Emotional and behavioural problems show up even with low exposure to lead, and as blood lead levels increase in children, so do the problems, according to research funded by the National Institute of Environmental Health Sciences (NIEHS) in the US, part of the National Institutes of Health. The results were published online in the journal JAMA Pediatrics.
“This research focused on lower blood lead levels than most other studies and adds more evidence that there is no safe lead level,” explained NIEHS Health Scientist Administrator Kimberly Gray, PhD. “It is important to continue to study lead exposure in children around the world, and to fully understand short-term and long-term behavioural changes across developmental milestones. It is well-documented that lead exposure lowers the IQ of children.”
Blood lead concentrations measured in more than 1 300 pre-school children in China were associated with increased risk of behavioural and emotional problems, such as being anxious, depressed or aggressive. The average blood lead level in the children was 6,4 micrograms per decilitre.
Lead is a naturally occurring toxic metal, but sources of lead exposure are often due to human activities, including burning fossil fuels, mining and manufacturing. In the US, lead exposure usually comes from lead-containing products such as paint, caulking and pipe solder in older homes. In China, lead exposure is more often related to air pollution.