Researchers have linked some environmental pollutants with diseases, a decreased life span and signs of premature aging, such as wrinkles and age spots. But can accelerated aging be detected at the cellular level in healthy people exposed to pollutants? Now, researchers in the ACS journal Environmental Science & Technology report that although pollutant exposure can affect two hallmarks of aging in people (mitochondrial DNA content and telomere length), the results are not so clear-cut.