Bioaerosols - Aerosols: Measurement, Dosimetry, and Health Effects - page 327

been determined, for example, cellulose, wood dust, cotton dust, grain dust, nicotine, pyrethrum,
starch, subtilisins, sucrose, turpentine, and vegetable oil mist. 201 Better human exposure-response
data and information from animal models eventually may lead to the establishment of numeric
exposure limits for more biological agents. Nevertheless, avoidance of indoor dampness and prompt
removal of contaminated materials provide better protection from indoor mold than would adher-
ence to air concentration limits, and selection of less allergenic plants for landscaping projects
would help protect persons hypersensitive to those pollen.
The ields of aerobiology and bioaerosol research would advance more rapidly if it were conve-
nient to measure personal exposure and inhaled dose over extended time periods rather than to esti-
mate exposures from the concentration of biological agents in settled dust or small-volume, grab air
samples collected with stationary samplers. The continued development and wider availability of
rapid methods not based on microbial cell multiplication or visual particle recognition will provide
better exposure information. It is not clear to what level microorganisms and pollen grains need to
be identiied (e.g., class, family, genus, or species) to understand dose-response relationships nor
to what extent measurements of marker compounds can be used for risk assessment (e.g., glucan
or ergosterol for fungi and muramic acid or fatty acids for bacteria). Therefore, we look forward
to wider availability of methods that measure exposure to biologically active agents rather than
surrogates.
Continued research is needed to gain a clearer understanding of the positive and negative effects
of exposure to biological agents at different ages and stages of lung development, and more effort
should be made to understand the mechanisms of bioaerosol action and fate in the respiratory tract.
Particles of biological origin account for substantial fractions of airborne PM, and the interactions
of bioaerosol and other air pollutants deserve greater attention.
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