http://www.huffingtonpost.com/2011/03/23/urban-gardens-chemicals-lead-arsenic_n_839485.html
 
"With remnants of once-legal lead paint, leaded gasoline and other pollutants from the nation's industrial past tainting land in U.S. cities, soil researchers warn that the growing number of urban farmers and community gardeners need to test their dirt and take steps to make sure it's safe.

"They point to cities like Indianapolis, where nine out of 10 urban gardens tested by one researcher had problems with lead in the soil. Or the Boston area, where a recent study suggests that even clean, trucked-in soil can end up contaminated, perhaps by windblown dust or dirt splatted by rain, in a few short years.

"Agriculture and other experts say such problems don't outweigh the benefits of urban gardening, but those growing food should make sure their soil has been tested and take appropriate steps to address pollution so their fruits and vegetables are safe."

 
Linda