Last year I spent a considerable amount of time collaborating to create the first clinical textbook of environmental medicine with two icons in this field, Dr. Walter Crinnion and Dr. Joseph Pizzorno. This tremendous work was recently published and is now available in many outlets, including on Amazon. My contributions include chapters on the physiologic processes that accomplish the excretion of toxins for different body systems. The section that I wrote on hair excretion includes a novel interpretation of the literature on heavy metal (hair) analysis in Autism Spectrum Disorder, detailing how there are particular "windows" of increased sensitivity to the molecular environment of the brain. These windows coincide with changes in the developmental organization of the brain, with the most important factor being an adequate supply of zinc. Zinc is crucial for proper excitatory balance, and when there is inadequate zinc, the body will up-regulate many processes that can result in increased toxic metal uptake if the zinc continues to be unavailable. The book is highly referenced and contains a wealth of information!