| Kimberly Gray on "Lead in Edible Urban Plants" |
Edible plants grown in urban gardens could contain dangerous amounts
of lead, according to a study by Kimberly Gray, associate professor of
civil and environmental engineering at Northwestern University. Gray
says her study shows that lead in plants is a significant problem in
Chicago.
Gray: Urban gardens in the city of Chicago are often contaminated with
lead, particularly if those gardens are located near a structure, in
the drip
line of a house or garage. And because of that contamination by lead
of the soil, certain plants can incorporate the lead into the edible
portions of the plant tissue.
According to Gray, there are numerous health risks associated with lead.
Gray: Children are extremely susceptible to the effects of lead. Lead can diminish
intelligence. Lead hinders and interferes with the development of the
neurological system. Lead also promotes behavioral difficulties. And
what we showed in my study is that the ingestion of certain leafy green
vegetables and herbs, if grown in contaminated soil, could result in
storing lead in the body.
Gray links many factors to the high lead levels in soil.
Gray: Primarily the lead is thought to be associated with deteriorating paint.
A second source of lead is from atmospheric fallout. It is deposited
on a roof and then in a rainfall it is washed off the roof and is typically
deposited near a building. I think it is just a function of that many
of the paint companies that used lead for so much of the 20th century
were located in Chicago so there might have been a higher use of lead
based paint.
Gray says lead contamination in plants is a problem in many cities.
Gray: There are other cities where there are also hazards. I think Baltimore
is one, Philadelphia is another, Boston. There are areas in, I think
Oklahoma, where some cities have extremely high levels of lead in their
soil. Chicago was, and maybe still is a little bit, an industrial city
so there was industrial sources of lead and then in general the use of
leaded gasoline also until the 80s is another source of lead.
Gray suggests people take several steps to reduce the amount of lead
in their plants.
Gray: You should have the soil in your yard tested. You want to know what the
lead levels are in your yard. You then want to find the area that has
the lowest lead levels to locate a garden and that is typically away
from any building. You may want to resort to container gardening, a raised
bed for instance, and locate it above the surface of your yard.
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