Ten samples of stored wheat grain and 10 samples of settled grain dust released
during machine threshing of wheat grain were collected on 10 farms located in
Lublin province (eastern Poland). The samples were examined for the
concentration of total microfungi, Fusarium species, fusariotoxins
(moniliformin, deoxynivalenol, nivalenol), and ochratoxin. Microfungi able to
grow on malt agar were present in 30% of grain samples (median for all examined
samples = 0, range 0-227.5 × 10³ cfu/g) and in all samples of grain
dust (median = 977.5 × 10³ cfu/g, range 115.0-16,700.0 ×
10³ cfu/g). Fusarium species (F. avenaceum) were found only in 10% of
grain samples (median = 0, range 0-800.0 × 10³ cfu/g), but in 90% of
grain dust samples (median = 1,150 × 10³ cfu/g, range 5.5-10,060.0 ×
10³ cfu/g). The species F. avenaceum, F. culmorum, F. graminearum, F.
poae and F. sporotrichioides were isolated respectively from 50%, 10%, 20%, 40%
and 20% of examined grain dust samples. The presence of the mycotoxins produced
by Fusarium (moniliformin, deoxynivalenol, and nivalenol) was found altogether
in 70% of wheat grain samples (median = 0.1275 µg/g, range 0-1.480 µg/g) and in
90% of grain dust samples (median = 0.350 µg/g, range 0-1.090 µg/g).
Moniliformin (MON), deoxynivalenol (DON), and nivalenol (NIV) were each detected
in 40% of grain samples, and respectively in 80%, 40%, and 40% of grain dust
samples. Ochratoxin A (OTA) was detected in 60% of grain samples and in 60% of
grain dust samples (median in both cases was 0.0005 µg/g). The concentrations of
F. poae (p<0.05) and of total Fusarium species (p<0.01) in grain samples,
and the concentrations of F. culmorum and F. graminearum (p<0.05) in grain
dust samples were significantly correlated with the concentration of
deoxynivalenol. The concentrations of F. poae (p<0.05) and of total Fusarium
species (p<0.01) in grain dust samples were significantly correlated with the
concentration of total fusariotoxins. Moreover, the concentration of total
Fusarium species in grain dust samples was significantly correlated with the
concentration of nivalenol (p < 0.05). In conclusion, the majority of samples
of wheat grain and grain threshing dust collected on farms in eastern Poland
contained notable quantities of fusaria and/or fusariotoxins. This fact poses a
potential risk of mycotoxicoses to agricultural workers exposed to grain dust
when handling wheat during threshing, unloading, shuffling, and other farm
occupations.