Getting the lead out at the White House
By that, I don't mean speeding up the economic stimulus. I'm talking about the traces of lead that were found in the White House Kitchen Garden.
Mother Jones reported that the National Park Service detected 93 parts per million of lead in the South Lawn's soil before the garden was dug. A lead level of 400 parts per million is the upper limit that the Environmental Protection Agency allows for soil in areas where children will be active. In the European Union, the limit is 40 parts per million.
Some media outlets have taken this lead news and added it to the Obama garden bashing arsenal. For urban soil along the Eastern Seaboard, I'd say 93 ppm of lead is pretty low. It's not anything to sing and dance about, but compared to lead levels that are 10 to 50 times higher in large cities, that level presents a small threat. With proper management, gardeners can still grow food in (or on top of) lead-tainted soil.
Lead, believe it or not, is a naturally occurring element in soils. Background levels of lead can range from 15 to 40 ppm, according to the University of Massachusetts. Elevated lead levels that measure into the hundred or thousands of parts per million are the result of a century of industrialization, engine exhaust, and the decay and disposal of lead-based paints.
One other source of contamination is more recent: the application of treated sewage sludge, or biosolids, as fertilizer. This method came into practice in the U.S. in the late 80s after dumping sludge into the oceans was banned. Sludge has been increasingly used as a fertilizer on farms and private landscapes (including the White House) in the years that followed.
Beside concerns about pharmaceutical and chemical residues that can remain in this sludge, EPA guidelines permit sludge lead levels of 300 ppm. Critics of this practice point out that If soil already has lead in it, and sludge with lead (and who knows what else) is laid on top, then the contamination problem is only compounded.
Tom Philpott at Grist suggests that the Obamas have new tests done to measure sludge-borne contaminants. If the soil is acceptable, then the issue (at least on the White House grounds) will be resolved. If not, then the findings could initiate more action and awareness in regard to agriculture and public health.
Which is what this garden was meant to do in the first place, yes?
Mother Jones reported that the National Park Service detected 93 parts per million of lead in the South Lawn's soil before the garden was dug. A lead level of 400 parts per million is the upper limit that the Environmental Protection Agency allows for soil in areas where children will be active. In the European Union, the limit is 40 parts per million.
Some media outlets have taken this lead news and added it to the Obama garden bashing arsenal. For urban soil along the Eastern Seaboard, I'd say 93 ppm of lead is pretty low. It's not anything to sing and dance about, but compared to lead levels that are 10 to 50 times higher in large cities, that level presents a small threat. With proper management, gardeners can still grow food in (or on top of) lead-tainted soil.
Lead, believe it or not, is a naturally occurring element in soils. Background levels of lead can range from 15 to 40 ppm, according to the University of Massachusetts. Elevated lead levels that measure into the hundred or thousands of parts per million are the result of a century of industrialization, engine exhaust, and the decay and disposal of lead-based paints.
One other source of contamination is more recent: the application of treated sewage sludge, or biosolids, as fertilizer. This method came into practice in the U.S. in the late 80s after dumping sludge into the oceans was banned. Sludge has been increasingly used as a fertilizer on farms and private landscapes (including the White House) in the years that followed.
Beside concerns about pharmaceutical and chemical residues that can remain in this sludge, EPA guidelines permit sludge lead levels of 300 ppm. Critics of this practice point out that If soil already has lead in it, and sludge with lead (and who knows what else) is laid on top, then the contamination problem is only compounded.
Tom Philpott at Grist suggests that the Obamas have new tests done to measure sludge-borne contaminants. If the soil is acceptable, then the issue (at least on the White House grounds) will be resolved. If not, then the findings could initiate more action and awareness in regard to agriculture and public health.
Which is what this garden was meant to do in the first place, yes?
posted by mr damon at
1:57 PM
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