A few years ago my brother-in-law wanted to start a vegetable garden in the backyard of their Boston home. My sister was pregnant and he wanted to bring some pesticide-free vegetables to the table and (eventually) teach my little niece about photosynthesis, bugs and composting. But his uncle, a chemist, was worried about the quality of the soil given their urban environment, so he took a sample and had it tested in his lab. And the results were extremely worrisome...
The lead content in their backyard soil was at dangerous levels — completely unsafe for growing food and especially for feeding that food to a toddler! Uncontaminated soil levels of lead are typically around 10 ppm. My sister and brother-in-law's lead count for top soil was 454 ppm (parts per million) and for 2" deep soil was 1003 ppm. When he first had the idea of starting a garden, my brother-in-law figured he'd have to work to amp up the nutritional content of the soil, but he never imagined that the soil would actually be dangerous to his health and the health of his family.
The New York Times wrote an article on this very topic a couple weeks ago. Health officials, soil scientists and environmental engineers are cautioning against urban gardening due to the high levels of lead in many urban backyards. Where does the lead come from? It can leech into the soil from paint that's been scraped off houses, old lead plumbing or lead pesticides. In my brother-in-law's case, his uncle surmised his problems were the result of Boston's heavy traffic and years of leaded gasoline and car exhaust.
If you currently have a backyard garden or are planning one, you should have your soil tested first. Check with your local health department or local university (usually in the Environmental Sciences department, or something related). A google search in your area under "soil testing" should bring up some good results. Here are a few testing resources we know of offhand:
Brooklyn College Environmental Sciences Analytical Center: Cost is $20 for a soil analysis.
EarthCo: online soil testing company. Cost is $25.
If your soil is found to have a high lead content, experts recommend covering it it with sod. According to The New York Times, if you're planning on growing edible crops, you can replace the contaminated soil or alkalinize it with lime or compost (although that's unlikely to help that much if your lead level is particularly high). You're better off building raised or contained beds, or starting a container garden, as my brother-in-law did.
Read the whole article at the The New York Times.
Have you had any experience with lead in your garden?
Photo via Flickr member OakleyOriginals licensed under Creative Commons.
© 2009 Apartment Therapy
:( I am glad he found out before he started growing food. This story is really sad with how such an easy activity like gardening can be messed up.
When I was in elementary school I lived in a crowded apartment building around Hollywood. I had it in my mind I was going to make a garden from a small plot of dirt littered in garbage. I cleaned it, tilled the dirt, planted flowers and kept clearing trash out when it would appear. I just figured drunks were peeing on my flowers and compacting the soil. Nothing grew. Now I wonder how contaminated the plot was?
view kmarie's profile
Why risk growing vegetable in contaminated city soil when there is a better way that is risk-free? Use sub-irrigated box, bed and bucket planters rather than in-ground planting. Grow vegetables on rooftops, balconies, patios, driveways and other paved surfaces with six or more hours of sunlight
Sub-irrigated (aka "self-watering) planters are the safe and proven way to produce more vegetables per square foot while saving water and your valuable time; no rototiller, shovels, hoes or rakes required. They are the green way to grow green in the city.
view Greenscaper's profile
What about growing mushrooms on the land for a year first? I heard something about how mushrooms are great at breaking down and metabolizing heavy metals and other toxins.
view piffdos's profile
planting edibles in lead-contaminated soil does not automatically mean you will get lead poisoning. lead travels through soil and plants differently. for example, some plants actually uptake lead at higher rates than other plants in the same soil. some of these plants are being studied for bioremediation efforts - with the hopes that they will remove lead for a healthier soil. some plants, such as herbs, are less susceptible to uptaking lead than other plants, such as fruits. it is definitely worth getting a soil test. i've found that soil tests from arlington, illinois are extremely thorough and even have recommendations for the types of plants you hope to establish. self-watering containers are a nice, worry free way to go. for example, you don't really have to worry about weeds in a self-watering container. however, be careful with them. when you add potting mixes to containers, be aware you are generally adding sterile mixes. plants need beneficial bacteria and insects to grow. one way to help establish healthy bacteria in a container is to add compost. one product i love is a fertilizer called peace meal. if you look at the side of the box, you will see it has tons of beneficial bacteria. one other thing: landscape fabric, like the type of fabric used on green roofs, prohibits roots from penetrating. i believe that if you lay that fabric over dirt, then mound clean soil or compost over it, you will not have many problems with lead uptake by plants.
view pedalpowered's profile