Table 3

Adjusted HRRs and 95% CIs for cardiovascular disease among 3499 welders according to accumulated exposure to particles

Cardiovascular diseaseCumulative particulate exposure (mg/m3×years)N*No. of casesHRR95% CI
Acute myocardial infarct0–10 (reference)37991171
10–50163075671.110.65 to 1.89
50–100184292961.430.85 to 2.41
>100150199801.030.61 to 1.74
  • Log-rank test, χ2=5.95, p=0.114

  • Test for trend, χ2=0.00, p=0.969

Angina pectoris0–10 (reference)44954171
10–50194825801.230.73 to 2.08
50–1002261621071.410.84 to 2.36
>100181557951.210.72 to 2.03
  • Log-rank test, χ2=2.26, p=0.521

  • Test for trend, χ2=0.22, p=0.637

Chronic ischaemic heart disease0–10 (reference)3161371
10–50131588612.511.15 to 5.49
50–100162675832.791.29 to 6.04
>100143045601.700.78 to 3.72
  • Log–rank test, χ2=13.56, p=0.004

  • Test for trend, χ2=0.27, p=0.606

Cerebral infarct0–10 (reference)1547771
10–5063815321.320.58 to 3.01
50–10076279321.170.52 to 2.67
>10066747521.540.70 to 3.39
  • Log-rank test, χ2=2.44, p=0.486

  • Test for trend, χ2=1.12, p=0.290

  • Results for welders who answered all the questions necessary for calculation of their cumulative exposure across all years and who answered questions about smoking, alcohol consumption and use of medicines.

  • * Numbers correspond to data split on every incidence of each disease for all welders, in order to include the time-dependent variable, duration of welding after baseline. As each man contributed a different number of years for each incidence, each was included more than once in the analysis.

  • Adjusted for calendar year, tobacco smoking, alcohol consumption and use of hypertension or ‘heart’ medicine.