Aircraft noise linked to heightened risk for CVD

Exposure to aircraft noise was associated with increased risk for CVD and CV-related hospitalization, as reported in two new studies published in the British Medical Journal.

In an accompanying editorial, Stephen Stansfeld, MBBS, PhD, MRCP, FRCPsych, of Queen Mary University of London, said these studies “provide preliminary evidence that aircraft noise exposure is not just a cause of annoyance, sleep disturbance and reduced quality of life, but may also increase morbidity and mortality from cardiovascular disease.”

Risk for older people living near airports

For the first study, researchers investigated whether exposure to aircraft noise increased risk for hospitalization. The retrospective study included 6,027,363 adults older than 65 years living in 2,218 ZIP codes around 89 US airports. The researchers matched contours of aircraft noise levels around those airports from 2009 Federal Aviation Administration data to census block resolution population data.

The primary outcome was percentage increase in hospital admission rate for CVD associated with a 10-decibel (dB) increase in aircraft noise, adjusted for age, sex, race, ZIP code-level socioeconomic status/demographics, ZIP code-level air pollution and roadway density. After controlling for covariates, an increase in the 90th percentile noise of 10 dB was associated with a 3.5% increase in CV-related hospital admissions. Variation between airports was not a factor, the researchers found.

Analysis also yielded positive but nonsignificant associations between hospitalizations for individual CVDs and aircraft noise.

“Further research should refine the associations and strengthen causal interpretation by investigating modifying factors at the airport or individual level,” the researchers wrote.

Risk for people living near Heathrow Airport

The second study focused on 3.6 million residents living near Heathrow Airport in London. According to the findings, high levels of aircraft noise were associated with elevated risk for stroke, CHD and CVD for both hospital admissions and mortality.

For the study, the researchers compared rates of CVD hospitalizations and mortality in neighborhoods exposed to different levels of aircraft noise, using A-weighted equivalent sound pressure level as a noise metric.

Compared with the lowest levels of daytime aircraft noise (≤51 dB), participants who experienced the highest levels of daytime aircraft noise (>63 dB) had a greater RR for several outcomes, including hospitalizations for stroke (RR=1.24; 95% CI, 1.08-1.43), CHD (RR=1.21; 95% CI, 1.12-1.31) and CVD (RR=1.14; 95% CI, 1.08-1.2). RRs for mortality related to those conditions were similar but had wider confidence limits. The figures were adjusted for age, sex, ethnicity, deprivation and lung cancer mortality. Additionally, South Asian ethnicity was identified as a potential confounder in the study

“Policy decisions need to take account of potential health-related concerns, including possible effects of environmental noise on CV health,” the researchers wrote.

For more information:

Correia AW. BMJ. 2013;doi:10.1136/bmj.f5561.

Hansell AL. BMJ. 2013;doi:10.1136/bmj.f5432.

Disclosure: The researchers report no relevant financial disclosures.