Cell phone towers have become ubiquitous near residential areas in the U.S. and abroad, but precautions should be taken in siting the towers because of possible health risks, according to a report in the Canadian journal Environmental Reviews.

The report by University of Washington research professor Henry Lai and environmental journalist Blake Levitt notes that exposure to the radiofrequency radiation emitted by cell phone towers has been linked to a variety of health problems, including decreased libido, headaches, vision problems, and even cancer.

Though the evidence is inconclusive and, in some cases, contradictory, they say it warrants a requirement that the towers be at least 150 feet tall and separated from residential neighborhoods by at least 1,500 feet. Regular radiation monitoring of the installations should also be considered, they say.

Part of the difficulty in addressing the problem is that global society is so dependent on wireless technology, the authors say. Some 5 billion people worldwide use cell phones, while more than 280 million Americans are subscribers. Servicing this demand requires an extensive infrastructure: there are more than 250,000 cell phone towers in the U.S., up from fewer than 20,000 in 1995.

A comparable spike in the number of antenna supporting Wi-Fi and related technology is likely in the foreseeable future.

The present challenge is compounded by the fact that the U.S. has never invested in a comprehensive study of possible health effects from living near cellular towers.