Results from a small number of cascade impactor air samples indicated that approximately 90% of total particle mass and arsenic was present in particle size fractions >/= 3.5 micron.
Integrated samples of PM2.5 mass also were collected using a Harvard Impactor (Air Diagnostics and Engineering Inc., Harrison, ME) for daily calibration of the trip and facility periods.
PM2.5 concentrations were measured using Tapered Element Oscillating Microbalance (model 1400A; Rupprecht & Pasternack, Albany, NY) operated at 50°C with a PM2.5 impactor (Air Diagnostics, Harrison, ME) with two plates.
Limitation of the traffic in the OR Microbiological air counts will be measured using an impactor air sampler (Air-test Omega, LCB, La Salle France) at a flow rate of 100 L/min for 5 min (500 L) sampling on to Trypticase soy agar (BioMerieux, France), which will then be incubated for 4 days at 30°C.
Harvard-Marple impactors (Air Diagnostics, Harrison, ME) collected PM2.5 and PM10 samples at 10 and 4 L/min, respectively.
At residences, 24-hr integrated samples were collected with Harvard-type PM10 impactors (Air Diagnostics and Engineering, Inc., Harrison, ME) at 10 L/min flow rate in a multileg sampler.
Fine particles [particulate matter with aerodynamic diameter ≤ 2.5 μm (PM2.5)] were collected with Harvard impactors (Air Diagnostics and Engineering, Harrison, ME, USA), nitrogen dioxide was collected by Palmes tubes, and light-absorbing carbon was measured as the reflectance of the PM2.5 filters, a method shown to be highly correlated with thermal elemental carbon measurement (Cyrys et al. 2003).
PM2.5 concentration was measured using Harvard impactors (Air Diagnostics and Engineering Inc., Naples, ME, USA); PM2.5 absorbance was assessed from the reflectance of the particulate filters by M43D Smoke Stain Reflectometer (Diffusion Systems Ltd., Hanwell, UK) (Hoek et al. 2002), and NO2 concentrations by Palmes tubes (Cyrys et al. 2000).
Hirsttype volumetric slit impactors (continuous recording air sampler for glass slides, model 9100; Burkard Manufacturing Co. Ltd., Rickmansworth, UK) measured indoor and outdoor spore concentrations (Hirst 1952).
When the elliptical concave impaction plates with the A/B ratio of 4.0 and 3.5 were applied to the MST indoor air sampling impactor having PM10 and PM2.5 stages, the cut-off size was predicted to decrease from 10to6.5.5 μm and from 2.5 to 1.6 μm, respectively, while the impactor collection efficiency curves became less steep.
For ambient monitoring, a portable, self-contained weather station near a high-volume air particle impactor and the ambient air samplers was used to monitor the air temperature, relative humidity, wind speed, and direction, as described previously (Cheng et al. 2005a, 2005b, 2005c; Naar et al. 2002; Pierce et al. 2003).
