Asthma rates have increased significantly in recent decades, with the number of people diagnosed with asthma in the United States growing 4.3 million between 2001 and 2009. In some cases, the rise could be a result of overdiagnosis; it could also be partially explained by what experts call the “hygiene hypothesis,” which says today's children aren't exposed to enough dirt or germs to condition their immune systems.

Regardless of the cause, the rates are high: Some 17.7 million adults in the U.S. have asthma (7.4 percent of the adult population), as do 6.3 million children (8.6 percent of the child population), according to the Centers for Disease Control and Prevention (CDC). And the one thing that has consistently been associated with increased rates of asthma (and other health issues) is pollution — whether in the air or water sources. On World Asthma Day 2016, which falls on May 3, let’s remember that fighting one of the roots of the problem may prevent future asthma diagnoses.

The Clean Air Acts enacted in the 70s and 90s had a positive impact on U.S. air pollution, reducing carbon monoxide, nitrogen oxide, and sulfur dioxide emissions by nearly half decades later. But as highlighted by the recent water crisis in Flint, or the unusually high air pollution levels in Detroit, the U.S. isn't as safe as we might expect. Low-income and minority communities in places like Detroit and Flint, in particular, are often at highest risk of environmental toxin exposure, making their inhabitants more likely to develop chronic health conditions like asthma, ADHD, stroke, chronic stress, and neurological disorders.

That’s because pollution can actually change your genes. Constant exposure to environmental toxins modifies genes, and causes lung damage or asthma to be passed on to next generations. Babies in Fresno, Calif. (the most polluted city in the U.S.) and Detroit are often born with asthma and other pollution-related health issues. And pregnant women who are exposed to air pollution may give birth to babies with asthma or other health problems.

Of course, as asthma rates increase, so do the number of new asthma treatments. In a recent study, researchers developed a new method to prevent asthma and allergies by sneaking allergens into the body inside biodegradable nanoparticles. These hidden allergens wouldn’t cause the immune system to react against them, but instead would condition it to recognize it as a normal visitor and not a foreign agent. But new medical treatments and technologies still don’t solve the root issue of air pollution.

If we’re able to reduce air pollution and environmental toxin exposure, it’s likely that the rates of asthma, respiratory illnesses, and other health issues among children in poverty and U.S. adults in general will decrease. A recent study found that a 47 percent reduction in ambient air pollution resulted in a 32 percent decrease in bronchitis symptoms among kids with asthma, hinting that we can make a difference. On World Asthma Day, let's be aware of the impact humans have on the environment, and know that we have to work together in order to reduce it. Otherwise, our health will suffer for generations to come.