EWG News and Analysis

The latest from EWG’s staff of experts >>

Growing veggies in my (leaded?) urban soil

Thursday, June 25, 2009

I live in an old house (1911) and used to work in affordable housing, so the dangers of lead paint aren't new to me. And with toddlers around for years now, I know to avoid paint chips in the mouth and lead dust in the air.

What I didn't connect - until recently - was that there might be lead in our soil, which is where we grow food. And that for those who have backyard chickens (a hot urban trend - at least in my sustainability-obsessed corner of the world), those super fresh eggs can deliver a dose of lead if the chickens are eating it. Yowza.

Since we don't have chickens (yet), I focused on our vegetable garden which just happens to be right behind an old, old garage that had chipped so much paint into the yard it was bare. Ugh.

Two recent articles tell you what you need to know
In May, the New York Times ran an article about a Brooklyn homeowner and avid backyard gardener whose yard is loaded with lead. And just two weeks ago my hometown paper, The Oregonian, ran another - the columnist's own raspberry bushes had visible paint chips under them. Together, they answered all of my questions.

Does it really matter if there's lead in - or near - my vegetable growing soil?
Most probably. While there is some disagreement out there (lack of field data), the general consensus is that it's worth testing and adapting your garden if you have high lead soil levels. Why? Because some soil types and some plants and some lead sources can add up to a hazard worth avoiding. The main concern is lead dust landing on your vegetables, which (happily!) you can just wash off. The less certain concern is uptake from the soil into the plant itself.

What should you do if you're a backyard gardener?
Test your soil. Understand the results, then mitigate if needed. Why test if you think there's no risk? Because according to the Times, environmental engineers and soil experts say "any place" is potentially tainted. Specifically, they list these causes for lead-tainted soil:

Excessive lead in soil is the legacy not only of lead paint but also of leaded gasoline, lead plumbing and lead arsenate pesticides. Although these products were outlawed decades ago, their remnants linger in the environment. Lead batteries and automotive parts, particularly wheel balancing weights, are still widely used and are sources of soil contamination.

Soil is likely to contain high levels of lead if it is near any structure built before 1978, when lead-based paint was taken off the market, or if a building of that vintage was ever demolished on the site. Pesticides containing lead were often used on fruit trees, so land close to old orchards is also of concern. And beware of soil around heavily trafficked roadways; it, too, is probably laced with lead.

I tested our soil for $20 at a local lab (which handles mail orders) and learned that, thankfully, our levels are low enough to keep on keepin' on with the arugula, tomatoes and basil. But if you test and learn that your levels are high, you can mitigate - and keep on gardening. Mitigations range from washing your veggies before eating them (to remove the dust) to building raised beds with clean soil from off site to doing some phytoremediation to clean the soil over time. All do-able, some easier than others.

The good news is that lead need not halt the urban gardening trend - but it needs to be included in your garden plans. Where you're the boss of your food. Isn't that nice?

[Thanks to jefield and Flickr creative commons for the photo]


comments powered by Disqus