Just the sight of smoggy, polluted air looming over a cityscape is often enough to make one feel a bit down in the dumps, but apparently breathing in the stuff is only making things worse. Study after study into the effects of air pollution on the human body has turned up a grim laundry-list of associated ills -- such as increased risks of stroke, heart attack, and lung disease -- and now, according to the latest research, it may actually be doing harm to our brains as well, ultimately leading to learning problems and even depression. While the negative effects of air pollution on human respiratory systems is well known, researchers from Ohio State University suspected that inhaling particulate may have some unexpected consequences that go much deeper. To test their theory, the team of neuroscientists exposed mice to the same types of pollution released from automobiles, power plants, and factories, concentrated to levels not unlike those found in many urban centers throughout the world.
What they found was quite alarming. After 10 months in this environment, similar to those faced by millions of people daily, mice showed signs of depression, anxiety, and learning difficulties.
Lead researcher Laura Fonken even found physical differences in the brains of mice exposed to pollution compared to those with clean air, particularly in the hippocampus region of the brain.
"The hippocampus is particularly sensitive to damage caused by inflammation," says the researcher. "We suspect that the systemic inflammation caused by breathing polluted air is being communicated to the central nervous system."
These finding are made all the more disturbing considering just how similar the testing conditions were to real-life air quality in much of the developing world, especially in rapidly industrializing nations like India and China.
"The results suggest prolonged exposure to polluted air can have visible, negative effects on the brain, which can lead to a variety of health problems," Fonken told The Telegraph. "This could have important and troubling implications for people who live and work in polluted urban areas around the world."