Concerns about power lines and leukemia surface again

An article published in the B.C. Medical Journal has raised awareness again that children living near electrical power transmission lines run a slightly higher risk of succumbing to leukemia.

The article by Ray Copes, MD and Prabjit Barn, M.Sc. of the B.C. Centre for Disease Control was entitled, “Is living near power lines bad for our health?” Its conclusions are of interest to consulting engineers who work in the power sector and land planning sectors.

Copes and Barn noted that since the first study to link childhood leukemia with electromagnetic field exposure (EMF) was published in 1979, later studies have “found weak associations to support this original finding.” From those studies it was estimated the risks only came into play when the child lived within 60 metres of a high-voltage power line of 500 kV.

However, the authors say, a more recent study in the U.K. found that there was an increased risk for children living as far as 600 metres (more than half a kilometre) from the power lines.

The authors say, “Although distance of homes from power lines can be considered a crude measure of exposure, the results of this study do merit attention.”

Still, they add, since the underlying biological mechanism is unknown it’s difficult to determine which measure of EMF is most appropriate for measuring health outcomes.

As well, the risk remains very small. In their estimations for the impact in B.C., based on current population patterns and on a statistical bases, living near power lines would add up to one additional case of leukemia in the province every year.

They conclude that to eliminate any risk would mean locating every residence farther than 600 metres away from a power line, a plan that would require “substantial changes to existing land use patterns and would require significant resources.”

They think those resources could be better spent elsewhere, “… based on best available evidence, one can achieve much greater risk reduction or health benefits if resources are directed to other larger, better established risks.”

The article was in BCMJ, Vol. 50, No. 9, November 2008. See www.bcmj.org