Indoor air pollution is a serious problem in developing nations because of stoves, secondhand smoke, dust mites, mold, bacteria, cleaning products, and more. These sources release volatile compounds. The most studied indoor air pollutant is nitrogen dioxide (NO2). These pollutants can harm women and small children who spend most of their time at home.

Scientists finally reveal a complete picture of the areas that the immune system attacks to cause type 1 diabetes.

The Zika virus may be particularly adept at entrenching itself in parts of the body that are shielded from the immune system, making it harder to fight off and possibly lengthening the timeframe in which it can be transmitted, top US experts say.