Table 2

 Comparisons of leavers and active workers according to their work related symptoms and lung function tests at each follow up period point

2nd survey (first month)3rd survey (third month)4th survey (sixth month)5th survey (first year)
LeaversActive workersLeaversActive workersLeaversActive workersLeaversActive workers
WR-LRTS, work related lower respiratory tract symptoms; WR-URTS, work related upper respiratory tract symptoms; Δ, change.
*p<0.005.
WR-LRTS, n/N0/165/1576/246/1253/1717/1110/174/93
(%)(3.2)(25.0)*(4.8)(17.6)(15.3)(4.3)
WR-URTS, n/N4/1650/15712/2449/1257/1749/1114/1732/93
(%)(25.0)(31.8)(50.0)(39.2)(41.2)(44.1)(23.5)(34.4)
Cross shift ΔFEV13/1631/1462/2316/1230/1710/1113/1721/92
−5% ⩽, n/N (%)(18.8)(21.2)(8.7)(13.0)(9.0)(17.6)(22.8)
Cross week ΔFEV14/1347/1383/1926/1101/1718/1114/1721/91
−5% ⩽, n/N (%)(30.8)(34.1)(15.8)(23.6)(5.9)(16.2)(23.5)(23.1)