OBJECTIVE: Environmental pollutants, especially environmental toxins (ET), may have the potential to disrupt neurodevelopmental pathways during early brain development. This study was designed to test our hypothesis that mothers with autism spectrum disorder (ASD) children would have less knowledge about ET and more chance to be exposed to ET than mothers with healthy children (MHC). METHODS: One hundred and six biologic mothers with ASD children (MASD) and three hundred twenty four biologic mothers with healthy children MHC were assessed using two questionnaires asking about ET. RESULTS: The total score in response to questions related to knowledge about ET in MHC was higher than that in MASD. The possibility of exposure to ET was higher in MASD than MHC. MASD showed higher sub-scale scores in terms of exposures to canned food, plastics, waste incinerators, old electronics, microwavable food, and textiles. CONCLUSION: The current results show that reduced knowledge about ET and greater exposure to ET may be associated with autism spectrum disorder.
Autistic Disorder ; Brain ; Child ; Autism Spectrum Disorder ; Electronics ; Electrons ; Environmental Pollutants ; Food, Preserved ; Humans ; Mothers ; Plastics ; Surveys and Questionnaires ; Textiles

OBJECTIVE: Methamphetamine (MA) use rates in the United States (US) have consistently demonstrated geographical variation and have been higher in the West and Midwest. This uneven pattern of use could be explained by regional differences in MA manufacturing and distribution, but may also result from differences in altitude. The hypobaric hypoxia found at high altitude alters neurotransmitter synthesis in the brain, which may contribute to MA use. The present study investigated the relationship between mean altitude and MA use rate in the 48 contiguous US states and the District of Columbia. METHODS: State-level estimates of past year MA use were extracted from the National Survey on Drug Use and Health report. The mean altitude of each state was calculated using the Shuttle Radar Topography Mission altitude data set. RESULTS: There was a significant positive correlation between mean state altitude and MA use rate (r=0.66, p<0.0001). Multivariate linear regression analysis showed that altitude remained a significant predictor for MA use rate (beta=0.36, p=0.02), after adjusting for age, ethnicity, education, socioeconomic level, employment, MA laboratory incidents, subpopulations, and other substance use. CONCLUSION: Altitude appears to a possible contributing factor for regional variation of MA use in the US. Further studies will be required to determine biological changes in neurotransmission resulting from chronic mild hypoxia at high altitude in MA users.
Altitude* ; Anoxia ; Brain ; Dataset ; Education ; Employment ; Humans ; Linear Models ; Methamphetamine* ; Missions and Missionaries ; Neurotransmitter Agents ; Synaptic Transmission ; United States*