Those sounds echo through the streets of polluted cities. Brown clouds made up of noxious gases, dust, soot and even finer particles hang over buildings and hug the ground. When outside, people can’t help but breathe it all in. And in most parts of the world, windows won’t keep these air pollutants out.
Not all large cities have air pollution like this. But in those urban areas where mountains block the wind from clearing the air, such heavily polluted conditions frequently develop. Mexico City often confronts such pollution. So does Beijing, China. And Los Angeles, Calif. With massive populations, these three cities have huge numbers of cars, buses, trucks and factories spewing pollutants into their air.
“It turned out that in the nose, there is a whole cascade of events. The revealed effects are significant for the development of new methods of thermoregulation, and the solution of a serious problem, the treatment of cerebral edema,” says Mikhail Moshkin. “Nanoparticles are now being introduced into various drugs to increase their efficiency. The data obtained help to understand how the concentration of these particles increases and how they can be introduced into the patient’s body.”
As for further research, biologists plan to study the penetration of viruses, especially influenza. This information is important not only from fundamental science but it is also necessary for the development of preventive measures that contribute to the reduction of epidemics.
The scientists also intend to conduct research involving people in high-risk professions, firefighters and welders, to test the recently discovered method of blocking nanoparticles.
Based on the results obtained, it will be possible to develop mechanisms to protect people from the undesirable effects of such particles.
Hitching a ride through the bloodstream is a long, roundabout way for pollutants to reach the brain. Unfortunately, if pollutants are small enough, they can take a shortcut, notes Alison Elder. She works at the University of Rochester Medical Center in New York. As a toxicologist, she studies how materials can harm the body.
Working with fellow toxicologist Günter Oberdörster, also at Rochester’s Medical Center, Elder tracked the route that nanoparticles take to the brains of rats. Some travel through the blood and cross the blood-brain barrier, she found. Others, however, enter the brain directly through the nose. To get there, the super-tiny toxic chemicals travel along the olfactory (oal-FAK-tur-ee) — scent-sensing — nerves. These line the inside of the nose.
When rats (or people) inhale through their noses, air passes over the olfactory neurons. Odor molecules link up with receptors on these nerve cells. That causes the cells to signal a brain structure called the olfactory bulb. Different nerve cells in the olfactory bulb, called mitral (MY-trul) cells, relay this incoming information about smells to other parts of the brain.