Women exposed to industrial chemicals including metals and pesticides while pregnant are more likely to have autistic children, study finds
- Researchers looked for evidence of industrial chemicals in Canadian women
- They found metals, pesticides, PCBs and BPS chemical were linked to autism
- They discovered the link by looking at autistic traits in pre-school children
Women who are exposed to industrial chemicals while pregnant, including metals and pesticides, are more likely to have autistic children, according to a new study.
Simon Fraser University researchers measured levels of 25 chemicals in blood and urine samples from 1,861 Canadian women during the first trimester of pregnancy.
They found a direct link between increased autistic-like behaviours in pre-school aged children and exposure to certain environmental toxicants during pregnancy.
The toxins that led to autistic-traits in children include metals, pesticides, polychlorinated biphenyls (PCBs), phthalates, and bisphenol-A (BPA).
Study authors couldn’t say why the link exists or what causes it, adding that more work would be needed in future to explore it in more detail.
Simon Fraser University researchers measured levels of 25 chemicals in blood and urine samples from 1,861 Canadian women during the first trimester of pregnancy (stock image)
ALMOST 2% OF BRITS ARE AUTISTIC
Socially disadvantaged British children of ethnic minorities are more likely to experience autism, study reveals.
According to University of Cambridge researchers, 1.76% of children in the UK are on the autistic spectrum.
But black and Chinese pupils are 26% and 38% more likely to be autistic, respectively, compared to white children, they say.
Pupils with a record of autism in schools were 60 per cent more likely to also be socially disadvantaged.
Autism Spectrum Disorder (ASD), which is characterised by impaired social communication and stereotypic behaviours, affects 1-2% of children.
To get a picture of the impact chemicals have on pregnancy and young children the Canadian team used data from the Maternal-Infant Research on Environmental Chemicals (MIREC) Study, a pregnancy cohort from ten Canadian cities.
Study staff recruited women during the first trimester of pregnancy between 2008 and 2011, with follow up surveys and check ups as the children grew older.
‘We measured child development outcomes in a convenience subsample of 600 children born to these women when they were 3-4 years old,’ the team said.
When participating children were 3-4 years old, their parents completed a preschool-aged version of a questionnaire designed to identify autistic-traits.
The sum of responses to the survey gives a child’s T-score, where higher scores indicate a greater number and intensity of ASD-like behaviours.
The researchers found higher maternal concentrations of cadmium, lead, and some phthalates in blood or urine samples were associated with increased scores, and were particularly strong among children with more autistic-like behaviours.
They found a direct link between increased autistic-like behaviours in pre-school aged children and exposure to certain environmental toxicants during pregnancy
Authors also used the Social Responsiveness Scale (SRS) questionnaire, which gives an indication of stereotypical behaviours seen in autistic children.
‘Our results suggest that children with the most autistic-like behaviours, who are of greater clinical interest, appear to be particularly susceptible to these toxicants,’ the team explained.
The study’s lead author, Josh Alampi, said the work highlights ‘the relationship between select environmental toxicants and increased SRS scores.’
‘Further studies are needed to fully assess the links and impacts of these environmental chemicals on brain development during pregnancy,’ he added.
The results were achieved by using a statistical analysis tool, called Bayesian quantile regression, that allowed investigators to determine which individual toxicants were associated with increased SRS scores in a more nuanced way.
‘The relationships we discovered between these toxicants and SRS scores would not have been detected through the use of a means-based method of statistical analysis (such as linear regression),’ noted Alampi.
‘Although quantile regression is not frequently used by investigators, it can be a powerful way to analyse complex population-based data.’
The findings have been published in the journal American Journal of Epidemiology.
THE SIGNS AND SYMPTOMS OF AUTISM
According to the Centers for Disease Control and Prevention, people with autism have trouble with social, emotional and communication skills that usually develop before the age of three and last throughout a person’s life.
Specific signs of autism include:
- Reactions to smell, taste, look, feel or sound are unusual
- Difficulty adapting to changes in routine
- Unable to repeat or echo what is said to them
- Difficulty expressing desires using words or motions
- Unable to discuss their own feelings or other people’s
- Difficulty with acts of affection like hugging
- Prefer to be alone and avoid eye contact
- Difficulty relating to other people
- Unable to point at objects or look at objects when others point to them