Traffic noise is one of the more debilitating sounds a human being can experience, long term. This is because continual exposure can impact blood pressure, heart health, mental health, and more. That’s before any of the other negative impacts associated with pollution. We have covered the links between noise and health impacts in previous blogs. But today, I’m going to share a recent paper that reviews data on the stress response to noise.
Inflammation and oxidative stress
The paper is titled “Road traffic noise exposure and its impact on health: evidence from animal and human studies—chronic stress, inflammation, and oxidative stress as key components of the complex downstream pathway underlying noise-induced non-auditory health effects”, which kind of tells you the punchline. Yes, chronic inflammation and oxidative stress appear to be the main result of noise-induced stress. Unfortunately, there is still not enough data to tell us why, or how.
According to the authors, these two factors are responsible for vascular dysfunction, disruption of the circadian rhythm, accelerated aging, neuroinflammation, and changes in microbiome. That last one was news to me — that gut health could be impacted by road traffic noise?!
Traffic noise and gut health
Turns out it’s a bit of a stretch to link the microbiome to road noise, at present. The authors are mostly drawing on research linking stress to gut health. There are also a few animal studies that link noise to microbiome, on rats and mice.
Good to know if you have rodents as pets. For example, if you expose your mouse to noise for four hours a day for a month, he or she will end up with decreased gut microbiota diversity. But never fear, some enterprising researchers managed to cure their rats of the noise-induced microbiota imbalance by feeding them probiotics. Apparently that helped them a lot!
However, research has not yet been done on humans. Though there may well be some in the future, so stay tuned!
Conclusions
Essentially, exposure to a lot of noise from traffic is unavoidable for 55% of the global population living in cities. This number projected to rise to 68% by 2050. Which explains why so much research is being done to try and figure out what the human health impacts are.
The authors confirm it’s bad for humans to be exposed to noise. However, researchers are still mostly in the dark as to exactly why. Thankfully, as detailed in our previous blogs, there are also plenty of solutions, and more in the works.