Loud road traffic a cardiovascular hazard

A recent study has sounded the alarm on road-traffic noise, suggesting that higher levels of exposure may increase the risk of stroke.

The study involved the entire Danish population. Researchers estimated road-traffic and railway noise (Lden) at the most and least exposed façades for all residential addresses across Denmark (about 2.8 million) within the period of 1990–2017. This served as the basis for the 10-year time-weighted mean noise exposure for 3.6 million Danes aged >35 years.

Associations were analysed using Cox proportional hazards models. These models were controlled for various individual- and area-level demographic and socioeconomic covariates sourced from registries, as well as for air pollution (fine particulate matter with particles having a diameter of ≤2.5 µm [PM2.5] and nitrogen dioxide [NO2]).

A total of 184,523 individuals developed incident stroke over the follow-up (2000–2017). The risk of incident stroke showed a positive relationship with road-traffic noise exposure.

Specifically, the incidence rate ratio (IRR) of all strokes associated with every 10-dB increase in the 10-year mean road-traffic noise at the most exposed façade was 1.04 (95 percent confidence interval [CI], 1.03–1.05). For road-traffic noise at the least exposed façade, the IRR per 10 dB was 1.03 (95 percent CI, 1.02–1.04).

Meanwhile, railway noise had a null effect on the risk of stroke.

These present data point to the potential of road-traffic noise as a cardiovascular risk factor.