As the nation wrings its hands about the plight of lead-poisoned children in Flint, thousands of other children throughout Michigan face similar challenges because of exposure to the toxin.

That includes pockets of children in communities ranging from Detroit, to the city of Morenci in Lenawee County, to the tiny village of Nashville east of Hastings.

In 2014, 20 percent of 1- and 2-year-olds tested for lead in Highland Park, 12 percent in Muskegon, and 10 percent in Jackson had a lead level in their blood of at least 5 micrograms per deciliter or mg/dL, the current benchmark of concern set by the federal Centers for Disease Control.

And more than 5 percent of toddlers tested in the cities of Grand Rapids, Kalamazoo and Saginaw had elevated lead levels in 2014.

"It's a real public-health crisis with a real-life impact," said Rebecca Meuninck of the Michigan Network for Children's Environmental Health. "We need to address what's happening in Flint, but we also need solutions for all the children in Michigan."

Even low levels of lead exposure can cause irreversible brain damage in children under age 6. That damage can include a reduction in IQ, increased risk of attention deficit disorder and increased aggression and impulsivity. Studies show children with elevated lead levels are more likely as adults to be un- or underemployed, be dependent on government services and/or end up in prison.

While the problem in Flint is lead leaching into old water pipes, there are multiple ways which children can be exposed to lead. Today, the most common source is living in an old house with lead paint.

"Flint is an anomaly because they screwed up so badly with the water. But lead in the home is what's poisoning our children," said Matt Milcarek, a Kalamazoo city commissioner who also works for Kalamazoo Neighborhood Housing Services.

"It makes me nervous that everyone is focused on water right now, and so people may test their water and think they're safe, when they may not even be remotely safe" from lead exposure, Milcarek said.

It's an issue that's affected Milcarek personally. He and his wife own a century-old home, and their 2-year-old daughter had a elevated lead level when she was tested in 2014. The home has since undergone in $10,000 remediation work paid by a state program to remove lead in old homes where young children are residing.

Economists and other experts say lead remediation is worth the investment considering the costs associated with lead poisoning, both for the individuals personally affected and taxpayers as a whole.

A 2014 study co-authored by Meuninck and researchers at University of Michigan's Risk Science Center estimated childhood lead exposure costs Michigan residents an estimated $330 million annually between decreases in lifetime earnings due to lead-associated IQ loss and increases in crime, health care and special education.

No corner of the state is immune from the impact of lead poisoning.

Lead testing is recommended for 1- and 2-year-olds, and about a third of Michigan children in that age group were tested in 2014, according to data from the Michigan Department of Health and Human Services.

Of the 84,776 Michigan toddlers tested in 2014, 3,141 -- or 3.6 percent -- had elevated levels of lead in their blood.

A total of 77 of Michigan's 83 counties had at least one toddler with elevated levels of lead in their blood. The rural county of Oscoda topped the list of counties in percentage of 1- and 2-year-olds who tested high in 2014.

Database: Lead toxicity in toddlers by county

The good news: There has been a huge drop in children's lead levels in recent decades since the United States phased out use of leaded gas and leaded paint.

In 1976, the average American child had a blood lead level of approximately 16 ug/dL -- a level considered unacceptable today.

Lead levels have dropped even more since. In 1998, 44 percent of Michigan children under age 6 tested had at least 5 mg/dL in their blood, compared to 3.4 percent in 2015.

"We've greatly reduced lead levels. It's been a great public health success story," said Dr. Eden Wells, chief medical executive for the Michigan Department of Health and Human Services. "But even as lead levels are going down, it's still a public health issue."

'Full of lead'

Even today, "a child's environment is full of lead," the CDC website says.

That includes exposure from sources such as paint, gasoline, solder and consumer products and pathways including air, food, water, dust and soil, the CDC says.

The 2014 U-M study estimates 70 percent of lead poisoning cases today in Michigan are linked to lead paint in older homes.

Paint made before the 1940s had lead contents as high as 50 percent -- and that high lead content was marketed as a measure of quality because lead increased duriability.

