Be Green Be Sustainable
With the push to be green and sustainable, many schools are turning to gardening to teach valuable skills to students. Growing giant tomatoes means that you have to pull in some reinforcements. Good sunlight, water, fertilizers and the dreaded pesticides. But something much more dangerous hides in the school garden soil. Something that we though we rid schools of in 1978.
Lead in the School Garden Soil
Lead can be found in many things. In the recent years, lead has been found in lunch boxes, toys, books, paint and many other common household products – think toothbrushes. What you may not have expected is that lead could be found in soil. Naturally occurring soil may contain lead, but typically these levels are below acceptable levels. The problem usually arises when schools purchase top soil or new dirt to begin their gardening programs. This purchased soil may come from areas were lead content was much higher.
80 mg/kg is the limit
The California EPA determined that 80 mg/kg of lead in soil may lead to increased of blood lead levels. While this is a guideline, schools should really seek to have lead levels below this threshold to avoid adverse liability. If you are going to start a gardening program at your school site, you should test your soil first. If you are going to purchase top soil, you should buy OMRI certified products. These can be found at http://www.omri.org/sites/default/files/opi_pdf/brand_new.pdf
You can also look for tested and verified compost at http://www.calrecycle.ca.gov/Organics/SupplierList/SiteListing.asp
School risk managers should consider publishing guidelines for their site’s PTA groups and staff to follow when setting up or maintaining a garden. Consider setting up a list of approved soil products also. In addition, schools may wish to test existing gardens to verify lead levels.