Women who are exposed to work at 1.5 times more likely to have a child with autism, and new study suggests.
The recent surge in cases of autism – which now affects one in every 68 children in the US – suggests that something more than genetic inheritance is at play.
But autism remains a fairly mysterious condition. Its severity exists on a wide spectrum, its cause is unknown and its risk factors are many and various.
New National Institute for Occupational Safety and Health (NIOSH) research uncovered on strong link between autistic children and mothers who work industrial jobs that expose them to potent chemicals.
The study authors think that, while these children are still in the womb, they are exposed to the same toxins their mothers are, and it may alter their brain development.
Exposure to high levels of powerful solvent chemicals at work is linked to a 1.5-fold higher chance women will have children with autism in new government 19659009] In more than 20 years, the number of eight-year-olds who are on the autism spectrum has more than doubled.
In 2000, autism affected about one in every 150 US children.
But 2014, that number had shot up to one in every 59 children.
As for why, that's a question for a great deal of debate.
Scientists are fairly certain that genetics have something to do with autism, which is more likely to affect a child who has a sibling on the spectrum.
From there, risk factors are a loose, disjointed network. Autism is more common in boys, children and older parents, and children with intellectual disabilities and children do not get diagnosed until after age, but there is no cut-off age.
After much controversy, the scientific community has ruled out the fact that vaccines are a risk factor much less for autism.
Some attribute the rapid increase in cases to simple awareness. Kids are more likely to get diagnosed with autism if their parents or health providers know about the disorder.
But most experts say there are environmental factors at play.
Studies suggest that pollution and other toxins may cause epigenetic or even microbiome changes that raise autism risks.
The NIOSH team decided to look at solvents, a wide and potent class of chemicals used in many industries, running the gambit from food manufacturing to plastic, engineering to dry cleaning and printing to pharmaceuticals.
Proper protective gear is crucial when working with solvents which can be carcinogenic, toxic to the brain, and contribute to infertility.
According to NIOSH, 'millions of US workers' are exposed to them.
The powerful chemicals can get into anyone's system via skin contact, inhalation and body in a long time.
We already know that solvents have been linked to reproductive disruption, and it may be that they impact a baby developing in the womb.
So the increase seen in the last 20 years may be occurring as women who were exposed to these chemicals decades prior – before tighter regulations – were having children.
The new study, published in the journal Occupational and Environmental Medicine, looked at data on the chemical and environmental exposures affecting 750 US mothers and 891 US fathers.
Although they took into account asphalt, metal, pesticide, plastics, radiation, disinfectants and more, solvents had the most significant effects on their exposures, most closely related to their children's autism risks.
The mothers of children on the autism spectrum had been exposed to more than women with children who did not have autism.
And those who had been exposed to higher levels of solvents at work were 1.5 times more likely to have children with autism.
Women who faced 'moderate intensity' levels of exposure were almost twice as likely to have a child on the spectrum.
The researchers merely monitored their subjects, so their findings do not explain why these women might be more likely to have children with autism.
'However, these results are consistent with earlier reports that have identified solvents as a potential risk factor for [autism spectrum disorders],' the researchers said.