We Were Warned

Health: 7 things we were warned to avoid in 2011 - The Week

3. Household appliances may cause asthma. Pregnant women with the highest exposure to low-frequency electromagnetic fields, or EMFs — which are generated by microwave ovens, vacuum cleaners, hair dryers, and other common electrical devices — were three times as likely to give birth to a child who later developed asthma as those with the lowest exposure, a Kaiser Permanente study found. "The problem with EMF is that you can't see, smell it, you can't touch it," says study author De-Kun Li. But you should strive to "avoid those sources that we know about," especially if you're expecting.

4. Staring at a screen before bed ruins your sleep. A National Sleep Foundation study found that 95 percent of Americans gaze at some kind of light-emitting electronic device — be it a smartphone, tablet, computer, or TV — less than an hour before bed, which keeps the brain from releasing the sleep-inducing hormone melatonin. Young people, the heaviest gadget users, are the drowsiest, and their habit "may have serious consequences" for their health, says study author Lauren Hale. Sleep deprivation causes 100,000 car wrecks and 1,550 traffic deaths per year.