The purpose of this study was to assess worker and community exposure to
bioaerosols emitted from a suburban yard waste composting facility in northern
Illinois, USA. Characterization of on- and off-site viable bioaerosols was
undertaken through a total of 288 on- and off-site Andersen samples conducted
over 10 sampling days. A total of 46 dust samples and 38 Kramer-Collins spore
samples were also collected in this period. Evaluation of the impact of the
facility on community bioaerosol concentrations was undertaken by comparing on-
and off-site measurements by sampling locations, wind direction, and site
activity. On-site concentrations of total spores, Aspergillus/Penicillium
spores, total bacteria, Gram-positive bacteria, Gram-negative bacteria,
actinomycetes, total particulates, endotoxin, and ß-1,3 glucans were higher than
off-site concentrations. Total fungal spores averaged 13,451
spores/m³ (range 5,223-26,067) on-site and 8,772 spores/m³
(range 243-18,276) off-site. Viable bacterial airborne concentrations (in
cfu/m³) averaged 11,879 on-site (range 480-78,880) and 3,204 off-site
(range 160-17,600). Mean levels of endotoxins (in ng/m³) were 1.94
on-site (range 0.12-6.06) and 0.14 off-site (range 0.01-0.41). Mean levels of
ß-1,3 glucans (in ng/m³) were 2.17 on-site (range 0.12-14.45) and
0.24 off-site (range 0.01-0.78). Mean total viable fungi, on the other hand,
were higher off-site than on-site (8,651 vs 3,068 cfu/m³). On-site
concentrations of total bacteria, Gram-positive bacteria, Gram-negative
bacteria, and actinomycetes demonstrated a statistically significant pattern of
decreasing concentration with distance from pile and higher downwind vs upwind
concentrations. Mean on-site concentrations of viable bacteria, viable fungi,
and endotoxins were significantly higher during periods of activity compared to
periods of no activity. Off-site concentrations of bacteria were also
significantly higher during periods of activity compared to no activity. The
highest concentrations of total particulates, endotoxin, and ß-1,3-glucans were
observed in the personal samplers worn by workers at the facility. One personal
sampler measured an Asp f1 exposure of 22.17 ng/m³ during turning
activity. Peak exposures to several bioaerosol constituents were sufficiently
high to warrant use of respirators by workers during periods of pile activity
that lead to dust generation.