They say that “health is wealth,” and anyone who’s struggling with their health, whether from the common cold or a chronic illness, will be quick to let you know how often we take our health for granted. We spend lots of time checking for ways to improve and protect our health, whether through supplements, new workouts, or the next overpriced health food craze.

It feels good to take proactive steps towards ensuring we’re healthy, but there are still many aspects of our health that are completely beyond our influence. One such health risk is air pollution.

While individual health risks like smoking and infectious diseases like tuberculosis have taken much of the focus for their fatal impacts, air pollution might surprise you in how dangerous it truly is for our health.

Researchers crunched the numbers to compare the subtraction from life expectancy that air pollution has as compared to other causes of death like smoking, HIV/AIDS, malaria, and violence. To their shock and probably to yours, air pollution is responsible causes an overall more significant loss in life expectancy than every single one of these conditions. Researchers concluded that air pollution is responsible for 8.8 million early deaths across the world in 2015 alone.

This study yielded lots of critical information, including which regions are most hard-hit my air pollution — East and South Asia are significantly more affected by air pollution and subsequent deaths than other regions. One unsurprising finding in this study? The countries with stricter air quality regulations saw the lowest mortality rates regarding air pollution.

However, don’t brush air pollution off as the problem of other regions. The researchers of this study also found that almost 800,000 Europeans suffer early deaths yearly caused by illnesses related to air pollution. The quality of air in our cities affects us all. In Europe, researchers concluded that polluted air shortens the lifespan of Europeans by over two years.

Air pollution is particularly dangerous because of how hard it is to protect yourself against it. Sure, you can wear a super strength particle filtration mask everywhere, and that will help, but who really wants to wear a face mask constantly? The best way to defend against air pollution is to make sure it doesn’t exist, to begin with. The researchers in this study found that most air pollution results from fossil fuel usage. Sometimes taking care of our health means making sure our environment stays healthy too.