The center for Disease Control and Prevention (CDC) has found that 1 in 110 children in the US have been diagnosed with Autism Spectrum Disorder (ASD), up from 1 in 150 in 2007. A study in the "Journal of Pediatrics" in October 2009 revealed similar numbers. Parents of 1 in 90 children reported that their child has ASD. That report is now 1 in 58. Autism is the fastest growing developmental disability affecting more children than cancer, diabetes, and AIDs combined. Another disease reaching epidemic proportions is thyroid disease. According to a study published in the journal "Cancer," July 13, 2009, thyroid cancer doubled in the last 10 years. Some researchers feel that the significant increase in thyroid cancer is related to the significant increase in auto immune thyroid disease that goes untreated. Subclinical hypothyroidism associated with an elevated TSH can stimulate the thyroid gland, leading to the increased risk of cancer. Additionally, according to researchers, if the upper portion of the normal range of TSH (the routine thyroid blood test) was lowered to 3 as The American Association of Clinical Endocrinologist (AACE) recommends, approximately 20% of the population would be hypothyroid. One doesn't have to look very deeply to appreciate that these two disorders are interconnected. Firstly, both are associated with the increasing burden of environmental toxicity. Both the brain and the thyroid are very susceptible to toxins. Additionally, neurotoxins such as PCBs and Dioxin, likely to be associated with neurological disorders such as autism, exert some of their effects on the brain through their effects on the thyroid. Hypothyroidism can have a profoundly deleterious effect on the developing brain, thus significantly contributing to the web of causes of autism. Other toxins which can contribute to both autism and hypothyroidism include lead and mercury. In this article, the author examines the link between thyroid disease and autism.