Measuring reflectance of TSP-filters for retrospective health studies

We measured the reflectance of 174 TSP filters from an air quality study to determine whether the blackness of the filters (an indication of incomplet e combustion) could be used as an additional measure of particulate air pol lution in retrospective health studies. It is important in health studies t o differentiate soil-derived coarse particles from combustion-derived parti cles, Reflectance was measured with a monochromatic reflectometer and absor ption coefficients were derived from the reflectance values using the ISO f ormula for black smoke absorption coefficients. In the urban setting, the a bsorption coefficients for TSP filters were associated with black carbon (r = 0.89), black smoke absorption coefficients (r = 0.9), and gaseous, traff ic-related pollutants (r for NO2 = 0.84), which were measured recently at t he same location. Measuring the reflectance of TSP filters is a useful meth od to estimate the relative concentration of combustion-derived particulate matter in a subarctic winter climate. This method could be useful in retro spective health studies. (C) 2000 Elsevier Science Ltd. All rights reserved .