August 21, 2007

A bit more about lead

. . . from Slate today.
The Centers for Disease Control and Prevention consider blood lead amounts under 10 mcg/dl—the amount present in many toddlers—safely below the "level of concern."

As it turns out, according to numerous studies (e.g. The New England Journal of Medicine, April 2003), this sort of level can permanently impair your brain by about 7 IQ points. The scientific community is apparently aware of all this, but the relevant CDC advisory committees have been de-scientisted, and packed with lead industry folks.



Michelle said...

Brandon-seems like this issue is one that's on your mind a lot lately. Here is everything you ever wanted to know about lead-including all available epi and occupational studies (up to 2005, anyway):

I still think we're on the right track-if the Slate article is accurate (re: historic CDC recommendations), the recommended action level for children's blood leads is 25% of what it was when you and I were children in the 1970s, and we were more than likely exposed to leaded paint and ambient lead from gasoline (since they were not yet banned).

Can you imagine how much smarter we would be now if the limit was 10 milligrams per deciliter when we were growing up, and the paint and gas was lead-free?? :-)

My prediction is that as we get more data quantifying more sensitive health endpoints, the environmental guidelines controlling exposures and/or managing elevated body burdens to developmental/neurological toxicants will continue to decline (the trend that we have been seeing for the past few decades for just about everything!).

Jackson, Sheree, & Jason said...

Michelle--we can only hope that will be the case. Unfortunately in the last 7 years, our government regulatory agencies have flipped a bitch on the road to improving public safety. That's a long discussion that I'm not really posting about.

My cousin was diagnosed with lead poisoning. I last saw her at 1 1/2. She was an adorable and bashful, but sociable girl. At 2, her lead levels were tested and found to be well above normal. After a round of chelating agents, they got her levels down into the low 20 mcd/dl region and gave up on the medicine since she resisted taking it and her doctor said it was below the level to really be concerned about. The lead poisoning was sourced to the obvious--paint chips in their historic 100 yr old home (duh. Please don't let your children have access to old, peeling paint) but the lead also turned up in some insidious places. Apparently vinyl mini blinds are often contaminated (similar to the painted bibs?) Their cast iron bathtub was painted with lead, which leached into the bathwater. There were some other sources that I can't recall. Anyway, my cousin was diagnosed with Asperger Syndrome (a high functioning autism). After a few years of intensive therapy and tutoring, she no longer meets the criteria for autism spectrum disorders, but the damage to her brain cannot be undone.
It's inexcusable for the children's products industry and the regulatory agencies to allow tainted products to be sold. I'm disappointed in the media for telling parents not to panic since such a small percentage of products have been discovered to be contaminated (That small percentage is a high 25% of kid's cheap metal jewelry). Parents are right to be outraged, vigilant, and even a little paranoid on this one.

TH said...

Another possible source of lead is solder in your water pipes. A lot of water companies have removed lead service lines, but once the water is to the meter it is the customer’s responsibility. Water providers are required to conduct lead testing at a representative number of customer’s homes, and these samples must be collected before anyone uses the water, and that includes flushing the toilet. If more than 10% of the sample results are above the action level then the water system must take action to make the water less corrosive.

Interestingly enough that still means that some customers could have more than the action level first thing in the morning. Since, I have a great love for historic houses we always seem to live in places that may have some lead solder somewhere, so first thing in the morning I run the water until it is cold. A standard recommendation is to run the water for 30 seconds to 2 minutes.

Also being the worry wart that I am I had my blood tested for lead and mercury while I was pregnant. It is not very expensive to test for metals, so I requested those analyses be run while they were testing my iron levels. My mercury concentration was below the detection limit, and my lead was just above it. Kind of interesting…

Brandon said...

10 mcg/dl is the "legal" limit -- Elliot has been tested, and he is at 3.

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