Lead poisoning is one of the causes of sleep problems in small children, a major new study has found.
Over-exposure to lead in early childhood can cause sleep problems from insomnia to daytime sleepiness in later childhood.
Lead pollution can come from car exhausts, and industrial and manufacturing processes, and it is a problem for all industrialised and developing countries.
Researchers from the University of Pennsylvania have found that sleeping problems were up to three times greater in children with the highest levels of lead in their blood. They made the discovery after they analysed the sleeping habits of around 1,400 children in China, where air pollution is especially bad.
Those who reported sleeping problems such as insomnia and using sleeping pills had the highest levels of lead in their blood, which was measured when they were aged between three and five years, and again six years later.
Although it`s already recognised that lead can cause neurological problems, the researchers say that sleep problems are another, and unrecognised, symptom of lead poisoning.
(Source: University of Pennsylvania School of Nursing, November 12, 2015)