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[Field study of concentrations and emissions of particulate contaminants by types of swine houses in Korea].

OBJECTIVES
Particulate contaminants, such as total and respirable dusts, can harm the health of farm workers via several routes. The principal aims of this field study were to determine the concentrations and emissions of particulate contaminants: total and respirable dusts, in the different types of swine houses used in Korea, and allow objective comparison between Korea and the other countries in terms of swine housing types.


METHODS
The swine houses investigated in this research were selected with respect to three criteria: the manure removal system, ventilation mode and growth stage of pigs. Measurements of total and respirable dust concentrations and emissions in the swine houses were carried out on 5 housing types at 15 different farm sites per housing type. The swine houses investigated were randomly selected from farms situated within the central districts in Korea: province of Kyung-gi, Chung-buk and Chung-nam.


RESULTS
The total and respirable dust concentrations in the swine houses averaged 1.88 and 0.64 mg/m3, ranging from 0.53 to 4.37 mg/m3 and from 0.18 to 1.68 mg/m3, respectively. The highest concentrations of total and respirable dusts were found in the swine houses with deep-litter bed systems: 2.94 mg/m3 and 1.14 mg/m3, while the lowest concentrations were found in the naturally ventilated buildings with slats: 0.83 mg/m3 and 0.24 mg/m3, respectively (p<0,05). All the swine houses investigated did not exceed the threshold limit values (TLVs) for total (10 mg/m3) and respirable (2.5 mg/m3) dusts. The mean emissions of total and respirable dusts, per pig (75 kg in terms of live weight) and area (m2), from the swine houses were 97.33 and 9.55 mg/h/pig and 37.14 and 12.83 mg/h/ m2, respectively. The swine houses with deep-litter bed systems showed the highest emissions of total and respirable dusts (p<0.05). However, the emissions of total and respirable dusts from the other swine houses were not significantly different (p>0.05).


CONCLUSION
The concentrations and emissions of total and respirable dusts were relatively higher in the swine houses managed with deep-litter bed systems and ventilated naturally of the different swine housing types tested. In further research, more farms than the number used in this research should be investigated, which will present objective and accurate data on the concentrations and emissions of total and respirable dusts in Korean swine houses. In addition, personal sampling should be performed to objectively assess the exposure level of farm workers to particulate contaminants.