Air pollution has always been an environmental concern, and the presence of large amounts of carbon in the atmosphere led to the thinning of our ozone layer which has resulted in our present-time problem--climate change. Similarly, toxic chemicals released in factories and inhaled from cigarette smoke have been a known cause of mental and physiological retardation particularly amongst the exposed unborn babies. However, new research has discovered yet another adverse effect from the air we breathe. Air pollution is now being linked to Autism Spectrum Disorders (ASD).

According to a preliminary study conducted by a research team from the University of Pittsburgh Graduate School of Public Health, children who have been exposed to certain air pollutants during conception or during the developmental stage in their mothers' womb were more at risk for developing autism and related conditions.

The results of the study were presented at the American Association for Aerosol Research in Orlando, Florida yesterday, and they revealed a correlation between environment, particularly exposure to air pollutants and autism. In previous years when causes of ASD were a mystery in the medical field, genes and family history have been the easy scapegoat.

According to the U.S. Centers for Disease Control and Prevention (CDC)  , in 2014, there are around 1 in 68 American children with autism. This is a sharp increase from the 1 in 150 children in 2000.

As for their methodology, the research team interviewed 217 families from Pennsylvania with children suffering from autism. The children were all born between 2005 and 2009 and were living with their families in the following areas: Allegheny, Butler, Armstrong, Beaver, Westmoreland and Washington.

The team then used the National Air Toxics Assessment (NATA) to estimate exposure to 30 pollutants. They found that children with ASD had a higher exposure to the chemicals styrene (used in plastics and paints and found in burning gas in vehicles), cyanide (from car exhaust and smoking) and chromium (a heavy metal used by power plants and industrial processes such as making steel) than children without ASD.

Dr. Evelyn Talbott, researcher and professor of epidemiology at the University of Pittsburgh, said the results were not coincidental since they were consistent with past studies that showed a link between air pollution exposure and ASD. "We are finding some consistencies between the studies, which I consider to be important," she said. "Is it proving a cause? Absolutely not. But I do think it bears further looking into," as her research team recommended that the findings be further verified through exposure assessment at the individual level.

Autism Speaks defines autism spectrum disorder (ASD) and autism as both general terms for "a group of complex disorders of brain development which are characterized by difficulties in social interaction, verbal and nonverbal communication and repetitive behaviors."

The condition is also associated with intellectual disability, difficulties in motor coordination and attention, and physical health issues such as sleep and gastrointestinal disturbances.

While researchers are slowly shedding light on the real causes of autism, with the environment often seen as a significant contributor in developing the condition in children; it is better to take extra effort not to be exposed to pollutants and chemicals such as cyanide, styrene, and chromium for the benefit of children and the US population in general.