Role of perfumes in pathogenesis of autism

Abstract

Autism spectrum disorders (ASDs) are developmental conditions characterized by deficits in social interaction, verbal and nonverbal communication, and obsessive/stereotyped patterns of behavior. Although there is no reliable neurophysiological marker associated with ASDs, dysfunction of the parieto-frontal mirror neuron system and underdeveloped olfactory bulb (OB) has been associated with the disorder. It has been reported that the number of children who have ASD has increased considerably since the early 1990 s. In developed countries, it is now reported that 1-1.5% of children have ASD, and in the US it is estimated that one in 88 children suffer from ASD. Currently, there is no known cause for ASD. During the last three decades, the most commonly accepted paradigm about autism is that it is a genetically inherited disease. The recent trio analyses, in which both biological parents and the autistic child's exomes are sequenced, do not support this paradigm. On the other hand, the environmental factors that may induce genetic mutations in vitro have not been clearly identified, and there is little irrefutable evidence that pesticides, water born chemicals, or food preservatives play critical roles in inducing the genetic mutations associated with known intellectual deficiencies that have been linked to autism spectrum disorder (ASD). Here, we hypothesize and provide scientific evidence that ASD is the result of exposure to perfumes and cosmetics. The highly mutagenic, neurotoxic, and neuromodulatory chemicals found in perfumes are often overlooked and ignored as a result of a giant loophole in the Federal Fair Packaging and Labeling Act of 1973, which explicitly exempts fragrance producers from having to disclose perfume ingredients on product labels. We hypothesize that perfumes and cosmetics may be important factors in the pathogenesis of ASD. Synthetic perfumes have gained global utility not only as perfumes but also as essential chemicals in detergents, cosmetics, soap, and a wide variety of commonly used items, even in food flavoring to enhance product taste. Here we provide evidence that a majority of perfumes are highly mutagenic at femtomolar concentrations, and cause significant neuromodulations in human neuroblastoma cells at extremely low levels of concentration, levels that are expected to reach a developing fetal brain if the pregnant mothers are exposed to these chemicals.