Some earlier studies have shown that exposure to lead affects the IQ of children but not much was known about the effect of lead exposure on the behavioral and emotional health of kids.
A new study has now shown that emotional and behavioral problems occur in kids even when they are exposed to low levels of lead while in preschools. This problem continues to increase with rising blood lead levels.
The findings of the study are published in the journal JAMA Pediatrics. Dr. Jianghong Liu of the School of Nursing at the University of Pennsylvania, Philadelphia, and colleagues conducted the study. They analyzed links between blood lead levels in over 1,300 Chinese preschoolers and behavioral and emotional problems, including anxiety, depression or aggression.
Dr. Liu wrote: "Young children are particularly vulnerable to the toxic effects of lead, because lead can affect children's developing nerves and brains."
Lead is present naturally in the environment and humans get exposed to this metal due to mining, burning fossil fuels, and manufacturing. In the US, the paint, caulking and pipe solder are most common sources of lead exposure. In China, people are exposed to lead due to air pollution.
The study showed that in China, blood lead concentrations increased with age in preschool children. In the US, the scene is little different as the lead goes up until around age 2 or 3, and then its level start to decrease. The researchers said that these differences are due to different sources of lead exposure in the two countries.
The study focuses on lower blood levels than most other studies, explains Dr. Kimberly Gray, Health Scientist Administrator at the National Institute of Environmental Health Sciences (NIEHS), which funded the study. Dr. Gray says the study "adds more evidence that there is no safe lead level," and that it is "important to continue to study lead exposure in children around the world, and to fully understand short-term and long-term behavioral changes across developmental milestones."