Olympic athletes preparing for the games in Beijing are worried about the impact of the city's air pollution on their athletic performance -- and their health.

Fragranced laundry products and air fresheners emit dozens of different chemicals, including some regulated as toxic or hazardous under federal law, according to a new study.

Chronic heartburn may alter the immune system and raise the risk of asthma, according to a new study that helps explain why so many people with asthma also suffer from gastroesophageal reflux disease (GERD).