The common activity that’s slowly killing you

By Naveed Saleh, MD, MS
Published June 25, 2020

Key Takeaways

With restaurants, sporting events, malls, and other “non-essential” services shut down across the country during the COVID-19 pandemic (nightmare?) and stay home orders, there were a lot less people driving around. (Even as the country begins to open up, there are still lower traffic volumes.) In fact, according to research by the US Public Interest Research Group, a federation of US and Canadian nonprofits founded by political activist Ralph Nader, household vehicle travel dropped by between 68% and 72% from mid-March to the first week of April 2020. But, this drop in car travel isn’t necessarily a bad thing. 

After all, cars can be harmful to your health for several reasons. While some of these health hazards may be more obvious, there are some you may not have considered. Let’s take a closer look at some of the health risks of driving. 

Critical injury

Each year, about 3 million Americans experience nonfatal injuries due to motor vehicle accidents, with more than 100 dying per day, according to the CDC. In 2016, more than 290,000 Americans were treated in emergency rooms for motor vehicle crash injuries. What makes things worse is that decreased mobility that often accompanies older age can increase the severity of motor vehicle injuries.

To date, the focus on motor vehicle injury has largely been on child passenger safety, without evidence that this initiative works to curb crash injury risk. But, if legislators focused on the general population—including more vulnerable groups at risk for crash injury like the elderly— perhaps initiatives for risk reduction could be more impactful. For instance, some evidence-based interventions that have been shown to decrease the frequency of motor vehicle crash injuries include automated red-light enforcement with cameras, automated speed-camera enforcements, alcohol ignition interlocks, sobriety checkpoints, stricter enforcement of seatbelt laws, and mandatory bike helmet and motorcycle helmet laws. But, what can you do to drive down critical injury on a personal level? 

According to the authors of a review article published in the Journal of Public Health, if more people cycled or walked rather than drove, lower traffic volumes could result in reduced injury. In addition, life years gained from regular cycling outweighs years lost from crashes by ~10-fold. 

So, what are you waiting for? Break that bike out of the garage! (Just make sure that you are wearing a helmet and following social-distancing measures, of course.)


No matter how much head bopping occurs to the music of the car radio, driving around is no form of exercise. Instead, substituting car travel with walking or cycling would slow the rates of obesity. In countries that have higher levels of active transport—such as the Netherlands, Denmark, and Sweden—obesity rates are lower, with every additional kilometer walked per day linked to a 4.8% drop in the risk of obesity. On the other hand, every additional hour spent in the car is linked to a 6% boost in obesity rates. 

Aside from lower obesity levels, in terms of physical activity, choosing active forms of transportation contributes to decreased incidence of heart disease, diabetes, osteoporosis, depression, and some cancers. Moreover, physically active adults have a 20% to 30% decreased risk of premature death.


Research has tied noise pollution from intersections to hypertension (even in children), sleep disturbance (which can have major health repercussions), and minor psychiatric illness. For instance, in a small survey evaluating the psychosocial effects of traffic noise exposure, the investigator found that “a higher proportion of those who lived in the noisy area in apartments with windows facing the street more often felt depressed,” while “those who had windows facing the courtyard, in the noisy area, however, were not more depressed [than] those who lived in the quiet area.”

Furthermore, in a review article published in the British Medical Bulletin, researchers examined the non-auditory effects of noise on health. They found both subjective accounts and objective research showing that noise exposure disturbs sleep in a proportional manner, thus resulting in an increase in the rate of changes in sleep stages, as well as number of awakenings. 


Worldwide, air pollution results in more than 1 million deaths per year by means of heart disease and cancers. Pollution caused by motor vehicles results in an estimated 30% of emissions of a type of small particulate matter called PM2.5 and 50% of PM0.1. Small particulate matter is the most dangerous component in pollution, and can infiltrate mucous membranes of the lungs and skin to cause damage to the heart, lungs, and brain. 

Children are at highest risk of air pollution-related health problems, with exposure linked to respiratory disease, cognitive impairment, and childhood cancers.

Here are some tips from the WHO on how to decrease exposure to air pollution in areas congested with motor vehicle traffic:

  • Limit walking on streets during rush hour, and caregivers should lift children above the level of street exhaust.

  • Limit time spent at traffic hotspots where cars are running idle and spewing exhaust.

  • When exercising outdoors, do so in less polluted areas like parks.

Climate change

Emissions from cars contribute substantially to climate change, and the potential effects of climate change on health are downright scary. These projected effects are engagingly outlined in an interactive article published in the New England Journal of Medicine.

“Climate change is a major public health emergency,” wrote the authors. “Its consequences directly affect the practice of medicine in every specialty and are projected to threaten the stability of our health care systems. Understanding the effects of climate change on human health and health care delivery, especially for the most vulnerable populations, is critical for health care professionals. Moreover, interventions are needed that protect human health and ensure the resiliency of health care systems.”

The researchers highlighted the following key points:

  • With respect to the cardiovascular system, particulate air pollutants negatively contribute to atherosclerosis, poor endothelial function, thrombosis, and poor vascular tone. Extreme drought, heat, and wildfire smoke secondary to climate change have also been linked to cardiovascular complications.

  • Infectious gastrointestinal illnesses resulting from vector- and water-borne pathogens are highly sensitive to changes in climate, which could lead to Salmonella and Campylobacter outbreaks

  • Extreme warming and ozone depletion increase the risk of skin cancer. Furthermore, ocean warming, rising sea levels, and flooding may lead to increased waterborne diseases with dermatological presentations. Specifically, Vibro can cause cellulitis or a necrotizing infection with open wounds. Moreover,opportunistic algae infections can lead to inflammatory granulomatous lesions in the skin.

  • Air pollution, severe heat, food/water scarcity, and more could impact maternal health, leading to adverse pregnancy outcomes—including low birth weight, spontaneous abortion, preterm birth, and increased neonatal mortality.

How to protect yourself 

Some of the effects of cars on health are more intangible in nature. For instance, people who live in neighborhoods more amenable to walking have increased social interactions, as well as higher levels of trust and participation, compared with those living on busy intersections. Research shows that such social participation is linked to a four-fold decrease in all-cause mortality.

In the end, it’s clear that if a choice is available, it’s always best to opt for more active forms of transportation like cycling and walking. In areas where walking or cycling aren’t feasible, mass transit is still a better option than a car, given the reduced emissions per passenger compared with one person or a small group in a car. In fact, taking public transport can result in $355 in health benefits per year, according to the CDC. No matter which option you choose, just remember to wear a mask and keep a safe distance from others.

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