Picturing the brain on lead.

Nov 18, 2008

Jiang Y, L Long, X Zhu, H Zheng, X Fu, S Ou, D Wei, H Zhou and W Zheng. 2008. Evidence for altered hippocampal volume and brain metabolites in workers occupationally exposed to lead: a study by magnetic resonance spectroscopy. Toxicology Letters 181:118-125.


A part of the brain that controls short-term memory and learning is smaller in workers who were exposed to lead while at work and had high levels in their blood. People who work with the heavy metal may develop subtle brain changes that could increase their risk of neurological disorders.

Research in China indicates that long-term, occupational exposure to the  lead may cause changes in brain structure and function in humans.

Lead exposure has been linked to adverse neurological effects in people, particularly on cognitive function. Lead tends to accumulate in certain areas of the brain, such as the hippocampus, the center of the brain critical for short term memory. In this study, lead-exposed workers had significantly reduced volume of the hippocampus, about 6% lower compared to non-exposed workers. These individuals also had elevated levels of N-acetyl-asparate (NAA) indicating the loss of neuron integrity.

To collect the data, researchers compared the brain sizes of 15 lead-exposed employees at smelting or battery manufacturing plants to 19 non-exposed workers in other lines of work. Exposed workers had an average of 64 micrograms/dL blood lead concentration compared to 8.7 for non-exposed workers. They also used similar tools to measure the levels of key molecules in the brain that are associated with neurological disorders, such as Alzheimer's disease and brain cancer.