Every organ in your body could be adversely affected by air pollution, according to two new papers published in the journal Chest.
The researchers argue that the ultrafine particles that make up air pollution are absorbed by the bloodstream and travel throughout the body, potentially harming every cell in the body. Additionally, the presence of these particles in different organs could cause dangerous levels of inflammation as the body’s immune system tries to fight what it perceives to be infection.
Previously, research into the effects of air pollution have centered on just two organs — the heart and lungs — where the consequences can be readily identified.
The new review, conducted by the Forum of International Lung Societies, looks at existing research to help people better understand air pollution’s health consequences. The team of researchers drew connections between and extrapolated upon various studies.
“The purpose of the paper was to say that air pollution affects essentially every organ of the body,” Dean Schraufnagel, a pulmonologist at the University of Illinois at Chicago who led the new work, told Global Citizen. “Our goal is to impress upon medical societies that if you focus on diabetes, then you also should join the fight for clean air.
“Or if your organization is about liver disease, these toxic things in the air often get into the whole body and then are brought to the liver to be broken down and then they cause fatty liver or prevent the liver from functioning as well,” he added.
An estimated 8.79 million people die prematurely from air pollution each year, and the vast majority of these deaths are related to cardiovascular and respiratory diseases such as stroke and heart disease.
The new papers suggest that this figure might just be the “tip of the iceberg,” according to the Guardian.
Air pollution levels vary around the world, with the highest levels recorded in low-income countries. India, for example, is home to the 14 cities with the highest concentrations of air pollution. More than 90% of the world, however, is breathing dangerous amounts of toxic particles.
The main causes of air pollution include burning fossil fuels, waste-burning facilities, agriculture, air conditioners, and chemical factories, according to the National Resource Defense Council.
While air pollution is generally thought to take the form of clouds of smog, it’s most often invisible. Fine particulate matter, hundreds or even thousands of times thinner than human hair, gets released into the atmosphere from industrial activity.
And humans breathe in these particles, which then penetrate the lungs and bloodstream.
“These particles are so small, sometimes as small as 0.1 microns,” Schraufnagel said. “A cell is about seven microns across, so you can imagine a particle that is that small, when it comes across a big immune cell, the immune cell gobbles it up, then it can get right into the blood stream and is carried to every part of the body.”
Recent research has shown how air pollution can affect the brain by diminishing a person’s intelligence, causing depression, and triggering psychotic episodes. Schraufnagel said that this is because the fine particles enter individual cells, which can lead to inflammation in the area when the immune system attacks the foreign particles.
“White blood cells try to attack and kill these particles, but they can’t because they’re inanimate and sometimes have toxic things like arson or lead on them,” he said. “So particles break down and then the body brings in more inflammatory cells and sets up an inflammatory reaction in the lung, and then these immune cells send out enzymes and mediators that then circulate throughout the body.”
Young children, in particular, are vulnerable to stunted brain development because of air pollution.
Similarly, fine particulate matter in the digestive system can cause inflammatory bowel syndrome and other harmful conditions.
Air pollution has even been shown to harm the reproductive system and adversely affect fetuses.
More than 70,000 studies have already been conducted to investigate the health effects of air pollution, but scientists are just beginning to unravel the many ways it increases mortality rates, Schraufnagel said.
As the impact of air pollution becomes better understood, medical mysteries across fields may someday be attributed to too much exposure to hazardous airborne particles.
“The WHO calls its a silent epidemic because people don’t realize it, and even doctors or medical professionals, they say ‘oh he must have had too much cholesterol or bad luck,’ but maybe there’s been a substantial contribution of air pollution,” he said, about some people who die from heart disease.
“We want to know about the effects, we want to educate others, and we want to advocate,” he added. “We want to make the world a better place and that’s our goal, where people breathe easier and live longer and healthier.”