Research found that long-term exposure to high levels of air pollution may elevate the risk of developing lupus and other autoimmune disorders

Researchers Uncover Surprising Connection Between Air Pollution and Lupus Experts explain the connection and recommend precautions

Research found that long-term exposure to high levels of air pollution may elevate the risk of developing lupus and other autoimmune disorders

• Long-term exposure to harmful levels of air pollution can increase the risk of developing lupus and other autoimmune disorders, research found.
• Experts say genetics and environmental exposures likely work together to trigger autoimmune diseases.
• While greater air quality regulation is necessary, you can take precautions to protect yourself, like wearing a mask outside during heightened exposure.

Poor air quality from wildfires, vehicle exhaust, factories, and other sources takes a toll on lung health—but mounting research suggests that breathing unhealthy air can also put people at a greater risk of developing autoimmune diseases.

In particular, a study published this summer in the journal Arthritis & Rheumatology found that long-term exposure to air pollution may trigger lupus, a chronic autoimmune disease.

Nearly 40% of Americans—more than 130 million people—live in places with unhealthy levels of air pollution, according to the American Lung Association’s latest “State of the Air” report. That’s an increase of nearly 12 million people compared to last year’s report.

It’s estimated that 50 million people in the U.S. have an autoimmune disease, and the prevalence and incidence of these conditions increase annually.

The exact causes of autoimmune diseases—which include systemic lupus erythematosus (SLE), the most common type of lupus, as well as rheumatoid arthritis—are still a bit of a mystery. But experts believe genetics and environmental exposures such as air pollution may work in tandem to trigger the diseases.

“A lot of evidence is showing that in some diseases, like arthritis, air pollution might be the most important factor contributing to the disease, but not the only one,” Giovanni Adami, MD, PhD, a rheumatologist at the University of Verona in Italy, told Health.

Here’s what experts had to say about the connection between genetics, air pollution, and autoimmune diseases, plus steps you can take to reduce your exposure to unhealthy air.

What Does Research Say About the Air Quality and Autoimmune Diseases?

For over a decade, researchers have pointed to the fact that there’s some connection between air pollution and autoimmune diseases.

Prior research has cautioned that air pollution seems to disrupt the immune system, lead to systemic inflammation, and cause changes to cells, all of which could explain its link to autoimmune disease.

In 2022, Adami and colleagues authored a study that found that exposure to poor air quality was associated with a greater risk of rheumatoid arthritis, inflammatory bowel disease, and connective tissue disorders, including lupus.

Building off of that finding, this new study from researchers at the Huazhong University of Science and Technology in China was aimed at the link between SLE and air pollution specifically.

The team analyzed data from nearly 460,000 people in the U.K. Biobank cohort. Looking at participants’ locations, the researchers measured the amount of nitrogen dioxide, nitrogen oxides, fine particulate matter (measuring 2.5 micrometers or smaller), and particulate matter (measuring 10 micrometers or smaller) each person was exposed to.

After an average of nearly 12 years of follow-up, about 400 people had been diagnosed with SLE.

The researchers’ analysis showed that people exposed to air pollution were between 13% and 27% more likely to develop SLE. Those who had both a genetic predisposition to the disease and high exposure to air pollution were most at risk.

In fact, compared to people with low genetic risk factors and low air pollution exposure, people with the highest genetic predisposition and highest exposure had a 316% to 461% greater risk of SLE.

Genetics Set the Stage, Environment Increases Risk

Of course, exposure to air pollution alone doesn’t determine whether a person will develop SLE or any other autoimmune disease. Usually, it builds upon some existing genetic risk.

“Genetic factors set the stage for the onset of most diseases, including SLE,” said Sasha Bernatsky, MD, PhD, a rheumatologist and a senior scientist at the McGill University Centre for Health Outcomes Research.

Even if lupus doesn’t run in a person’s family, she explained, they may still have genetic risk factors for the autoimmune disease. “Most people with SLE don’t have a family history of SLE or any clear genetic factor that we can easily detect,” Bernatsky told Health.

Gender may also play a role—biological women account for about 90% of lupus cases, so experts posit that estrogen or specific genes on the X chromosome could also play a role in the development of the condition, Adami explained.

When people with these specific genetic risk factors are then exposed to environmental toxins—including air pollution, cigarette smoke, certain viral infections, or lack of vitamin D—it could be a tipping point in determining who develops an autoimmune disease.

“It may be that we all have some genetically driven immune system factors that could put one at risk for SLE, rheumatoid arthritis, or another condition,” said Bernatsky. “Usually each individual genetic factor only contributes a little bit to SLE risk. Then, it takes a multitude of environmental exposures for an individual to ultimately develop SLE.”

Experts still don’t know exactly what causes lupus. But in the case of lupus that develops later in life, for example, it could be that genetic risk factors are aggravated by environmental factors “until finally there is some ultimate trigger, like a viral infection, that stimulates the immune system to produce enough antibodies to create the disease spectrum that we call SLE,” Bernatsky explained.

“The most common hypothesis is that you have two or three factors for the disease,” added Adami.

Protecting Yourself from Autoimmune Disease Triggers

Not all air pollution causes the same amount of damage to human health. Tinier particles, 10 micrometers or smaller, have been shown to penetrate deeper into the body, potentially causing more issues. And ammonium, a chemical used in fertilizers, has experts concerned about its ability to trigger rheumatoid arthritis.

Better understanding how different types of air pollution affect autoimmune disease risk—and enacting policy to reduce exposure—is a good place to start.

“The findings can inform the development of stricter air quality regulations to mitigate exposure to harmful pollutants, thereby reducing the risk of lupus,” Yaohua Tian, PhD, one of the new study’s authors and a researcher at the Huazhong University of Science and Technology, said in a press release.

This air quality regulation will be especially important, as climate change is also increasing exposure to harmful levels of air pollution and creating more opportunities for wildfire smoke to fill the air.

“We really need to understand how climate change-related factors are altering air pollution and how that affects rheumatic disease risk and prognosis,” Bernatsky said.

Beyond these large, systemic changes, it isn’t always easy for individual people to avoid unhealthy air. This is especially true for low-income and BIPOC people who are more likely to live in places with the most harmful levels of air pollution.

But there are some precautions people can take to avoid exposure, particularly on the job. If you work in mines, with asphalt, or along roadsides, you should wear masks to protect against some of the excess air pollution you’re exposed to at work, Adami said.

“The risk benefits will be more than with COVID for wearing masks,” he said. “That’s a very easy thing to implement, but nobody is doing it.”

Julia is a news reporter and editor for Health, where she covers breaking and trending news on health and wellness topics. Her work has been featured in The Heights, an independent student newspaper at Boston College, and Minnesota Monthly.

This story originally appeared on: Health News - Author:Kaitlin Sullivan