The health effects of particulate air pollution are of growing interest to scientists and public health researchers. The main concern is with particulate matter (PM) with an aerodynamic diameter of less than 10 µm (PM10), and especially with those with aerodynamic diameter under 2.5 µm (PM2.5), because of their ability to penetrate deep into the lung. These fine particles are linked to increased amounts and severity of some respiratory diseases. Measurement of the PM is necessary in order to study its relationship to certain health effects, and this is usually accomplished by collecting samples with an air filter. The purpose of this investigation is to see if it is possible to sample particulate air pollution using leaves in place of the filters. Leaves have been shown to collect pollutant particles. If accurate, leaf sampling would have many advantages: they do not need to be manually set up, no expensive sampling equipment is required, samples are naturally available in many locations, they can collect particles for a longer period of time than filter samples, and they may show a reaction to some types of materials.

The idea of using leaves to indicate the presence of air pollution is not new. The idea has been proposed for study of certain types of gaseous air pollution. However, the idea of using leaves for the study of particulate air pollution is new, and is the subject of growing interest.

This investigation was conducted in two phases, as part of ongoing research into particulate matter in the Environmental and Occupational Pathology Division at SUNY Upstate Medical University. Since the completion of Phase I, a study using similar methodology has been published. However, this study, by D.L. Johnson et al, examined the ability of leaves to remove particles from the air rather than their possible use as a method of measuring particulate air pollution. Studies of particles on leaves were conducted by others before Phase I of my investigation, however they used mainly washing techniques to remove the particles from the leaves and onto filters for easier study. However, washing may not remove all particles from the leaves, or may leave certain types of particles on the leaf, which may affect the final elemental, size, and/or concentration data.