTC3 chamber had similar flow the atmosphere. The breath by breath signals are taken by rates (~ 12 L/min) and received air from the same source. the program software to compute respiratory rate

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