Nader Gets the Lead Out


She said that she had always wondered why it was that when we go to
Mexico as tourists, we can’t eat the fruits and vegetables, but when
they are imported to the United States, they don’t make us sick.  How
is that possible?  Tough standards for imported foods.  Inspections.
Systems and procedures that actually work.  Her point was that it isn’t
impossible for other countries to grow good, safe, organic food, but it
just didn’t seem likely that China was there yet.

But here’s where it got really interesting. Pollan told the story of a guy (a farmer?  I missed a few words at this point, so don’t quote me) who received a shipment of produce (or something) from China that was covered in dirt.  The guy thought, "Hey, I’ve got a soil sample from China."  He had the stuff tested, and it was incredibly high and cadmium, a carcinogen produced mainly in China for various industrial process.

This points out a weakness in the organic program.  There is no requirement that the soil be free of heavy metals, or that the irrigation water be safe.  That’s not just true of imported produce, it’s true here at home, too, where we have our fair share of contaminated soil and water.

And speaking of home, if the thought of cadmium-enriched strawberries convinces you that the real solution is to grow your own, consider this article published a few years ago in Science News.  It reports that the soil in vegetable gardens in Chicago had surprisingly high levels of lead.  Consider this:

The Environmental Protection Agency considers 400 ppm lead as the
upper concentration that might be safe for dirt in which children play.
The Northwestern engineers found that more than 75 percent of the
garden soils they sampled had contamination exceeding this
concentration. In many of the tested gardens, lead tainting ranged from
1,000 to 4,500 ppm.

"You’d have thought that lead levels that are so toxic to
humans would stunt the growth of plants," Gray says. "But they don’t."
Indeed, in many of the most contaminated gardens, plant growth was
lush. What this means, she says, is that there’s no way a homeowner
will know whether the heavy metal is present—short of sending the soil
out for testing.

Moreover, the researchers had suspected that soil adjacent to
painted, wood-exterior homes would have higher lead concentrations than
soils around brick apartment buildings do. In fact, Gray’s team found
no difference. She now suspects that this is because even brick
buildings have substantial painted trim and their yards are subject to
lead fallout from fossil fuel combustion.

This is no idle issue for a handful of urban gardeners–none other than Ralph Nader has taken up the cause of testing gardens for lead.  Check out his piece on a new initiative to test the soil in community gardens in Connecticut.  As he says:

This is not a fishing expedition. Preliminary findings, in 2006, have
already shown elevated levels of lead, arsenic and other heavy metals
in soil samples taken from 12 out of 17 initial collection sites,
compared with background levels. Three of these sites exceeded the
state lead guidelines, while one of them reached the definition of a
hazardous waste site.

Lovely.  Anybody had their soil tested for heavy metals?  Anyone?  Anyone?


  1. Indeed, very interesting. As a dedicated vegetable gardener, I think I will have my garden tested for heavy metals. I’ll report back results later. Now, I just need to figure out where to send a sample for testing!

  2. Yes, here in Chicago the Master Gardeners are taught to have soil tested for heavy metals especially lead. We are also advised to grow food in rasied beds. Root vegetables and leaf vegetables are grown in containers. The safest portions of plants is the fruit(squash,tomatoes,beans,berries apples etc…)as heavy metals are trapped from roots up filtering.
    When I first learned that lead in the plants would still be in the compost it made me wary of buying compost even though one supposes it
    is tested how do you make sure? Test every source yourself? It is a worry.
    There is a lot of information about bioremediation of soils, of burning plant material and removing metals from the ashes,that sort of thing. Sounds expensive but is often the only solution when cleaning up contaminated areas and less expensive than removing all soil and replacing although time must be considered.
    It is always something…

  3. Yes, this is a complex problem. There’s crap in our water… there’s crap in our soil… there’s crap leaching from our hoses… and plants have the ability to uptake certain crap… what’s a gardener to do?

    I guess all we can do is keep seeking information in order to take the safest route we know of at the time, whether it be the produce aisle at Whole Foods, the local farmers’ market, or our own backyards. Choosing organic versus conventionally grown is a good start, but there is some blind faith involved. Improved certification standards and monitoring would be a big help to the consumer, so let’s do all we can to support those agencies.

    It should be a given, though, that any organically certified farm should have been given a green light on their soil and water. And hoses? And compost? And manure? And fertilizers? And the health conditions for their workers?

    I’m reading ‘Blithe Tomato’ right now, which gives a glimpse into the world of farmers’ markets. Interesting stuff and a fun read. In revealing different farmers’ personalities, you will learn that not all market booths are run by honest folks. Not all are run by skilled farmers. We need to learn to judge quality in that arena too, and not just by booth fanciness, exotic-sounding vegetables and high prices.

    There does seem to be a tendency toward black and white thinking when it comes to the purity of organic produce. The reality is probably as grey as the water some farmers are putting on our fruits and veggies.

