Long-term exposure to air pollution is associated with lower mental acuity, researchers reported in the journal Brain. One reason may be that air pollution causes changes in brain structure that resemble those of Alzheimer's disease. The scientists studied 998 women ages 73-87. Over 11 years, they found that the greater the exposure to PM 2.5, the tiny particulate matter that easily penetrates the lungs and bloodstream, the lower their scores on cognitive tests. MRI results showed that increased exposure to PM 2.5 was associated with increased brain atrophy. "PM 2.5 alters brain structure, which then accelerates memory decline," said Diana Younan, a postdoctoral researcher at the University of Southern California.

Can dogs reveal secrets of human longevity?

Can old dogs teach us new tricks? Scientists are looking for 10,000 pets for the largest study of aging in canines. They hope to shed light on human longevity too. "What we learn will potentially be good for dogs and has great potential to translate to human health," said project co-director Daniel Promislow of the University of Washington School of Medicine. For instance, if scientists find a genetic marker for a type of cancer in dogs that could be explored in humans.

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