Do plastics cause autism? Why new research on BPA has people worried

Worrying new research linking plastics to autism has sparked a call for an overhaul of regulations in Australia.

A breakthrough Australian study published in Nature Communications has for the first time uncovered a possible biological pathway that might help explain the connection between autism and the endocrine-disrupting chemical BPA found in some plastics.

Here’s what you need to know.

What is BPA?

Bisphenol A (BPA) is a chemical found in plastic wrapping, plastic bags and the plastic lining on tins to help protect food from contamination and extend shelf life.

Small amounts of BPA are known to migrate from containers into foods and concerns about potential health impacts have been raised for many years.

BPA is found widely in the environment and is present in most people’s bloodstreams.

Why has BPA been linked to autism?

A new study by scientists at Australia’s Florey Institute found levels of BPA were higher in pregnant mothers who gave birth to sons with autism.

The study examined children with lower levels of the enzyme aromatase who were born to mothers with higher urinary BPA levels in late pregnancy.

It found boys in this group were three and a half times more likely to have autism symptoms by two years old and six times more likely to have a verified autism diagnosis by 11 years old.

While the association between autism and BPA has been known for a while, this new research by Dr Wah Chin Boon and Professor Anne-Louise Ponsonby has identified a biological pathway that might help explain the connection.

“BPA can disrupt hormone-controlled male fetal brain development in several ways, including silencing a key enzyme, aromatase, that controls neurohormones and is especially important in fetal male brain development. This appears to be part of the autism puzzle,” Professor Ponsonby said.

Should I throw out my plastic food containers?

BPAs and other plastic chemicals with endocrine-disrupting effects are widespread and nearly impossible to avoid.

“We all ingest plastic chemicals in many ways — through ingesting plastic food and drink packaging, inhaling home renovation fumes, and through the skin from sources such as cosmetics,” Professor Ponsonby said.

“There are so many ways these chemicals enter our bodies, so, it’s not surprising that BPA was present in a large proportion of the women’s urine samples we studied. It’s important for us to understand how these plastics affect our health.”

The best way to minimise your exposure is to choose BPA-free products and to avoid microwaving polycarbonate plastic food containers such as those used for takeaway as they can degrade after use at high temperatures.

People are also advised to reduce their use of canned foods and when possible opt for glass, porcelain or stainless steel containers — particularly for hot food or liquids.

What is the government doing?

The European Commission has proposed a ban on BPA in food packaging after the European Food Safety Authority (EFSA) in 2023 revealed it had re-evaluated its risk to public health and concluded the tolerable daily intake should be substantially reduced, to 0.2 nanograms per kilo of body weight per day.

A number of countries have since reviewed or are in the process of reviewing the EFSA’s re-evaluation of BPA risk.

Food Standards Australia New Zealand says it is monitoring “the emerging situation with respect to BPA, but notes that previous surveys undertaken in Australia have shown that very few foods contain detectable levels of BPA”.

A voluntary phase-out of BPA use in polycarbonate baby bottles began in 2010.

The Australian Medical Association has called for a review of Australia’s regulation of BPA in the wake of the new findings and the European Food Safety Authority approach.