In the late 1990s and 2000, I conducted—along with my colleagues at the University of Pennsylvania Department of Radiology and Psychiatry—a study to really address the issue of how lead affects the brain itself. Many of the studies that existed before were epidemiological studies, or neurobehavioral studies and behavioral studies using IQ tests and psychological evaluations. These are very important and really attest to the functional organization of the brain, but the issue of confounders was debated very fiercely at that time and it was very difficult to parcel out these confounding variables when we were talking about these epidemiological studies.
So, we had an idea that we should actually look at the brain itself. We wanted to know, does lead have an actual effect on the brain? We wanted to see how lead affects brain metabolites, so we set out to study children who had lead levels above 10. For the control group—to see the differences between the brains of children exposed to lead and those not exposed to lead—we used children who were either cousins or relatives of the children that were exposed. Our study was relatively free of confounding variables because the lead-exposed kids and the control group came from the same socio-economic environment. We also used another method called MRS—Magnetic Resonance Spectography—which allowed us to analyze different chemicals in the brain and their relevance to different neuronal liabilities.
The main conclusion from our studies was, yes, the lead affects the brain itself it and it affects the metabolites of the brain. The second conclusion was that, in our study, not many confounders could account for the results. So, it’s easier to establish a causal association with the actual lead exposure.
A number of studies followed our study, which backed up our conclusion that lead levels above 10 have a detrimental effect on the central nervous system, independent of confounding variables. I think we can be pretty confident of that conclusion—there’s a lot of information that tells us this conclusion is pretty good, pretty savvy.
Dr. Idit Trope is a clinical and forensic neuropsychologist from Philadelphia, PA. She received her Ph.D. from the University of Pennsylvania, where she also conducted her research on lead poisoning, and published in peer review journals. Dr. Trope has been engaged in clinical neuropsychology since 1993. In her clinical practice, which consists of neuropsychological evaluations and teaching, Dr. Trope sees children, adolescents and adults with known or suspected brain dysfunction, including developmental disabilities, concussions/head injuries, epilepsy, stroke, ADHD and psychiatric conditions on referral from schools, primary care physicians, neurologists, neurosurgeons, psychologists and psychiatrists. She also consults on cases in which there are allegations of concussion, traumatic brain injury, brain dysfunction, psychiatric disorders or emotional distress secondary to medical malpractice, toxic exposure, personal injury and PTSD. Dr. Trope was a featured speaker at HB’s Lead Litigation Conference in October 2011.