Trainee Megumi Matsushita synthesized the state of knowledge about cadmium's neurotoxic effects for members of CHE-WA.
On April 9th, Megumi Matsushita, a trainee on UW SRP Project Two advised by Dr. Zhengui Xia, was the featured speaker for the monthly meeting of Washington's chapter of the Collaborative on Health and the Environment (CHE-WA). In her online presentation, Matsushita summarized epidemiological and toxicological evidence linking cadmium exposure with cognitive impairment in children and adults.
Evidence is mounting that cadmium has powerful neurological effects even at low doses. However, health standards have been set using kidney damage as the most sensitive biological endpoint. Newer science, including evidence from the Xia lab, suggests that regulations should become more protective in light of adverse neurological outcomes associated with levels of cadmium routinely found in the bodies of average Americans.
Matsushita presented epidemiological results from children's health data linking higher levels of urinary cadmium to increased rates of learning disabilities and special education. She also summarized results from her own lab.
Learning and memory formation depend on the production of new neurons in the part of the brain known as the hippocampus. Work by Dr. Hao Wang, another trainee in the lab of Dr. Xia, shows that cadmium exposure impairs hippocampus-dependent learning and memory in mice. Not only are these results seen in behavioral tests, but cadmium exposure has been shown to directly impair new neurons in the hippocampus from forming and maturing, and actually causes the death of the stem cells that produce them. These results are seen after experimentally exposing mice to low levels of cadmium in drinking water that result in blood levels similar to those seen in the U.S. population.
Masushita concluded by opening a discussion of suggested actions to help protect human health. These were to update the ATSDR cadmium toxicological profile and to try to minimize exposures by influencing consumer behaviors.