Health

Washington Post -  Last year, startled scientists reported that the average human brain they studied contained roughly the weight of a plastic spoon in microplastics and nanoplastics. Now, a deeper look suggests a much broader assortment of material from the outside world — silica, metals, soot and other debris — is getting through.

Researchers from the Rush Alzheimer’s Disease Center and other institutions examined, in extraordinary detail, brain tissue from 11 people who died at ages 80 to 91. They discovered that some particles had penetrated deep into the brain, reaching the amygdala, a region that helps shape emotion and memory.

The finding is part of a broad shift in how scientists are thinking about the link between air pollution and conditions that impact the brain such as dementia, Parkinson’s and autism.

For years, a leading explanation has been that pollution harms the brain indirectly, by triggering inflammation and other changes throughout the body. That idea hasn’t gone away. But scientists are now exploring whether that pollution may also act more directly.