Homes built after 1940 also can be problematic. It wasn't until 1978 that lead paint was banned in the U.S. and today 40 percent all of U.S. housing still have some lead paint, according to the CDC.

The biggest potential issue in those homes: Aging windows and doors that generate a toxic dust every time they are opened or closed.

The second most-common source of lead exposure today is contaminated soil, a legacy of air pollution from the days of leaded gas as well as lead paint used for home exteriors that has leached into the ground.

Neighborhoods located near old factories also are likely to have lead-contaminated soil from air emissions decades ago. That helps explain why high lead levels in children is so often seen in factory towns such as Detroit, Flint, Saginaw and Hamtramck.

Children get exposed to lead in soil when they're playing outdoors, especially if they're playing in dirt and putting their hands into their mouths. The contaminated soil also can get tracked indoors and incorporated into household dust.

As seen in Flint, lead in water service lines also can expose young children to lead.

In his job for Kalamazoo Neighborhood Housing Sevices, Milcarek said he makes a point of trying to raise awareness about lead poisoning.

"Anytime someone comes in with kids under 6, I'm asking them, 'How old is your house?' " Milcarek said, and he urges them to get their children tested for lead if the house was built before 1978.

He also warns parents that living in a newer home is no guarantee that a child isn't being exposed to lead.

"You can get lead poisoning from eating off glazed pottery or eating venison killed with lead bullets," he said. "There have been kids poisoned by sucking on the lead weights in their dad's tackle box.

"There are so many ways in which a kid can be exposed to lead," he said. "Having your kid tested for lead is the simplest and easiest way" to check their exposure.

No safe level

The CDC says there is no safe level of lead exposure for children.

"Even low levels of lead in blood have been shown to affect IQ, ability to pay attention, and academic achievement. And effects of lead exposure cannot be corrected," the CDC website says.

Children with blood lead levels as low as 3-4 mg/dL have lower scores on elementary school achievement tests, studies show.

In fact, the research indicates that losses in IQ associated with lead exposure are greatest at lead levels below 10 mg/dL.

A child can lose between 3.9 and 7.4 IQ points as his or her lead level increases from 1 to 10 mg/dL. That compares to a loss of an additional 2.5 to 3 points in IQ when a child's lead level goes from 10 to 30 mg/dL.

Low-level chronic exposure may have an even greater effect on IQ than a single instance of very high exposure, the research says.

Children in low-income households, especially African-American children, are more likely to have exposure to lead, the numbers show.

In 2014, low-income children in Michigan who were tested for lead exposure were more than twice as likely to have an elevated level compared to middle-class kids who were tested.

That makes sense since poor families are more likely to live in older homes with lead paint and water pipes, particularly homes that haven't been well-maintained so the paint is flaking and peeling, said Gilda Jacobs, president of the Michigan League for Public Policy, an advocacy group that tracks lead levels in children in its annual Kids Count report.

"If families are renting, they're not going to be the people responsible for replacing the water pipes and the landlord has no incentive," Jacobs saiid.

In addition, exposure to lead is more likely to impact a child who has other stresses in his or her life, such as poor nutrition and health care, experts say.

"Lead exposure is one more insult in a child's life and if a child has had a lot of insults that one more thing can really make a difference in that child reaching his or her full potential," Wells said.

In fact, multiple studies in recent years suggest lead poisoning helps explain the academic achievement gap between black and white children, as well as higher rates of juvenile crime in inner cities. Those studies also show that inner-city children benefit the most from lead remediation programs.

The 2014 University of Michigan study analyzed the current economic implications of childhood lead exposure for individuals and Michigan taxpayers. They include:

$205 million annually in decreased lifetime earnings as a result of individuals whose IQs have been lowered as a result of childhood lead exposure and are less likely to earn a high school diploma or college degree.

$105 million annually in additional costs in the criminal justice system. It's estimated that about 10 percent of Michigan's juvenile crime is a result of childhood lead exposure, which also increases crimes committed by those juveniles as adults.

$18 million spent annually on health care to diagnose and treat lead poisoning plus the medical costs associated with treated cases of attention deficit disorder llnked to elevated lead levels.

