Wednesday, May 5, 2010

Detroit's Lead Dilemma

When everyone talks about revitalizing Detroit, right-sizing the city, and creating urban homesteads, they plan for at least some urban agriculture to fill in. UAID loves this idea and sees it as a potential solution to Detroit's food system issues. However, there are obstacles to be overcome before large scale urban agriculture becomes reality.

One obstacle that UAID is particularly interested in right now is heavy metal toxicity in the soil. Because of Detroit's industrial past, there's a lot of stuff in the soil that doesn't exist in rural environments. One heavy metal that's of special concern is lead. It's common knowledge that Superman's powers were affected by lead - turns out humans are affected too. According to the EPA, if not detected early, children with high levels of lead in their bodies can suffer from damage to the brain and nervous system, behavior and learning problems, such as hyperactivity, slowed growth, hearing problems, and headaches. Adults are also affected, with symptoms such as reproductive problems (in both men and women), high blood pressure and hypertension, nerve disorders, memory and concentration problems, and muscle and joint pain.

Detroit's lead levels come mainly from leaded gasoline (and is therefore prevalent everywhere that lots of cars were driven, which is . . . everywhere) and lead-based paint (a problem in older houses if children live in them and eat paint chips or if the houses are demolished and the paint isn't properly managed). 3.8% of children in Detroit have lead poisoning (and since there's no real threshold where lead starts to have effects, any child with lead exposure could have some symptoms). This seems fairly low until you consider that this is three times the state average percentage and means that in a class of 25 children, at least one is likely to have lead poisoning. Remember all those things that lead poisoning did, like causing brain damage, behavior problems, and learning difficulties? Imagine trying to succeed in a school environment already behind because of lead poisoning.

Obviously, we don't want to increase levels of lead poisoning by feeding people produce contaminated with lead. However, there are many questions in this area. Here are just a few:

1. Do plants take up lead as they grow? Do they all take up the same amount? Knowing how much different kinds of plants will absorb lead can help us decide how much remediation to do and which kinds of crops to grow.

2. Are typical methods of remediation applicable to this situation? Typical methods may involve removing contaminated soil and replacing it with clean soil.

3. What other methods are available for remediation? Could we use phytoremediation (plants that take up lead, thereby removing it from the soil) or vermiculture (worms have filtered soil for thousands of years - perhaps they can remove lead)?

The good news and bad news is that there's much we don't know - which means that we need to learn a lot, but there's potential for a solution. And on the plus side for the D, if they find it, other cities can use it, which will show the world that Detroit still leads innovation.

1 comment:

  1. Here's a link to an article that projects hope in "brownfield" (contaminated soil) areas: