Lead exposure linked to mental decline

Reported by Susan Aldridge, PhD, medical journalist

Years of exposure to lead in the environment can lead to mental decline as people age, according to a new study.
Lead is known to be toxic because of its effects on the brain. Fortunately levels have been going down in recent years because of environmental legislation. Now a team at Harvard Medical School look at how exposure in past years is affecting people's health now.

They used x-rays to find out levels of lead in bone and, at the same time, carried out mental tests on participants at two time points 3.5 years apart. The higher the levels of lead in the kneecap, the greater the decline in mental functioning. The effects were subtle but show that there is no room for complacency or relaxation of standards when it comes to lead exposure. The team is continuing to follow the group to see if the adverse effects of lead taper off or get worse with age.

Source
American Journal of Epidemiology December 2004

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