A new study says that unsafe recycling of batteries exposes children to lead poisoning.

Lead is a potent neurotoxin that is particularly detrimental to children’s cognitive development, according to experts; and batteries account for at least 80 percent of global lead use.

Unsafe battery recycling is a major contributor to childhood lead poisoning, scientists warn.

The new study says that reversing the damage done to the soil through indiscriminate battery recycling will save children living in affected environments  from lead poisoning and associated dangers.

The study, published in Science Direct, notes that residents of areas where vehicle batteries are disposed off indiscriminately risk exposure to lead poison since they most likely rely on the contaminated site for their livelihoods and for recreation.

Unsafe recycling of batteries is common in Nigeria, as reported by the Heinrich Böll Stiftung, a German political foundation.

A 2018 report published by the Heinrich Böll Stiftung states that Nigeria, at the moment, does not yet have a high adoption of renewable energy, and most of its residents still rely on diesel- and petrol-powered generators to compliment the unstable energy they get from the national grid.

“But there is a growing demand for stand alone solar solutions as the prices of solar panels continue to fall globally,” it says; adding, “As welcome as this development is, more toxic lead acid batteries — a major component to stand alone solar solutions — will end up at dumpsites across the nation after their use.”

Stanford University scientists, along with the International Centre for Diarrhoeal Disease Research, Bangladesh, and other institutes conducted the research.

The study was conducted in Bangladesh and it found that at baseline, distance to contaminated sites correlated with blood lead level.

It warns that soil lead concentrations were high in environments where batteries were recycled, and that lead levels were high in the blood of children living in such environments.

In the introduction to the study, the researchers note that lead is a potent neurotoxin that damages nearly every system in the body, experts say; noting that effects of early childhood lead exposure can vary from impaired neurodevelopment to encephalopathy and death.

Although there is no safe level of lead exposure, the U.S. Centres for Disease Control has set 5 μg/dL as a threshold that triggers government intervention and case management for a child.

According to researchers, lead exposure is particularly detrimental before birth through age three, when children’s brains are rapidly developing.

During this time, any level of lead exposure can irreversibly damage the brain, permanently lower IQ, and reduce lifetime earnings.

It is estimated that up to 100 million people around the world are exposed to lead contamination in soil, which disproportionately affects children in low- and middle-income countries.

The scientists say simple soil remediation can substantially reduce levels of the toxic metal lead in the blood of children living in heavily contaminated areas.

Experts say lead exposure can affect every system of the human body.

In children, it can affect brain development, resulting in reduced intelligence.

Every year, intelligence deficit and reduced productivity from lead exposure costs the world about $1 trillion and Bangladesh $16bn, according to the study.

The study showed that removing contaminated soil and fallen leaves led to a 96 per cent reduction in soil concentrations of lead and a 35 per cent lowering of lead in the blood of children living in an area where lead batteries were recycled.

A press release by Stanford University said potent neurotoxin still lurks in one in every three children globally.

An earlier assessment in Bangladesh found nearly 300 recycling sites with elevated soil lead concentrations, with some 700,000 people across the country living within contaminated sites, the release said.

Soil remediation involved scraping off between one and two centimetres of soil and leaf matter in areas close to smelting zones and four to five centimetres within smelting zones. To ensure that sufficient soil was removed, lead concentrations in underlying soil were measured, the study says.

Study co-author and professor at the Stanford Woods Institute for the Environment, Stephen Luby, says that all 69 children who participated in the study had dangerously high blood lead levels.

“With focused efforts to decontaminate the area the intervention substantially reduced their blood lead levels,” Luby told SciDev.

Corresponding author of the study and post-doctoral fellow at Stanford University, Jenna Forsyth, says soil remediation is a critical tool to reduce lead exposure.

“Without remediation, contaminated soil would be a source of lead exposure for generations since the estimated half-life of lead in soil is estimated at around 700 years,” Forsyth said.