HEART DISEASE ATTRIBUTED TO OCCUPATIONAL NOISE, VIBRATION AND OTHER CO-EXPOSURE: SELF-REPORTED POPULATION-BASED SURVEY AMONG BULGARIAN WORKERS

Background: Cardiovascular disease (CVD) is the main mortality cause worldwide. Noise and vibration are considered to be occupational risk factors, but little is known about their cardiovascular effects in Bulgaria in terms of gender and various professional groups. The aim of this study has been to investigate the risk of prevalent CVD, associated with occupational noise and vibration exposure. Material and Methods: We conducted a secondary analysis of the data from 3 waves of the European Working Conditions Survey (EWCS) 2001-2010 - a nationally-representative cross-sectional questionnaire survey covering 3149 workers aged >= 15 years in Bulgaria. Data on self-reported heart disease were linked to self-reported occupational noise and vibration, adjusting for other factors. Results from the 3 waves were pooled together using the inverse variance heterogeneity (IVhet) meta-analysis. Results: For noise, the risk was elevated among women (relative risk (RR) = 1.26, 95% confidence interval (CI): 0.53-3.01), but not men (RR = 0.49, 95% CI: 0.14-1.65). Long-term workers had RR = 1.01, 95% CI: 0.60-1.69. For vibration, the risk was increased in all participants. It was higher among men (RR = 2.56, 95% CI: 1.60-4.09) than it was among women (RR = 1.32, 95% CI: 0.77-2.27). Among long-term, industrial, and service workers it was RR = 1.56, 95% CI: 1.02-2.40; RR = 1.10, 95% CI: 0.61-1.98, and RR = 1.18, 95% CI: 0.57-2.46, respectively. Conclusions: Occupational vibration was a risk factor for prevalent heart disease in Bulgaria. Noise was an alleged risk factor only among long-term workers and women.