Early research shows fine pollution particles can enter the brain directly through the nerve structure associated with smell. They can cause inflammation in nasal tissues and the lungs, which can release chemicals that affect brain chemistry. And researchers say they can also be absorbed through the skin. Experts say they need to do more research to learn exactly how these different transmissions work.
We're still learning about the damage these pollutants can do. In this new study, subjects in Asia with long-term pollution exposure scored lower on verbal and math tests. In earlier studies, brain scans showed pollution can cause the brain to shrink or increase the risk of silent strokes, which don't show any symptoms.
These particles are tiny — a quarter the diameter of a single hair or smaller. Protecting from exposure can be complicated and expensive, but there are some things anyone can do to protect themselves. Experts suggest staying indoors, making sure door and window seals are airtight, and getting a high-efficiency particulate air, or HEPA, filter. They also recommend avoiding vigorous exercise outside during smog alert days.