Common plastic additive linked to autism-related and ADHD symptoms

The study found that higher levels of DEHP detected in mothers’ urine during pregnancy were associated with epigenetic changes in more than 500 genes in umbilical cord blood, as well as behavioral outcomes in children at ages two and four.

According to New Atlas, DEHP is widely used in numerous everyday products. However, because the study was observational, its findings cannot establish a definitive cause-and-effect relationship. Experts emphasize that neurodevelopmental disorders have multiple contributing factors, but the findings highlight the need for stricter government regulations on plastic safety to protect vulnerable populations.

DEHP is commonly added to plastics to increase their flexibility. The chemical may also affect genes involved in brain development, potentially contributing to autism-related and ADHD symptoms.

Avoiding exposure to additives such as DEHP can be difficult in everyday life. These chemicals are found in products ranging from hoses and raincoats to medical equipment and plastic food bags. DEHP belongs to a group of chemicals known as phthalates and is added to polyvinyl chloride (PVC) to make it easier to manufacture into soft, flexible materials.

Phthalates can also mimic or interfere with chemicals in the human body that are essential for hormone production. They have been associated with lower testosterone levels and reduced sperm quality, while researchers have also suggested that they may affect neurobehavioral outcomes in children.

The researchers identified a strong association between a network of more than 500 epigenetically altered genes, DEHP exposure levels and behaviors associated with autism and ADHD.

Further analyses of dozens of independently collected blood samples, along with postmortem brain tissue samples, supported the researchers’ conclusion that DEHP exposure may alter gene expression. Nevertheless, the observational design of the study limits its ability to demonstrate causality.

Autism, ADHD and other neurodevelopmental disorders are multifactorial conditions that arise from a combination of numerous genetic and environmental factors. Therefore, it is unlikely that a single exposure such as DEHP, on its own, would substantially alter a child’s risk.

At the same time, parents have limited control over exposure to such chemicals. If a common plastic additive has even a small potential to subtly affect neurodevelopment, pregnant women may have little practical ability to avoid exposure.

Chemical exposure is largely determined at the population level and cannot easily be treated as a matter of individual choice. Chemicals such as DEHP can enter the body through ingestion, making government safety regulations governing food processing and packaging particularly important.

Global efforts to regulate plastics should take into account emerging evidence on the need to protect human health, especially among vulnerable groups such as pregnant women and young children.