Artificial and Biological Particles in the Springtime Atmosphere.

This study focused on a comprehensive and detailed interpretation for the springtime air quality influenced by both artificial (particulate matter (PM) and asbestos) and biological (pollen) sources in Fukuoka Prefecture, Japan. An intensive measurement of PM was conducted at four characteristic sites (i.e., a heavy traffic area, a residential area, an industrial area, and a desolate area) in the Fukuoka Prefecture during spring of 2007. Analysis of major ionic species in PM_2.5 was performed by an Ion Chromatography, and asbestos and pollen were identified by Scanning Electron Microscopy with an energy dispersive X-ray spectrometer (EDX). PM_2.5 concentration (65.3 µg m^-3) measured in an industrial area (site C) was extraordinarily high compared to those monitored in other areas; it greatly exceeded the Japan's PM_2.5 criteria (a daily average of 35 µg m ). NOAA's HYSPLIT dispersion model suggests that this high level of PM_2.5 monitored at site C is unlikely to affect the Asian continent. The ambient concentrations of PM_2.5-related anions (NH₄ ⁺, NO₃ ^-, and SO₄ ²⁺) and their relative contributions to PM_2.5 were also investigated in four study areas. The concentrations of these major water-soluble ions exhibit not only strong spatial dependence but also different ratios to each other. Asbestos fiber (crocidolite and amosite) concentration values changed in the range of 2.5 to 14.4 f per liter of air. The number of pollen grains showed that Cedar ranked higher in concentration than other types of pollen, with the maximum concentration at site A. [ABSTRACT FROM AUTHOR]