Photo credit: Hà Quốc Lập
by Daniel Fink, MD, Chair, The Quiet Coalition
Apologies in advance for a digression into medical terminology, but it’s important for understanding the implications of this blog post’s title, which comes from a paper from Susan Hansell’s research group in London. Hansell’s best known paper may be the one correlating road traffic noise with increased cardiovascular morbidity and mortality and increased all-cause mortality in London. The new report looked into long-term exposure to road traffic noise and the incidence of primary hypertension, or high blood pressure. It appeared in the American College of Cardiology’s publication JACC Advances.
I was taught in medical school (and in turn taught medical students and residents in internal medicine) that when a condition is called essential or age-related, it indicates that medical science doesn’t really understand the cause. That was true for essential hypertension decades ago and remains true today.
It’s not clear who first quipped, “England and America are two countries separated by the same language,” but that truism applies to medical terminology as well. In the United Kingdom, they don’t say essential hypertension. They instead say primary hypertension. In both countries that refers to the most common form of hypertension, which is very common and doesn’t have any known cause. There are secondary forms of hypertension with known causes, due to hormonal imbalances, arterial malformations or hormonal-secreting tumors, but those are relatively rare. I’ve only seen a few cases in a long medical career.
The research from Hansell’s group sheds some light on one possible cause of essential or primary hypertension: exposure to road traffic noise and associated air pollution. Using data collected by the UK Biobank, researchers identified all new cases of primary hypertension, and then correlated those cases with exposure to road traffic noise and air pollution — specifically fine particles (PM 2.5) and nitrogen dioxide. They found that increased exposure to both road traffic noise and air pollution associated with internal combustion engine exhaust increased the likelihood of developing high blood pressure.
The transition from vehicles powered by noisy, polluting internal combustion engines to cleaner, quieter electric vehicles is underway. In California, about 25% of new vehicles sold are EVs. In Norway, a stunning 89% of all new vehicles sold in March 2024 were EVs. Additionally, about 90% of all electric power in Norway comes from hydroelectric or wind sources, so there is zero air pollution associated with EV use there.
A quieter world with cleaner air will be a better and healthier world for all. And who knows, it may be one with fewer cases of essential or primary hypertension.