$2.5 million annually in additional special education expenditures. The study indicates that 20 percent of children with a blood lead level of 25 mg/dL need an average of nine years of special-education services.

The U-M study compared those annual costs against the $600 million it would cost to remediate 100,000 high-risk housing units in Michigan, saying it is an outlay that would pay for itself after three years.

"This is a problem you can do something about, and our work looked at that cost," said Tracy Swinburn, an economist who co-authored the 2014 report.

While there is little disagreement government is responsible for fixing the lead contamination in Flint, Swinburn said there is a strong case to be made that government should step up spending to clean up lead contamination in general.

"While you could say that paint in a house is personal, private issue, taxpayers would all be better off to pay for remediation of homes than to have to pay the expenses associated with special education and higher crime," she said.

Jacobs agreed.

"It's the whole argument of pay now or pay later," Jacobs said. "There are lifetime consequences for not dealing with this."

Flint in context

To be sure, while lead poisoning affects thousands of Michigan children, Wells said Flint remains unique.

"Flint is not Hamtramck," Wells said, citing a community that has struggled for years with lead toxicity in children as a result of old housing stock and backyards with soil contaminated decades ago by emissions from nearby factories.

"In Flint, the water source changed and lead became part of the water supply, and water is so basic" to daily existence, Wells said.

Moreover, there was an 18-month period in which state and local officials repeatedly assure Flint residents the water was safe to drink, which means many Flint children had prolonged, significant exposure to lead-contaminated water on top of their exposure to lead paint and contaminated soil common in many urban neighborhoods.

Breeze Harden, 3, has her blood drawn while sitting on her mother, Darlene Hart's lap during a free lead testing event and family fun night for children on Tuesday, Jan 26 at Eisenhower Elementary school in Flint. Free water filters were available to families during the event, along with food, refreshments, immunizations, crafts, and a smoothie making bicycle. Conor Ralph | MLive.com

"That makes Flint a very unprecedented situation," Wells said.

Complicating matters is the difficulty in assessing the level of children's exposure to lead at this point.

While health officials are testing the lead levels in as many Flint children as possible, Wells points out that lead stays in the blood for only 30 days. That means a child drinking bottled water since November may well show normal test results.

As a result, Wells said the current round of testing "doesn't tell us anything about the level of exposure" between April 2014 and October 2015, when the lead contamination issues were unaddressed.

And once lead leaves the blood, it doesn't mean the danger has passed. It gets into the bones and teeth and stays forever, with potentially lifelong health implications.

Wells and other health officials are especially concerned about the 9,000 children under age 6 living in Flint. They are considered the most vulnerable because lead is a neurotoxin and so much brain development occurs in the first five years of life.

"We need to consider all 9,000 as exposed and act accordingly," Wells said.

While lead poisoning is irreversible, its impact can be ameliorated by a variety of strategies that are now being put in place in Flint, she said. That includes good nutrition, educational and academic interventions and making sure every child has a primary-care physician who will closely monitor the child's health going forward.

"It's going to take the whole village" to address the issues, Wells said,

But she is convinced Flint is up to the task.

"I've worked in public health for many years, and I've very impressed with Flint," she said. "Flint is strong. Flint can do this. ... The goal is to make Flint a stronger, better community than when this started."

One small silver lining of the Flint water crisis, says Wells and others, is that it has focused national attention on a widespread problem that had gone under the radar.

Wells said she hopes that Flint can become a national model in addressing the issue of lead poisoning. Even now, she said, it has changed the way the state health department is analyzing its lead-testing numbers, to better ensure that spikes of higher lead levels within a county aren't overlooked as they were for a time in Flint.

"Everybody is saying that Flint is the canary in the coal mine, and it really is," Jacobs said.

"The public and public officials are becoming aware of the horrible impact that lead that can have on a child's health and long-term development," Jacobs said. "It's putting a spotlight on changes that need to be made at a local, state and national level."

Julie Mack is a reporter for MLive.com. Email her at jmack1@mlive.com, call her at 269-350-0277 or follow her on Twitter @kzjuliemack.

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