> people from excessive radio-frequency radiation, the waves of <br />> electric and magnetic power that carry signals. The power isn't <br />> considered harmful by the time it reaches the street, but it can <br />> be a risk for workers and residents standing directly in front of <br />> an antenna. One <br />> in 10 sites violates the rules, according to six engineers who <br />> examined <br />> more than 5,000 sites during safety audits for carriers and <br />> local municipalities, underscoring a safety lapse in the network <br />> that makes cellphones hum, at a time when the health effects of <br />> antennas are being debated world-wide. <br />> The FCC has issued just two <br />> citations <br />> to cell carriers since adopting the rules in 1996. The FCC says <br />> it lacks resources to monitor each antenna. "It's like having a <br />> speed limit and no police," said <br />> Marvin Wessel, <br />> an engineer who has <br />> audited more than 3,000 sites and found one in 10 out of <br />> compliance. On <br />> a sweltering June day in Phoenix, Mr. Wessel strolled through a <br />> residential area near Echo Canyon Park and spotted lawn chairs <br />> near a <br />> cellular antenna painted brown to match a fence. <br />> His monitor showed emissions well above safety limits. After <br />> being alerted by The Wall Street Journal, T-Mobile added warning <br />> signs and roped off a patch in front of the antenna with a chain. <br />> "The safety of the public, our customers and our employees is a <br />> responsibility that all of us here at T-Mobile take very <br />> seriously," said a T-Mobile spokeswoman. At very high levels, <br />> radio-frequency radiation can cook human tissue, the FCC said, <br />> potentially causing cataracts and temporary sterility and other <br />> health issues. To buffer people from these "thermal" effects, <br />> the FCC set two limits for how much RF people can absorb?one for <br />> the general public, and an "occupational" limit five times higher <br />> for people trained to work near antennas. The higher level is <br />> still 10 times below the thermal level. Carriers <br />> have to restrict access near antennas that are above the limits. <br />> Workers and others who venture into hot zones?generally up to 20 <br />> feet in <br />> front of an antenna?must be trained and have RF monitors. Most <br />> cellular antennas aren't strong enough to cause thermal <br />> problems, engineers say, and carriers are installing some smaller <br />> antennas with lower power levels. But some are being made <br />> stronger to meet demand for high-speed Internet access, <br />> high-definition video and other services. A German study in 2013 <br />> found higher emissions from 4G antennas. "The more bandwidth, the <br />