Heavy metal is more than a genre of rock music. It’s also a public health hazard when it involves human exposure to toxins such as mercury and lead.
Lead exposure poisons more than a hundred children each year in Maine, usually toddlers who live in older homes decorated many years ago with lead-based paints. Most commonly the result of hand-to-mouth ingestion of leaded paint flakes or leaded paint dust, lead poisoning in children is associated with a broad spectrum of learning and behavioral disorders, ranging from diminished IQ to hyperactivity, autism and mental retardation.
Extreme exposure can be fatal.
Statewide, 1 percent of Maine children tested show elevated lead exposure, with a range of 2 percent in Androscoggin County to 0.3 percent in Aroostook County. The rate for Penobscot County is 0.7 percent.
While there is no safe level of exposure to lead, public health officials consider blood tests that show 10 micrograms of lead or more per deciliter of blood to be “elevated” and a health concern. That prompted an effort in recent years to encourage pediatricians and other frontline health providers to screen infants between the ages of 12 and 23 months for lead exposure.
Such testing identified 913 cases of lead poisoning in Maine between 2003 and 2007, with 38 percent of children affected living in five areas: Bangor, Portland-Westbrook, Auburn-Lewiston, Sanford and Biddeford-Saco. Each of those communities is replete with homes and apartments built before 1950, housing that is most likely to harbor walls, doorways and window sills decorated with lead-based paints.
Statewide, about 35 percent of housing was built before 1950. In Bangor, nearly 52 percent is that old.
Eric Frohmberg, a toxicologist, heads up the Maine Childhood Lead Poisoning Program, which identifies housing that may put residents at risk of lead exposure and, for rental properties, prevents exposure by requiring landlords to abate any lead hazards.
“Once we identify a child living in a rental unit who has an elevated lead level, by law the landlord has to abate the unit where that child was poisoned,” Frohmberg said. “We have multiple educational events each year with landlord groups, the message being that you don’t want to wait until a child is poisoned. Once that happens, by law, there will be an inspection. If a lead hazard is found, landlords will have to relocate tenants until it’s cleaned up, on their dime. And landlords are responsible for abatement costs, which can be $10,000 per unit.”
Frohmberg said blood tests identify about 100 children in Maine each year as having elevated lead levels.
“There are treatments that can lower lead levels in a child’s blood, but they do not reverse the effects of lead poisoning,” he said. “They may prevent further long-term issues, but there’s no way to reverse what damage has already been done.”
Frohmberg sees Bangor as one of the lead poisoning program’s success stories due to aggressive educational efforts.
“In 2004, 1.9 percent of children tested in Bangor showed elevated lead levels,” he said. “By 2011, it was down to 1 percent. I attribute that to the work being done in Bangor by our community partners there, who have done a lot of work in terms of encouraging landlords to do both testing and abatement.”
Researchers examining the effects of lead poisoning are now exploring a curious statistical link that associates lead exposure with violent crime rates. It’s research triggered by the environmental reality that the predominant source of lead exposure between the early 1940s and the early 1970s was not paint, but emissions from vehicles burning leaded gasoline.
Various studies summarized in a recent analysis by Mother Jones magazine show that as unleaded gasoline began to replace leaded gasoline, lead emissions plummeted. Over time, so did violent crime rates. Crime rates rose dramatically in the ’60s through the ’80s, and then began dropping steadily, starting in the early ’90s. The two curves are virtually identical, only offset by about 20 years.
“It sounds odd that there would be a link, but there is fairly good evidence that supports that assertion,” David Bellinger, a professor of neurology at Boston Children’s Hospital told the Bangor Daily News. “Inner-city children in Cincinnati were followed until age 27 and, after age 18, when the county’s arrest records were publicly available, it showed that the higher the blood levels of lead, the greater the risk of being arrested for assault.”
Bellinger said lead exposure has been linked to diminished impulse control, reduced IQ and difficulty with accepting delayed gratification.
“Putting all the evidence together,” he said, “there’s a fairly consistent picture correlating the amount of lead exposure with the crime rate. Lead is a pretty bad actor. The more we learn about it, the worse it looks.”