Quantcast

Air Pollution Linked to Genetic Changes in the Brain

Health + Wellness
The Los Angeles, CA city skyline on Sept. 18, 2016. prayitnophotography / CC BY 2.0

By Jason Daley

There's little question that air pollution is toxic for the human body. Studies have shown that particulate matter in the air can lead to lung disease, heart disease, strokes, and lung cancer. But researchers thought the brain might be protected due to the blood brain barrier—a natural system that filters out foreign substances and certain neurotransmitters before they circulate in the brain. A new study from researchers at Cedars-Sinai Medical Center in Los Angeles shows that many heavy metals found in the air may make it into brain tissue, and those pollutants are activating genes that may lead to cancers or neurodegenerative disorders.


To understand how air pollution impacts the brain, doctor Julia Ljubimova, director of the Nanomedicine Research Center at Cedars-Sinai, produced air with the same chemical makeup as that found in Riverside, California, in the Los Angeles Basin. She and her team then subjected rats to the air, with different groups of rats breathing the polluted air for two weeks, one to three months, and 12 months. After examining the rodent brains, the researchers found higher than normal concentrations of heavy metals including cadmium, cobalt, lead, nickel, vanadium and zinc accumulated in the rats exposed to the pollution for a month or more. Even more disturbing, coarse particles of the pollutants had switched on certain genes. The research appears in the journal Scientific Reports.

"Initially I was even skeptical we could find anything. For example, a smoker has to smoke 20 years to develop lung cancer," Ljubimova said, "so I was not sure that in three, six, or 12 months of exposure we would detect changes in these animals' brains at the genomic level. I was very, very surprised when we found so many changes."

So how are these heavy metals making it into the brain despite the blood brain barrier? The coarse particulate material gets in through the lungs, which absorb the pollution particles into the bloodstream and may somehow beat the blood brain barrier, which can weaken due to high blood pressure, inflammation and other stresses. Particulates inhaled through the nose have a more direct route into the brain through the olfactory system and may accumulate through that pathway. Once in the brain, the metals cause inflammation, switching on certain genes including those that cause both benign and malignant tumors, and others that are suspected of causing neurodegenerative disorders like Parkinson's, ALS, Alzheimer's, and other types of dementia—something that other recent studies have also found.

There are still many questions the study can't answer. For instance, do these heavy metals accumulate throughout a lifetime, or can the body flush them out? And most importantly, can a study on rats translate to humans? While Ljubimova said it's likely that the same systems are at work in humans and rodents, her team is also studying Cedars-Sinai's archive of human brain tissue to see if there's evidence of these coarse particles accumulating in the brains of people who lived in areas with air pollution.

Ljubimova said that while the pollutants in her study were based on Los Angeles, she guesses many of the same effects are happening in cities across the world with similar loads of coarse pollutants. The hope, she said, is that the study and future follow-ups will galvanize policymakers to take a closer look at the health impacts of industry, auto emissions, agriculture and military activities in L.A. and other areas with pollution problems. She pointed out that more and more people are being exposed to questionable air as urbanization expands, and scientists don't know all the possible organs and ill effects exposure can cause.

"We thought that nature protected the brain through the blood brain barrier," she said. "But now we see that no, air pollution affects even isolated and protected organs such as the brain. This is important information for thinking about new developments and ways to protect the public."

Reposted with permission from our media associate SIERRA magazine.

EcoWatch Daily Newsletter

Europe is bracing for a second heat wave in less than a month. TropicalTidbits.com

Europe is gearing up for another extreme heat wave that could set all-time records for several European countries.

Read More Show Less
Modern agricultural greenhouses in the Netherlands use LED lights to support plant growth. GAPS / iStock / Getty Images Plus

By Kevin M. Folta

A nighttime arrival at Amsterdam's Schiphol Airport flies you over the bright pink glow of vegetable production greenhouses. Growing crops under artificial light is gaining momentum, particularly in regions where produce prices can be high during seasons when sunlight is sparse.

Read More Show Less
Sponsored
Golde Wallingford submitted this photo of "Pure Joy" to EcoWatch's first photo contest. Golde Wallingford

EcoWatch is pleased to announce our third photo contest!

Read More Show Less
On Oct. 4, 2017, the Senate EPW Committee held a hearing on Wehrum's nomination. EPA / YouTube screenshot

The U.S. Environmental Protection Agency's (EPA) former head of the Office of Air and Radiation who was instrumental in drafting policies that eased climate protection rules and pollution standards is under investigation by a federal watchdog for his dealings with the fossil fuel industry he was supposed to be regulating, according to the New York Times.

Read More Show Less

It's no secret that the Trump administration has championed fossil fuels and scoffed at renewable energy. But the Trump administration is trying to keep something secret: the climate crisis. That's according to a new analysis from the watchdog group Environmental Data and Governance Initiative (EDGI) who found that more than a quarter of the references to climate change on .gov websites vanished.

Read More Show Less
Sponsored
Pexels

New York is officially the first state in the union to ban cat declawing.

Read More Show Less
People walk in the Shaw neighborhood on July 20 in Washington, DC, where an excessive heat warning was in effect according to the NWS. Alex Wroblewski / Getty Images

By Adrienne Hollis

Climate change is a threat multiplier. This is a fact I know to be true. I also know that our most vulnerable populations, particularly environmental justice communities — people of color and/or low socioeconomic status — are suffering and will continue to suffer first and worst from the adverse effects of climate change. Case in point? Extreme heat.

Read More Show Less
Pixabay

By Anne Danahy, MS, RDN

Coconut is the fruit of the coconut palm (Cocos nucifera).

Read More Show Less