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A survey of size-fractionated dust exposure was carried out in 10 wood processing plants across the United States as part of a 5-year longitudinal respiratory health study. The facilities included a sawmill, plywood assembly plants, secondary wood milling operations, and factories producing finished wood products such as wood furniture and cabinets. Size-fractionated dust exposures were determined using the RespiCon Personal Particle Sampler. There were 2430 valid sets of respirable, thoracic, and inhalable dust samples collected. Overall, geometric mean (geometric standard deviation) exposure levels were found to be 1.44 (2.67), 0.35 (2.65), and 0.18 (2.54) mg/m, for the inhalable, thoracic, and respirable fractions, respectively. Averaged across all samples, the respirable fraction accounted for 16.7% of the inhalable dust mass, whereas the corresponding figure for thoracic fraction as a percentage of the inhalable fraction was 28.7%. Exposures in the furniture manufacturing plants were significantly higher than those in sawmill and plywood assembly plants, wood milling plants, and cabinet manufacturing plants, whereas the sawmill and plywood assembly plants exhibited significantly lower dust levels than the other industry segments. Among work activities, cleaning with compressed air and sanding processes produced the highest size-fractionated dust exposures, whereas forklift drivers demonstrated the lowest respirable and inhalable dust fractions and shipping processes produced the lowest thoracic dust fraction. Other common work activities such as sawing, milling, and clamping exhibited intermediate exposure levels, but there were significant differences in relative ranking of these across the various industry segments. Processing of hardwood and mixed woods generally were associated with higher exposures than were softwood and plywood, although these results were confounded with industry segment also. [ABSTRACT FROM AUTHOR]

Winter barley (Hordeum vulgare L.), a potential feedstock for fuel ethanol production, may be contaminated with the trichothecene mycotoxin deoxynivalenol (DON). DON is a threat to feed and food safety in the United States and may become concentrated during the production of distillers dried grains with solubles (DDGS). DDGS is a coproduct of fuel ethanol production and is increasingly being used as feed for domestic animals. Therefore, new strategies to reduce the threat of DON in DDGS need to be developed and implemented for grain destined for fuel ethanol production. It is known that large concentrations of DON accumulate in the hulls of wheat and barley. Consequently, improved methods are needed to carefully remove the hull from the grain and preserve the starchy endosperm. Whole kernels from five Virginia winter barley genotypes were used to evaluate the abilities of two different milling strategies (roller milling and precision milling (FitzMill)) for their ability to remove the hull-enriched tissue from the kernel while maintaining starch levels and reducing DON levels in the endosperm-enriched tissue. After whole kernels were milled, DON and starch levels were quantified in the hull-enriched fractions and endosperm-enriched fractions. Initial milling experiments demonstrated that the precision mill system (6 min run time) is able to reduce more DON than the roller mill but with higher starch losses. The average percent DON removed from the kernel with the roller mill was 36.7% ± 5.5 and the average percent DON removed from the dehulled kernel with the precision mill was 85.1% ± 9.0. Endosperm-enriched fractions collected from the roller mill and precision mill contained starch levels ranging from 49.0% ± 12.1 to 59.1% ± 0.5 and 58.5% ± 1.6 to 65.3% ± 3.9, respectively. On average, the precision mill removed a mass of 23.1% ± 6.8 and resulted in starch losses of 9.6% ± 6.3, but produced an endosperm-enriched fraction with relatively very little average DON (5.5 ± 2.7 μg g(-1)). In contrast, on average, the roller mill removed a mass of 12.2% ± 1.6 and resulted in starch losses of 2.1% ± 0.5, but produced an endosperm-enriched fraction with high average DON (20.7 ± 13.5 μg g(-1)). In a time course precision milling experiment, we tested barley genotypes Nomini, Atlantic, and VA96-44-304 and attempted to reduce the starch loss seen in the first experiment while maintaining low DON concentrations. Decreasing the run time of the precision mill from 5 to 2 min, reduced starch loss at the expense of higher DON concentrations. Aspirated fractions revealed that the precision milled hull-enriched fraction contained endosperm-enriched components that were highly contaminated with DON. This work has important implications for the reduction of mycotoxins such as DON in barley fuel ethanol coproducts and barley enriched animal feeds and human foods.