Children with ADHD often show signs like being very active, acting without thinking, or having trouble paying attention. In Catalonia, Spain, about 6% of school-aged children are thought to have this condition.
While genetics is the main cause, scientists now believe that things in the environment, like pollution, can also play a role in making ADHD worse or even triggering it.
A group of researchers from the Universitat Rovira i Virgili (URV) looked into how exposure to heavy metals might affect brain development and behavior in children. These metals can build up in parts of the brain that are linked to attention and self-control, such as the hippocampus and the frontal cortex.
Their study included 205 children between 6 and 16 years old. Among them, 139 had been diagnosed with ADHD, and 66 children did not have any known developmental disorders. All of the children were carefully assessed by researchers using standard international guidelines.
In addition to checking for ADHD, the researchers also tested each child’s thinking abilities—like memory, verbal understanding, and how quickly they could process information. They collected urine samples from the children to test for levels of different metals, including copper, lead, cadmium, mercury, arsenic, and antimony.
The results showed a strong link between higher metal levels and the likelihood of having ADHD. Children with the highest levels of lead were five times more likely to have ADHD.
For copper, the risk was even higher—those with the most copper were sixteen times more likely to be diagnosed with the condition. Smaller connections were also seen with cadmium and antimony.
Although copper is needed for the body to grow and stay healthy, too much of it can be harmful. The researchers found that high copper levels were not only linked to ADHD but also to more severe symptoms, such as inattention and impulsive behavior.
Lead, which is dangerous even in tiny amounts, was also linked to slower thinking and reaction times. These effects were more noticeable in children who already had ADHD.
Mercury was another metal that stood out. Even at similar exposure levels, children with ADHD were more affected by mercury than those without the condition. They showed more inattention, skipped more questions during testing, and had less consistent reaction times.
The scientists said that while their study doesn’t prove that heavy metals cause ADHD, it adds strong evidence that reducing contact with these pollutants can support better brain development. This could help all children, especially those who are already at risk.
The team is continuing their research and is now looking into how air pollution might affect children’s mental health. They are calling for stronger public health efforts to limit exposure to harmful metals in the environment.
These metals can be found in soil, water, air, and even food. Better rules on industrial emissions, waste management, and food safety could help protect children and improve their learning and behavior.
If you care about autism, please read studies about a new cause of autism, and cats may help decrease anxiety for kids with autism.
For more information about health, please see recent studies about vitamin D that may hold the clue to more autism, and results showing strange eating habits may signal autism.
The study is published in the Journal of Attention Disorders.
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