Table 4

Prevalence of respiratory symptoms and prevalence ratios (PR) of respiratory symptoms for above versus below median NAL concentrations of total cells and IL8 in waste collectors and controls

Prevalence ratio
Prevalence (%)Total cellsIL8
*p=0.05; **p=0.01; †p=0.10; ‡symptoms at any time during the past 12 months, or when shorter, during the time working at the facility; §calculated by adding one person in the diseased group.
Chronic symptoms:
    Cough >3 months in past 2 y20.012.80.790.451.261.98
    Cough with phlegm >3 months in past 2 y0.013.01.301.54>1.47§7.71*
    Shortness of breath when walking with contemporaries on the flat0.08.50.630.531.890.53
    Wheeze ever13.329.81.390.951.392.04†
    Wheeze >1 week in past 2 y6.714.90.631.581.892.64
    Asthma attacks ever6.712.81.580.261.582.11
Symptoms at any time during the past y:‡
    Cough with phlegm14.337.8†1.782.00†2.80†2.36*
    Wheeze in the chest14.221.61.391.331.514.28*
    Shortness of breath7.116.21.480.801.612.44
    Chest tightness7.
    Blocked nose42.962.*
    Runny nose50.†1.161.59*
    Itching nose or sneezing21.462.2**0.951.471.451.15
    Throat irritation14.329.71.342.33†1.032.14†