Abstracts: ISEE 22nd Annual Conference, Seoul, Korea, 28 August-1 September 2010: Air Pollution - Exposure Characterization and Health Effects
1Istituto Nazionale Tumori, Milan, Italy; 2SIMG, Milan, Italy; 3OFT, Paris, France; 4Research Institute for a Tobacco Free Society, Dublin, Ireland; 5Universidade do Minho, Braga, Portugal; 6Agencia de Salut Publica, Barcelona, Spain; and 7Medical University, Wien, Austria.
Abstracts published in Epidemiology have been reviewed by the societies at whose meetings the abstracts have been accepted for presentation. These abstracts have not undergone review by the Editorial Board of Epidemiology.
Better knowledge of particulate matter concentrations needs portable, reliable, user friendly, low cost, real time mass analyzers of particulate matter (PM2.5) and PM10. Optical particle counters (OPC) measuring mass have manufacturer calibration specific gravity “K” factor referred to polystyrene latex particles, which are completely different than those of the real world; therefore, they require specific calibrations. Measurements are also subject to relative humidity (RH) heavy interference. The aim of this study is to evaluate, within the Impact of Smoke-free Policies in Eu Member States WP2 Project, the performance of 4 different OPC's in environmental tobacco smoke and background urban pollution and to find the new “K” factors using 1 Model BAM-1020 with certificate number EPQM-0798-122 for comparison.
All instruments have been operating in parallel measuring PM2.5 generated by cigarettes (ETS) indoor and by urban pollution outdoor, and the data were replicated 3 times.
“K” factors were widely different between manufacturer's model, instrument serial numbers, ETS, and urban pollution, ranging from 0.5 to 2.27. Correlation with BAM-1020 was ranging from 0.7500 to 0.9800 and Student t test from 0.3000 to 0.9500. RH interference resulted mathematically compensable up to 75% RH, but above becomes uncontrollable and sample drying becomes compulsory.
OPCs are very reliable and accurate, but need specific calibration and special care in handling and elaboration of the measurements.