Brain Tumor, Air Pollution Link Sought

Dr. Julia Ljubimova found something disturbing when she probed the brains of rats exposed to air pollution: The dirty air appeared to trigger changes indicating the earliest stage of brain tumors.

The oncologist and researcher at Cedars-Sinai Medical Center in Los Angeles stressed that she isn't ready to say air pollution is a cause of brain cancer.

"I don't want to scare anyone, because this is preliminary data," Dr. Ljubimova said. "But we found something very important."

Her work suggests that fine particles such as those found in diesel soot can switch on the tumor genes that many people inherit, jump-starting the disease process that results in brain tumors.

Hundreds of studies have linked air pollution to early deaths, heart attacks, reduced lung function, lung cancer and various other health problems. Dr. Ljubimova is among a handful of scientists who are focused on finding out what air pollution does to people's brains.

The first results from the fledging research field are creating concern. In addition to Dr. Ljubimova's work:

• A University of Southern California epidemiologist reported to air pollution regulators last year that children living in Southern California's more polluted areas had a higher risk of developing brain tumors.

   

• A University of California Irvine toxicologist reported last month at a Society of Toxicology meeting in Seattle that mice exposed to air pollution in central Los Angeles had brain inflammation and cell injuries associated with the first stages of diseases such as Alzheimer's and Parkinson's.

   

• Last year, Danish researchers monitored brain waves of people exposed to diesel exhaust and found that the pollution increased brain-wave activity, suggesting pollution might alter brain function. Their research was published last month in the journal Particle and Fibre Toxicology.

The findings so far don't prove that air pollution causes brain disease, "but it is intriguing and worrisome," said Roberta McKean-Cowdin, the USC epidemiologist who analyzed health data to find an apparent correlation between pollution and brain tumors in children from newborns to age 5.

Dr. Keith Black, who is the chairman of the Cedars-Sinai neurosurgery department and oversees Dr. Ljubimova's project, hopes the work will lead to discoveries that will allow doctors to prevent or treat the disease. The research also could identify specific particles in diesel exhaust or other pollution that cause cancer, allowing development of engines that don't emit those particles.

Brain cancer, which can destroy the mind and body simultaneously, killed an estimated 12,700 people in the United States last year.

"It is a lot easier to prevent the formation of cancer than it is to treat cancer," said Dr. Black, who has performed more than 7,000 brain cancer surgeries.

Originally published by The Press-Enterprise (Riverside, Calif.).