Subjects with (n559) and without (n5167) asthma symptoms were randomly selected from the previous survey. Lung function and atopy were determined using spirometry and skin-prick tests,respectively. Inhalable dust levels were measured on the same day.
Subjects with (n559) and without (n5167) asthma symptoms were randomly selected from theprevious survey. Lung function and atopy were determined using spirometry and skin-prick tests,respectively. Inhalable dust levels were measured on the same day.