How can we reduce the risks of lead exposure?
[Writer] This is research news from UIC, the University of Illinois at Chicago. Today, David Jacobs, adjunct associate professor of environmental and occupational health sciences in the UIC School of Public Health, chief scientist at the National Center for Healthy Housing and former director of the Office of Lead Hazard Control at the US Department of Housing and Urban Development, talks about the effect of lead on the body, what happened in Flint, Michigan and what should be done to reduce the risk of exposure to lead hazards. Here’s David Jacobs.
[Jacobs] Lead is actually one of the best-studied toxic substances that we have. There have been tens of thousands of studies to describe lead toxicology – I have a book chapter in a leading toxicology textbook that describes some of this in further detail, but to summarize, the body basically regards lead as calcium. Calcium is a key aspect of how our nervous system works, how our nerves fire. And so much of the lead that is ingested actually ends up in your bone and if it stayed in your bone it wouldn’t do much harm – but it doesn’t. It leaches out into the blood supply and goes after the target organ. It has no beneficial value unlike other metals like zinc or iron or calcium, and it basically inhibits brain development as well as learning ability. We know that lead is associated with reduced IQ. There’s been a major study here in Chicago by a UIC alumna Anne Evens who showed that there was statistically significant declines in reading and math scores even at so-called lower blood lead levels, going back more than a decade. So schools and education reform is very much at the top of the agenda.
The nation has a good capacity in the form of lead poisoning prevention professionals to both manage the risks in the near term as well as in the long term. What happened in Flint was that that professional capacity was ignored in the interest of short-term cost savings, which have now of course evaporated. So what happened in Flint was the short-term management approach to lead in drinking water, which is basically control of water chemistry, was ignored. They changed the source water and they did not change the water chemistry accordingly, as a result, the lead in the pipes was leached into the drinking water supply and exposed people needlessly. So I think there are two lessons to be learned from that – first, you’ve got to pay attention to lead poisoning prevention professionals, and the science — we know how to control this problem, we’ve been dealing with this now for at least 100 years because the lead industry association and companies like Sherwin Williams were successful in putting lead into a variety of products like paint and water pipes and that has cost the nation huge amounts of money to address it.
But the short answer is we know how to fix this, it’s a question of simply using our professional capacity wisely, paying attention to the professionals, and then acting and funding those professionals accordingly.
Flint- fundamentally it was a penny wise pound foolish sort of thing. We will spend far more correcting that problem in Flint and other cities like Flint than we ever saved.
There are a large number of lead water pipes in Chicago, those need to be gradually eliminated. Some jurisdictions for example have done it as part of street paving operations. What we must not do however, is to do so-called partial pipe replacement so this is where, say, there’s a lead service line going out from the house or school to the main water supply line. What sometimes jurisdictions will do is cut at the property line at the part that is city owned and the part that is privately owned and there are now studies that show that if you do this partial pipe replacement, you will actually increase lead exposures because you’re disturbing the lead in the pipe when you cut it and make the lead available to the water supply. So if you’re going to replace the lead pipes you have to replace all of them whether they are on private property or not from a public health perspective.
One of the other studies that was done most recently here in Chicago, a study that UIC did that I led, involved window replacement in Englewood as well as in Peoria – so a rural area and an urban area. Windows turn out to be the highest source of lead dust and lead paint on them so the expectation was that, and this by the way was State money, it wasn’t federal money in this case, the State provided $5 million to do this pilot program, and we followed the homes for a 1 year period, and we showed, not surprisingly, was that if you replace the windows, not only do you replace the lead dust on the windowsills and window truss, but you reduce it on the floors, and the floors are the surface that children contact most frequently as they crawl around and then put their fingers in their mouths – it’s the primary route of exposure. So that program was shown to work. We did a cost-benefit analysis for that program and showed that there would be a net benefit of about $3 million for an investment of $5 million – that’s your net profit, if you will, so it makes sense financially.
Unfortunately, lead has become ubiquitous in our environment. The data are very good at showing that about 70 percent of the nation’s childhood lead poisoning cases are due to lead-based paint hazards in older housing. And that includes dust – that’s settled dust on horizontal surfaces, as well as deteriorated lead-based paint, and lead in soil. So these are sort of legacy sources, if you will. They are also present in a variety of consumer products, and there continues to be production of new lead-based paint in other countries. So paint is the main source of exposure for any individual child it could be a variety of sources. For example, if the parent works in a battery plant, they can bring some of the lead dust home with them on their clothing, water hobbies… And this is what lead risk-assessors are employed to do — they are detectives, they evaluate a child and a child’s exposure potential, and then act to control those exposures. So unfortunately, what we do in this country is basically continue to chase lead poisoned children instead of identifying and correcting the sources of those exposures before children’s blood lead goes up.
We have the technology to look at housing and other exposure patterns, but we continue to play this reactive game, whether it’s in Flint, or here in Chicago or in other places where we know that there are exposures that are not controlled. But we have not found the financial resources to either address these exposures in the near-term or the long-term and that’s what we need to do if we want to make sure our children grow up to be the best and the brightest that they can be.
Personally, I’m outraged that it takes something like Flint to focus a nation’s attention on this problem. So we should make the most of this, I suppose… if there is a silver lining to be had with Flint, it’s that perhaps the nation finally focuses its attention, and the administration and Congress will provide both the policy and the necessary resources to tackle this problem.
This is one of those diseases for which we have solutions. We know how to prevent this problem. Economically, for every dollar we spend on lead hazard control, we get back at least 17 dollars in benefits – that is actually slightly better than vaccines, which in public health is sort of the gold standard. So we know this works, it makes financial sense – there’s no good reason not to make this wise investment in our children’s future.
[Writer] David Jacobs is adjunct associate professor of environmental and occupational health sciences in the UIC School of Public Health, and chief scientist at the National Center for Healthy Housing. This has been research news from UIC, the University of Illinois at Chicago. For more information on UIC visit www.uic.edu