💀 You have no idea how contaminated our parents were with lead

A research team obtained an unexpected result by studying preserved hair, with the oldest samples dating back to 1916. These locks of hair offered the possibility of reconstructing the lead exposure of the inhabitants of the United States.

Scientists from the University of Utah examined hair samples belonging to 48 people, collected up to the present day. Several participants even provided locks of hair from parents or grandparents, carefully kept in family albums. This original approach was made possible thanks to a local tradition of preserving genealogical archives.


The analyses reveal a notable decrease in the quantities of lead measured in the hair. Before the 1970s, concentrations could climb as high as 100 parts per million. Nowadays, they are below the threshold of one part per million. This drop closely follows the gradual elimination of lead in gasoline, paint, and water pipes.

Throughout the 20th century, this heavy metal was ubiquitous in everyday life. Added to gasoline to increase engine power, it was also a component in paints and pipes. Its danger, particularly harmful to children's brain development, was not fully identified until decades later, leading to the introduction of strict legislation.

The analysis technique used is based on mass spectrometry, capable of detecting tiny amounts of lead fixed to the surface of the hair. Unlike blood, which reflects immediate exposure, hair records a trace of contact over long periods.

The Utah area, once characterized by intense industrial activity, saw its pollution levels drop drastically after the closure of smelters and the implementation of new regulations. The region's inhabitants directly benefited from this.

How lead affects human health

This heavy metal accumulates gradually in the body. After inhalation or ingestion, it lodges in bones and tissues, where it can remain for many years. This slow poisoning is often imperceptible initially, but its long-term consequences are well established.

For children, even small amounts can hinder brain development. Lead disrupts the transmission of nerve signals, which can cause learning disabilities, reduced intellectual abilities, and behavioral changes. Young individuals are more sensitive because their nervous system is still developing.

In adults, prolonged exposure to lead increases the probability of developing cardiovascular and kidney diseases. It can also harm fertility and worsen other health conditions. Workers in industries that use this metal are particularly affected, requiring adequate protective equipment.

Prevention is organized around reducing sources of exposure. Removing lead from consumer goods, such as gasoline or paints, has significantly reduced poisoning cases.