Cardiovascular disease mortality among retired workers chronically exposed to intense occupational noise
Objective The aim of this study, conducted among retired workers (≥65 years), is to estimate the association between long-term risk of cardiovascular disease (CVD) death and (1) duration of occupational noise exposure in career and (2) noise-induced hearing loss (NIHL), the latter being used as an indicator of adverse effects for long-term exposure to occupational noise.
Methods Data from screening activities of occupational NIHL were paired to data from death records and were used for this study. A nested case–control analysis was performed. Each case was matched with three controls for length of follow-up and economic sector. A total of 161 CVD deaths occured during an average follow-up of 6.8 years. Conditional logistic regression models were used to estimate the risk (OR) of CVD death by tertiles of duration of noise exposure and of NIHL.
Results Conditional logistic regression models indicated that prolonged duration of noise exposure (≥36.5 years) (3rd tertile) was associated with an increased risk of CVD death (OR 1.70; 95 % CI 1.10–2.62), as compared with shorter duration (<27 years) (first tertile). Moderate NIHL (2nd tertile) (OR 1.64; 95 % CI 1.04–2.6) and severe NIHL (3rd tertile) (OR 1.66; 95 % CI 1.06–2.60) were also associated with an increase in risk of CVD death.
Conclusions Results are consistent with recent findings on the chronic effects of occupational noise exposure persisting after retirement although it is less than during active working life.