There is a reason why the WHO has called the use of red petrol, that is, that is enriched with lead, “a health catastrophe”, one of the worst mistakes of the 20th century. The consequences of the use of this added fuel on global health are still being felt today, 50 years after the first disposal measures in the USA and 20 after the definitive end of its production in Europe. Based on a new study published in Science Advancesthose who were exposed to lead as a child, because it is present in gasoline, paints or plumbing pipes, may have reduced cognitive abilities in old age, that is, show the symptoms of dementia earlier than their peers.
Pervasive damage. Although lead exposure has long been associated with impaired cognitive performance and aggressive behaviors especially in children, whose brains are more susceptible to lead poisoning, the study is the first to investigate its long-term effects and in ‘old age.
As John Robert Warren, a sociologist at the University of Minnesota in Minneapolis, one of the authors of the research explains, “in the USA, and I imagine in the UK, the first years in which children were exposed to the greatest quantities of lead were the 1960s. it’s 70s. This was the time when more leaded gasoline was used, when lead paints were still common and municipal water systems still hadn’t done much to remove lead from plumbing. ‘
The social problem. Now these people are adults in their 50s or 60s. If lead really facilitates the onset of the typical symptoms of dementia, it could mean that in the next 10 or 20 years this form of pathological aging will become even more common. Warren compared the data from the US study Health and Retirement Study (HRS), which has tracked the cognitive health of thousands of Americans over the past few decades, with insights into places where 1,089 of these people had lived childhood. The scientist and colleagues also traced maps of towns and cities that used lead plumbing at the time and had acidic or alkaline water – characteristics most associated with lead contamination.
Disadvantaged start. Those who had lived in cities with contaminated water as a child showed worse basic cognitive functioning (a measure of the ability to learn, process information, reason even in the absence of disease) at the age of 72 compared to those who had not been exposed to lead.
The difference between the two groups was equivalent to about eight years of brain aging. Although this does not translate automatically in an increased risk of dementia, however, it means “starting from a substantially lower point, and then potentially starting to have more problematic levels of cognitive decline before the others,” explains Warren.
It’s not over yet. It is often tempting to think of lead pollution as a solved problem, also thanks to one of the most effective environmental mobilizations ever. Studies like this show instead that the toxic legacy of this metal will accompany us for decades and that solutions are needed to mitigate the consequences. Especially for the poorest countries, which were the last to abandon the use of lead in petrol and which could also pay the highest social cost this time.