Experimental Study on the Effect of Urban Road Traffic Noise on Heart Rate Variability of Noise-Sensitive People

Epidemiological studies have confirmed that long-term exposure to road traffic noise can cause cardiovascular diseases (CDs), and when noise exposure reaches a certain level, the risk of related CDs significantly increases. Currently, a large number of Chinese residents are exposed to high noise exposure, which could greatly increase the risk of cardiovascular disease. On the other hand, relevant studies have found that people with high noise sensitivity are more susceptible to noise. And it is necessary to pay more attention to the high noise-sensitive people. This study investigated the acute physiological effect of different noise-sensitive groups by indoor-level noise stimulus experiments under laboratory conditions, by observing heart rate variability (HRV) indicators, including standard deviation of NN intervals (SDNN), low frequency/high frequency (LF/HF), and heart rate (HR). The results showed that (a) there was no significant difference in HRV between the high-sensitive group and the low-sensitive group at the physiological baseline and the different stimulating noise levels. (b) Then, based on the theory of cumulative effect of noise proposed by WHO Regional Office for Europe, non-significant but observable differences between groups were further discussed. By analyzing differences of the variation trends and the within-group significant changes of SDNN and HR between the two groups, the results tended to show that the high-sensitive group is more affected by road traffic noise. In addition, the values of SDNN and HR showed observable between-group differences at 55 dB (A) and 65 dB (A) which corresponding to the SPL associated with a significantly increased risk of cardiovascular disease concerned by epidemiological studies. According to the cumulative effect theory (WHO), these differences in HRV caused by short-term noise stimulation may have the potential to produce physiological response and lead to between-groups differences in prevalence after long-term recurrent effect, and deserve attention and further research.

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Long-term air pollution and road traffic noise exposure and COPD: the Danish Nurse Cohort

European Respiratory Journal ◽

10.1183/13993003.04594-2020 ◽

2021 ◽

pp. 2004594

Author(s):

Shuo Liu ◽

Youn-Hee Lim ◽

Marie Pedersen ◽

Jeanette T. Jørgensen ◽

Heresh Amini ◽

...

Keyword(s):

Air Pollution ◽

Noise Exposure ◽

Cox Regression ◽

Road Traffic ◽

Traffic Noise ◽

Potential Interaction ◽

Chronic Obstructive ◽

Road Traffic Noise ◽

Obstructive Pulmonary Disease

BackgroundWhile air pollution has been linked to the development of chronic obstructive pulmonary disease (COPD), evidence on the role of environmental noise is just emerging. We examined the associations of long-term exposure to air pollution and road traffic noise with COPD incidence.MethodsWe defined COPD incidence for 24 538 female nurses from the Danish Nurse Cohort (age>44 years) as the first hospital contact between baseline (1993 or 1999) and 2015. We estimated residential annual mean concentrations of particulate matter with diameter<2.5 µm (PM2.5) since 1990 and nitrogen dioxide (NO2) since 1970 by the Danish DEHM/UBM/AirGIS modeling system, and road traffic noise (Lden) since 1970 by the Nord2000 model. Time-varying Cox regression models were applied to assess the associations of air pollution and road traffic noise with COPD incidence.Results977 nurses developed COPD during 18.6 years’ mean follow-up. We observed associations with COPD for all three exposures with hazard ratios (HRs) and 95% confidence intervals (CIs) of 1.19 (1.01, 1.41) per 6.26 µg·m−3 for PM2.5, 1.13 (1.05, 1.20) per 8.19 µg·m−3 for NO2, and 1.15 (1.06, 1.25) per 10 dB for Lden. Associations with NO2 and Lden attenuated slightly after mutual adjustment, but were robust to adjustment for PM2.5. Associations with PM2.5 were attenuated to null after adjustment for either NO2 or Lden. No potential interaction effect was observed between air pollutants and noise.ConclusionsLong-term exposure to air pollution, especially traffic-related NO2, and road traffic noise were independently associated with COPD.

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