I have a child who is delayed and cant speak, at age 5 they diagnosed my daughter with moderate autism. What I have found through research is that a study was conducted on a group of young children who all have high levels of lead in their systems. The results of the experiment determined that at a certain age (4, 5 years old) the children were either diagnosed with ADHD or Autism. It was their conclusion that when children experience high levels of lead in their systems the lead can mimic ADHD or Autism. By the time these children entered high school the lead was out of their system and there were no more symptoms and they proceeded to live normal lives.