How much information can you get from a speck of purple pigment, no bigger than the diameter of a hair, plucked from an Egyptian portrait that's nearly 2,000 years old? Plenty, according to a new study. Analysis of that speck ...

When air quality worsens, either from the smoke and ozone of summer or the inversion of winter, most of us stay indoors. But for individuals experiencing homelessness, that's not always an option. Researchers document the effect of air pollution on ...