A quarterly publication of the Autism Research Institute

The Autism Research Review International is quarterly publication of the Autism Research Institute

Winter, 2021 | Number 1, Volume 35

Diesel pollution linked to autism symptoms in study of rats

A new study adds to evidence implicating air pollutants as a factor in autism spectrum disorders (ASD). 

In the study, Tin-Tin Win-Shwe and colleagues examined the effects of exposure to a substance called diesel exhaust origin secondary organic aerosol, or DE-SOA. This is a pollutant created by chemical reactions between diesel exhaust particles and gases in the atmosphere. 

The researchers exposed pregnant rats to clean air or air contaminated with diesel particulates or DE-SOA from gestational day 14 to postnatal day 21. They investigated the behavior of the rats when they were between 10 and 13 weeks old, and later examined the prefrontal cortices of the animals. 

The researchers report, “Developmental exposure to DE-SOA induced autism-like behaviors such as poor social interaction, social dominance, and repetitive behavior in male and female rats. These poor social behaviors [were] accompanied by changes of molecular markers such as neurological and immunological biomarkers in the prefrontal cortex.” 

They comment, “It is possible that the toxic substances from DE-SOA may translocate to the fetal brain via the olfactory nerve route or systemic circulation and induce neuroinflammation. Neuroimmune interaction, synaptic dysfunction, immune dysregulation, and excitatory-inhibitory imbalance are major contributing factors for the development of ASD in response to environmental pollutant exposure.” 

The researchers note that their findings are consistent with a number of human studies showing associations between exposure to air pollutants during brain development and ASD. 


“Perinatal exposure to diesel exhaust-origin secondary organic aerosol induces autism-like behavior in rats,” Tin-Tin Win-Shwe, Chaw KyiTha-Thu, Yuji Fujitani, Shinji Tsukahara, and Seishiro Hirano, International Journal of Molecular Sciences, January 2021 (free online). Address: Tin-Tin Win-Shwe, Center for Health and Environmental Risk Research, National Institute for Environmental Studies, Tsukuba 305-8506, Japan, [email protected].