Morbidity from ischemic heart disease in workers at a stainless steel welding factory

Abstract

ABSTRACT

Objectives:

Methods:

Results:

Conclusion:

Key terms:

Angina pectoris, cardiovascular diseases, grinding, ischemic heart disease, metal workers,

myocardial infarction, stainless steel, welding

In accord with some other studies, the results of the study support a hypothesis that there may

be a relation between exposure factors to which stainless steel metal workers are exposed and an increased

risk of ischemic heart disease.

There were 236 men from the study group and 989 men from the control group who fulfilled the

inclusion criteria, and who answered the questionnaires. The bivariate analysis showed that the study group

had an increased age and smoking adjusted prevalence of "chest pain on exercise" and "angina pectoris"

with ratios 2.3 (95% CI 1.5–4.9) and 2.6 (95% 1.2–5.7) respectively. When using multiple logistic regression

analysis with control for potential confounding factors, the odds ratios for the study group as compared

to the control group, were 2.6 (95% CI 1.3–5.3) for "chest pain on exercise", 2.5 (95% CI 1.1–5.8) for

"angina pectoris", and 2.4 (95% CI 1.1–4.9) for myocardial infarction. The only explanatory variable which

showed statistically significant increased odds ratios for all three outcome variables was work with grinding,

with 2.4 (95% CI 1.0–5.5), 3.3 (1.3–8.5), and 2.5 (1.1–5.9) respectively.

All the men who had worked at the plant for more than one year since 1960, and who were under

the age of 70 years at the time of the study, were included in the study group. The control group was

randomly selected from the male population of the same town, and was categorically matched for age. A self

administered questionnaire was used to collect information on the occurrence of CVD and related symptoms,

background variables, and exposure factors. The validity of the outcome variables for a subgroup of

the participants was checked with their appointed general practitioners. This validation revealed a low sensitivity

and a high specificity for the outcome variables “chest pain on exercise” and “angina pectoris”, while

for “myocardial infarction” both the sensitivity and the specificity of the answers given were high.

To investigate whether there was an increased morbidity from cardiovascular diseases (CVD)

among welders and other workers at a stainless steel welding factory, and, if so, to see whether morbidity

could be linked to specific exposure factors.