Could industrial noise be regarded as a risk factor for arterial hypertension?

The aim of this study was to determine whether occupational noise exposure is a risk factor that may favour a chronic increase of diastolic and systolic blood pressure and a higher prevalence of arterial hypertension. A cross-sectional study was performed on 1372 workers employed in 11 cement plants in central and southern Italy. In 1985 the workers were subjected to a medical examination during which blood pressure was measured and information about personal features, occupational activity, diseases, family history of hypertension, use of antihypertensive drugs, smoking habit and alcohol intake were also gathered by questionnaire. For each worker noise exposure (dBA) was estimated using a series of indicators representing both the levels of exposure at the time of study and loud energy previously absorbed during the occupational life spent in the industry considered. 41.4% of the examined workers were hypertensive, according to the World Health Organization (WHO) definition (i.e. systolic blood pressure (SBP) levels ≥140 and/or diastolic blood pressure (DBP) levels ≥90 mmHg and/or reported antihypertensive treatment). Linear regression analysis showed a positive influence of age, BMI and use of antihypertensive drugs for both systolic and diastolic blood pressure. Noise exposure, independent of the indicators, was negatively associated with diastolic blood pressure only. The logistic regression analysis of the different variables contributing to high blood pressure showed a positive influence of age, BMI and family history of hypertension, while only some indicators of noise exposure were found to be negatively associated with arterial hypertension. Noise exposure, as assessed by all the different indicators used in the study, does not seem to influence systolic arterial pressure, but does have a negative influence on diastolic pressure. The prevalence of arterial hypertension, as defined by WHO criteria, appears negatively associated with noise exposure. The results obtained could be related both to a physiological variation of blood pressure following chronic noise exposure and to an unfavourable combination of elements further accentuated by the limitations of the cross-sectional study. Copyright © 1999 John Wiley & Sons, Ltd.