But a lead reading of 93 ppm is "ridiculously low" for any urban garden, according to Dr. Gabriel Filippelli, chair of Geology at Indiana University, and associate chair of the Center for Environmental Health.
"It would be nearly impossible to find a garden anywhere with [a lead level] less than 93 ppm," Dr. Filippelli said, and added that it's absurd to claim contamination based on this test result...
This misinformation campaign has slithered around the blogosphere like a viral worm, but the only bit of truth in any of the stories is that the National Park Service did in fact test the White House Kitchen Garden for lead, and did in fact find that lead level reading of 93 parts per million. And Dr. Filippelli maintains that anyone suggesting the garden is contaminated based on a lead count of 93 ppm simply has no idea what he or she is talking about.
Dr. David L. Johnson, professor of Environmental Chemistry, Environmental Science, and Forestry at the State University of New York, agrees with Dr. Filippelli's assessment, and he adds that Washington, DC already has relatively low lead levels when compared to other cities that previously had heavy industry located within their borders. He said that lead testing is a good idea for all city gardens, so appropriate remediation measures can be taken to grow safe food if lead is present. But no remediation of the South Lawn, where the White House Kitchen Garden is situated, was indicated with a test result of 93 ppm.
"I have no concerns at all about growing vegetables in soil with a reading of 93 ppm," Dr. Johnson said...
He added that he and his colleagues recommend the same thing for lead readings of up to 200 ppm. "Most state day care centers identify 400 ppm as the dangerous level for exposure for children," Dr. Filippelli added, to give perspective.
It should be noted that almost every state agriculture extension agency in the US makes the same recommendation--that planting crops in soil with lead levels of between 200 and 400 ppm is no danger to human health.
Dr. Kimberly Gray agrees with both Dr. Filippelli and Dr. Johnson's assessments of the White House Kitchen Garden. She's the Director of the Environmental Sciences Program at Northwestern University, as well as Associate Director of the Institute of Environmental Catalysis, and has spent a lot of research time figuring out remediation solutions for environments that actually are heavily contaminated. She said she's frequently seen areas in Chicago with lead levels between 5,000 and 10,000 ppm. She noted that calling the White House Kitchen Garden "contaminated" based on a lead count of 93 ppm is "about politics, not lead."
"It's inflammatory," Dr. Gray said. "93 ppm is well below background lead for an urban environment. It's what you'd expect just from atmospheric deposition." Atmospheric deposition is lead particles that fall out of the sky, from things like auto emissions.
Dr. Filippelli said that the ppm reading for the White House Kitchen Garden is most likely even lower than the actual 93 level the garden has been tagged with, because not all lead that's actually present in the soil is bioavailable--capable of being absorbed by food crops. Dr. Gray agreed; both have studied the different ways various crops absorb lead.
Facebook
Twitter