Public health warnings are aimed at the many to help the relatively few avoid a problem. Daily, heavy exposure to chemicals may be dangerous, however. If a pregnant woman must work around fumes or chemicals, such as in a dry-cleaning business, art studio, or factory, she should use gloves, masks and adequate ventilation. But if she just gets a whiff of dry-cleaning fluid while picking up her laundry from the cleaners, there's little need to worry, Leavitt says. Some environmental toxins such as lead are best avoided at any time, but especially during pregnancy.
Radiation is also dangerous to developing babies.
A pregnant woman who works in an x-ray department of a hospital must take precautions to avoid exposure. Taking hot baths, using saunas, or exercising in hot, humid weather can raise a woman's core temperature and have the potential to cause birth defects, especially in the first trimester. Lukewarm baths and moderate exercise are fine, however. Although they have at times been accused of causing harm, there's probably no need to worry. Recent studies have not found any relationship between computer terminals and miscarriages.