Lead: Not just an issue in Flint

The Flint, Michigan water crisis—during which the Environmental Protection Agency (EPA) says blood lead levels in children rose by 46%—was an eye opener for public health. Now, a new study by Quest Diagnostics in Madison, New Jersey, published in the Journal of Pediatrics reveals that 3% of young children nationwide have blood lead levels exceeding the 5 µg/dL threshold set by the Centers for Disease Control and Prevention (CDC).

The 6-year study examined blood tests from 3.8 million children aged younger than 6 years, with varying levels across the nation. Over the course of the study, the number of children with high blood lead levels declined from 3.67% to 2.59%, but there is no number that is acceptable, according to the American Academy of Pediatrics (AAP).

Recommended: What's new about lead poisoning

“This study . . . shows us that we may have had some successes, yes they were less elevated over the time period they looked at, but lead is still a problem,” Jennifer A Lowry, MD, FAACT, FAAP, chair of the AAP Council on Environmental Health Executive Committee, said in an AAP statement on the report.

That problem was evident over the last several years as a water crisis—affecting nearly 100,000 people—unfolded in Flint.

The problem in Flint began in 2014 when the state switched Flint’s water source from Lake Huron water, supplied by the Detroit Water Authority, to Flint River water supplied by the Flint Water System as a cost-saving measure.

Lead toxicity can come from a variety of sources, and typically occurs after exposure to lead-based paint or lead-contaminated dust. However in Flint, the water supplied by Flint Water System wasn’t treated with corrosion control, which prevents corrosion of leaded plumbing that can then infiltrate tap water.

Although residents had complained for some time after the switch about the water appearing dirty and smelly, it wasn’t until Marc Edwards, a civil engineer from Virginia Tech in Blacksburg, began finding dangerous amounts of lead in water from Flint homes that the truth was exposed. Edwards’ findings inspired Mona Hanna-Attisha, MD, MPH, director of the pediatric residency program at Hurley Medical Center in Flint and pediatrics professor at Michigan State University in East Lansing, to begin combing hospital records for cases of elevated blood lead levels—eventually finding cases had tripled in some areas of the city since the water supply switch.

The 2 investigators were later recognized by TIME magazine for their role in uncovering the public health scandal in Flint, which led to a state of emergency, widespread political fallout, and policy changes.

NEXT: New report from the CDC

A new report released by the CDC on June 24, 2016, details the magnitude of the water crisis in Flint, with the agency revealing that blood lead levels in children aged younger than 6 years residing in areas supplied by Flint Water System rose roughly 46%—from 3.1% when water was supplied by the Detroit Water Authority to 5% after the switch to Flint Water System.

By January 2015, a water advisory was issued, and by October, Flint switched back to the Detroit Water Authority for its water supply. Residents today are still encouraged to drink filtered or bottled water, and the scandal resulted in raised awareness about lead contamination.

The EPA is updating its Safe Drinking Water Act, with changes expected by 2017, and the US Department of Housing and Urban Development (HUD) recently made available a toolkit and guidance to address lead hazards in public housing. The HUD’s new initiative seeks to increase monitoring and mitigation of lead hazards, and increase funding through $46.5 million in lead reduction grants that could impact more than 3000 low-income homes.

More: Follow-up on childhood lead exposure falls short

An updated policy statement from the AAP was also just released, and calls for stricter regulations and increased surveillance to prevent high blood lead levels in children. The AAP, echoing the CDC, stresses that there is no safe level of lead, and that even children with blood lead level concentrations below 5 µg/dL may experience cognitive deficits, leading to poor academic performance. In children with higher blood lead level concentrations, the neurotoxic effects can be devastating.

Harvey W Kaufman, senior medical director, Quest Diagnostics and a study author, says the information in the company’s report can be particularly helpful to pediatricians to ramp up surveillance measures. The report offers a breakdown of blood lead levels, and pediatricians can identify regions that are high risk in their practice area.

“A lot of pediatricians just don’t have access to that information,” he says.

NEXT: Where are the highest blood lead levels?

According to the Quest Diagnostics report, high blood lead levels were most prevalent in Minnesota (10.3%), Pennsylvania (7.8%), Kentucky (7.1%), Ohio (7%), and Connecticut (6.7%). Typically high blood lead levels are found in areas with high poverty rates and older homes built before 1950.

Regionally, children in several areas in New York, Pennsylvania, and Ohio had particularly high blood lead levels, with more than 14% of children having high blood lead levels in those areas. In New York, those areas included Syracuse, Buffalo, and Poughkeepsie; in Pennsylvania, it was York and Oil City; and in Ohio, extremely high blood lead levels were found in Cincinnati. Additional areas where blood lead levels tests reached 10 µg/dL or higher included Niagara Falls, New York; Reading and Erie, Pennsylvania; and Cleveland, Ohio.

Next: Top mosquito repellent recommendations for Zika virus prevention

The lowest blood lead levels were found in Florida (1.1%) and California (1.4%), according to the Quest report.

Additionally, while national blood lead levels decreased over the course of Quest’s study, Mississippi saw a sharp rise, from 3.1% to 6.3%, compared with a decline in New Hampshire from 9.7% in the first year of the study to 2.6% by the final year.

Although lead toxicity rates have greatly improved over the decades, it’s also become easy to forget about the importance of screening, Kaufman says.

“There are some pediatricians who remember 10, 20, 30, 40 years ago and think we’ve largely addressed the issue, but this paper clearly states we clearly have some more progress to go,” Kaufman says. “There’s a certain amount of complacency that builds in over time because we’ve made that great progress. We’d love to have pediatricians use this information to target geographies that are more problematic.”

Kaufman says although the study shows a decrease in overall national blood lead levels, the Healthy People 2020 goal is to reduce the number of children with blood lead levels above 10 µg/dL to zero.

“It would be a beautiful thing for all of us if we actually achieved that,” Kaufman says. “The reality is that we’re at least going to progress in that direction, and it will be a combination of parents, pediatricians, and policy makers acting together to address this issue.”

In its updated statement on the prevention of lead toxicity, the AAP calls for increased federal, state, and local surveillance efforts, and improved protocols from the EPA and HUD for mitigating residential lead. Pediatricians should screen children who live in homes built before 1960, particularly those that have undergone recent renovation, says the AAP. Screening questionnaires, blood lead level testing, and environmental assessments are all good tools for pediatricians to use, but the AAP also urges pediatricians to advocate for government inspections and enforcement of public health standards.