Noise has non-auditory health effects, too

by admin

In the second of a series of medical guest posts, SoundPrint’s Medical Advisor Daniel Fink MD explains why excessive noise and loud restaurants are bad for patrons and venue employees.


Daniel Fink MD, Medical Advisor to SoundPrint 

It is generally known that noise exposure causes hearing loss, even if the safe noise level to avoid hearing loss is widely misinterpreted, but it is less well known that noise has non-auditory health effects, too.  These adverse health effects are remnants of evolution eons ago that remain with us today.

The hearing sense developed from a primitive vibration sense, used even in single-celled animals either to find food or to avoid becoming another animal’s food.  In the wild, that is still the primary use of hearing for many species, although communication with other members of the species and even members of other species also developed.

Sound is measured in decibels.  As shown by the National Park Service noise map  [1], the natural condition is quiet.  There are only a few natural sources of loud noise: thunderstorms, waterfalls, landslides, and sometimes animals calls.  The night is especially quiet.

National Park Service Sound Map- Natural Conditions (Green = Sound Pressure Level (SPL) 40 dBA, Brown = SPL 30 dBA)

Most reptiles, amphibians, and mammals close their eyes, but only a few marine species can close their ears.  In general, noise is a warning sign of approaching danger, be it the roar of a lion across the veldt, the snap of a twig in the forest, or the rush of a hawk’s wings.  Because of this, noise causes three involuntary stress responses, to prepare the animal to deal with the perceived danger. The first is an autonomic nervous system response, including increased pulse and blood pressure.  The second is an increase in stress hormone levels. The third is an inflammatory response.

These responses have been studied in animal models in the laboratory, and in human experiments and epidemiology studies.  The best English-language reviews are by Hammer et al. [2] and Basner et al. [3].  These authors discuss the myriad adverse health effects of noise, including hypertension, diabetes, heart attack, stroke, and death.  The effects are small on each exposed person, but because hundreds of millions of people are exposed, the population health effects are large.  As reviewed by Munzel et al. {4, 5], the best studies of noise on health are those of transportation noise on cardiovascular health.  The research is definitive. As Babisch noted  the question isn’t whether there is an effect of noise on cardiovascular health, but on the precise nature of the exposure-response relationship. [6] This graph from Basner et al. [3] shows the current understanding of the relationship between transportation noise exposure and cardiac disease.

 

Figure 3 Relative risks of noise exposure and adverse cardiovascular outcomes

RTN: Road Traffic Noise   AN: Aircraft noise   From Basner et al, Auditory and non-auditory effects of noise on health, Lancet 2014; 383:1325-2332 [3]

Furthermore, Basner stated that most researchers in the field think the data are strong enough to establish causality, not merely a correlation. [7] The data are less complete for other adverse health effects of noise, including effects on obesity [8], infertility, [9] and cognitive health [10] but there is little reason to doubt that research will eventually show the same adverse health effects of noise.

Most people don’t spend enough time in noisy restaurants to suffer adverse health effects just from this noise exposure, but the cumulative effect of noise exposure can’t be good for health.  For those who frequently go to restaurants, e.g. for lunch during the work week and several times a week for dinner, and especially for those who work in restaurants, the average noise levels may be high enough to cause both hearing loss (see article here) and non-auditory adverse health effects as well.

 

REFERENCES

  1. National Park Service, Mapping Sounds (Natural Sounds). Available at  https://www.nps.gov/subjects/sound/soundmap.htm
  1. Hammer MS, Swinburn TK, Neitzel RL, Environmental noise pollution in the United States: a public health perspective. Environ Health Perspect 2014;122:115-119 Available at http://dx.doi.org.10.1289/ehp.1307272
  2. Basner M, Babisch W, Davis A, et al. Auditory and non-auditory effects of noise on health. Lancet 2014;383:1325-1332 Available at http://dx.doi.org/10.1016/S0140-6736(13)61613-X
  3. Munzel T, Gori T, Babisch W, Basner M, Cardiovascular effects of environmental noise exposure, Eur Heart J 2014;35:829-836 Available at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3971384/
  4. Munzel T, Schmidt FP, Steven S, et al. Environmental noise and the cardiovascular system. JACC 2018;71:688-697 Available at http://www.onlinejacc.org/content/71/6/688
  5. Babisch W, Cardiovascular effects of noise. Noise Health 2011;13:201-204 Available at http://www.noiseandhealth.org/text.asp?2011/13/52/201/80148
  6. Basner M, Much ado about noise. DtschArztebl 2016;113:405-406 Available at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4939426/#
  7. Pyko A, Eriksson C, Oftedal B et al. Exposure to traffic noise and markers of obesity. Occ Environ Med 2015;72:594-601 Available at https://oem.bmj.com/content/early/2015/04/28/oemed-2014-102516
  8. Ristovska G, Laszlo HE, Hansell AL. Reproductive outcomes associated with noise exposure- A systematic review of the literature. Int J Env Res Public Health 2014;11:7931-7952 Available at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4143841/#
  9. Tzivian L, Winkler A, Dlugal M, et al. Effects of long term outdoor air pollution and noise on cognitive function in adults. Int J Hyg Environ Health2015;218(1):1- 11 Available at https://doi.org/10.1016/j.ijheh.2014.08.002