We’ve all heard of lead – whether it’s lead-based paint or leaded gasoline. These applications are now things of the past, but do we still have a lead problem? The Soil Science Society of America explores how the poisonous metal is still present in urban soils.
Blogger Anna Wade explains, “in the United States, risk of lead exposure is becoming more of a thing of the past. In the 1970s, lead-based paint was common, as it increased the paints’ durability and sped drying. It was also used in ‘leaded’ gasoline, which made car engines of that generation (and prior) work more smoothly.”
“Unfortunately, the lead from gasoline was also sent into the atmosphere through car exhaust,” says Wade. “It landed in the soil everywhere. The higher the concentration of cars – like cities and highways – the more lead.”
The EPA mandated a nearly 100% reduction of lead in gasoline in the mid-80s, while the U.S. banned lead-based paint manufacturing in the late 70s. But because of the properties found in the metal, there is still widespread lead contamination in urban soils. It is recommended to get your soil tested before you start gardening in it.
“Once deposited, lead remains strongly bound to clay and organic matter in the topsoil,” Wade says. “Lead is not taken up in substantial amounts by plants, nor does it easily leach or migrate further down in the soil. Instead, this lead remains as part of the reservoir of urban soil and dust, susceptible to resuspension during dry periods.”
