Lead is an invisible pollutant. But one that is toxic to human health, and has large impacts on cognitive function, learning and decision-making. It’s particularly harmful when children are exposed at a young age – these impacts can be irreversible.
Thankfully many countries have made great progress against lead pollution. In the chart we see the decline in lead concentrations in the blood of children in the United States. This dates from the late 1970s onwards.
In 1978, the average concentration in children aged one-to-five years old was 15 µg/dL. Today the US CDC sets a target threshold for every child to have concentrations lower than 3.5 µg/dL. So, average concentrations were more than four times above acceptable levels. And some children had exposure levels up to 30 µg/dL – more than eight times too high.
This means most children in the US in the 1970s were suffering from lead poisoning.
But since then we have seen an impressive decline. By far the biggest impact was the phase-out of leaded gasoline through the 1970s and 1980s. This was the largest source of lead. By 1990, average levels were below 5 µg/dL (although some children were still exposed to levels well above 10 µg/dL).
This decline continued by tackling other common sources of lead; the primary focus of efforts since then has been on eliminating lead from paints used in households. By 2016, the median level was just 0.7 µg/dL – a 95% decrease from 1978.
This progress has been mirrored across the world. By 2021, every country in the world had phased out leaded gasoline in road vehicles. This means many will have seen the impressive drop in lead pollution that we see for the US.1
Yet, in many low-to-middle income countries, other sources of this toxin remain. To make sure this progress continues we need to eliminate lead in products such as paints, pipes, and improve the management of electronic waste.