    Want one more to worry about? Heavy metals in some papers we use as worm bedding! Until all inks are non-toxic, I’m going to stick with coir. Next, I’m sure we’ll learn that coir is radioactive or something. 😉

    Oh, yeah, and we must remain optimistic.

  4. I suppose it’s cynical of me to already not trust anything labeled “organic” unless it’s at my local farmer’s market…

    But heavy metals in the soil — wow a whole new category of things to worry about!

  5. Living in the “mixed-use-industrial” part of Berkeley, CA with machine and automotive shops on two sides on my house as well as a couple of foundries in the neighborhood… I had my soil tested before doing any planting. It was a bit scary to see the lead and mercury as well as the “volitive petrochemicals” levels that existed in my residential backyard soil….

    So my vegetable gardening is all done in large troughs with purchased organic coir based soil. I planted my citrus trees in raised bed isolated from the native clay soil below.

    The rest of the yard is all cacti or bamboo, they don’t seem to care, though I do not eat the tunas or nopals from the opuntia or eat any of the bamboo shoots that are from plants that are in the ground. But I have more than enough of them from my potted plants for both the kitchen and my tortoises…

  6. If you know there’s heavy metals in your backyard soil, you might be expected to disclose that when you try to sell your house…

    Just sayin’.

  7. If you know there are heavy metals in your backyard soil, you might be expected to disclose that when you try to sell your house…

    Just sayin’.

  8. Erm, what’s happening here? Where did the fun go? For me gardening is fun and if I want to be scared I watch a horror movie. Although I’d probably laugh at that too cause I don’t scare that easily.:-)

    Personally I love heavy metal as it is good to headbang too. I’m also into brewing teas and drinking them myself. Herbal teas are mmmmmmmm!

    Anything else? Oh yes, I do love to muck about in the garden, E-coli be d*mned.


  9. If I’m not mistaken, it was the community gardeners in Boston who first took up the cause of heavy metals in urban plots some 20 years ago. There’s been a lot of awareness and some testing in Chicago, as mentioned above.

    Basically, anyone whose property abutts a building that might have been painted with lead paint, or who lives near a heavily trafficked road that might have cars on it using leaded gasoline (when that was still legal) should have their soil tested for lead. And while you’re at it, test it for arsenic as well. (The arsenic test is much more expensive).

    If you’re like me, with a corner lot on a busy street, you will find lead in the soil, much more so as you get closer to the house where paint has been peeling or sloughing off the trim (or siding, as the case may be).

    But where you go from there is a bit problematic, because there hasn’t been that much scientific testing of the effect on fruits and vegetables from lead in soil. The consensus, I think, is that the worst problems come with children actually playing in the soil and putting their dirty hands in their mouths. Next would come soil not removed from vegetables or fruits eaten.

    However, lead typically does not travel into fruits or vegetables in amounts that anyone need worry about. If you have high levels of lead in your soil, you would need to be concerned about where you plant leafy greans, such as chard, that do tend to take up lead. Find a spot in the yard that doesn’t have lead in it, or build raised beds.

    Heavy metals do not go away on their own. I recommend that anyone planning to grow vegetables in an urban setting have their soil tested and act accordingly.

  10. Update:
    I poked around my files since the last comment and it was 30 years ago that community gardeners in Boston first raised the alarm about heavy meatal–especially lead–in soils.

    A number of studies and tests have been conducted around the world, especially in urban areas, to determine how much lead from soil can actually get into vegetables from gardening. Again, the main threat is to children actually getting the soil in their mouths. Root vegetables should be peeled (the heavy metals settle mostly in the peel), other vegetables throughly washed. There some evidence that more harm is done to leafy vegetables from airborn metals, rather than the soil. But do have your soil tested. You may need to take remedial action. In fact, we have a friend here in the District of Columbia who had to completely replace the soil around the local schoolyard because of the presence of arsenic.

  11. I live in Buffalo, NY, and bought an old house 5 years ago, one block from Main St. At the time, I read Linda Yang’s book, “City and Town Gardens”, in which she recommended that if you live near a busy thoroughfare, have the soil tested for lead. I did, and the result was 874 parts per million (ppm) of lead. This is from 80 yrs of leaded gasoline, near the busiest street in the city. More recently, I discovered that 2 blocks from our home, in the late 1800’s there was a lead smelter. Our house is unpainted brick with few windows on that side of the house. I have a flower garden in the ground, but vegetables are planted in pots, which grow very well. The problem is, how do you know purchased soil doesn’t have lead in it, too? The only other alternative is to have all the original soil removed, but it has to be treated as hazardous waste, which is very expensive and difficult. So, we put in raised beds, paved some of it, and keep mulch on the sections where the old soil is still being gardened; very productively, I might add.

  12. Thanks Ed for answering the question I was about to post: But what gets in the food itself? And I’m not surprised that we are not sure. I’m less worried about eating strawberries from my garden than that my toddler loves to eat dirt. And I’m with Susan that we can’t just assume the bough dirt is better.

    In the end, it’s worth knowing more about, but I think the benefits (food, joy, learning, being outside) outweigh the risks. Many other things will kill us first.

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