Urban residential road traffic noise and hypertension: a cross-sectional study of adult population.

Results from studies involving exposure to road traffic noise and risk of hypertension are diverse and have seldom reached statistical significance. This study was designed with the aim of investigating whether there is any association between road traffic noise and prevalence of hypertension in an urban adult population. Similar studies have never been reported from India. A cross-sectional study was performed on 909 adults (533 female and 376 male) aged 18-80 years residing in close proximity to roadways in Asansol City. Time-weighted equivalent noise level (L den) was estimated using a standard modeling platform. Odds for hypertension in relation to traffic noise exposure were estimated by univariate and multifactorial logistic regression. The adjusted odds ratio (OR) for self-reported hypertension was 1.99 (95 % confidence interval (CI) 1.66-2.39) per 5 dB(A) increase of L den (range 55.1-77.9). A gender-related risk difference was observed among the male (OR 1.81 (1.42-2.31)) and female (OR 2.18 (1.66-2.88)) respondents. For increase in 9 years of age, the odds of hypertension risk increased by 60 % (OR 1.66 (1.43-1.91) among those exposed above L den 60 dB(A). Vulnerable subgroups were female aged 35-54 years and male aged 45-54 years. The study suggests that a threshold exposure to road traffic noise at L den > 65 dB(A) for men and L den > 60 dB(A) in women may be associated with the occurrence of hypertension.