Now I get it! Thanks for the clarification.

Lead, cadmium, and manganese are neurotoxic metals to which you can add mercury. Lead exposure in childhood is particularly devastating as it can result in permanent cognitive and behavioral deficits. Elevated manganese levels can cause Parkinson's-like symptoms. Cadmium primarily impacts the kidneys and male reproductive system. Their neurotoxic effects play out primarily in the central nervous system, not so much in the muscle cells per se. It's the brain neurotransmitter metabolism that is affected by exposure to these elements. They are are also sex-specific neurotoxic effects potentially due to hormonal, genetic, and epigenetic factors.