On August 19, 2024, Sarah Dunlop and other researchers from the Minderoo Foundation and the University of Adelaide in Australia published a comprehensive review of the research concerning links between exposures to chemicals commonly found in plastics and human health effects. The umbrella review, published in Annals of Global Health, evaluated 52 systematic reviews, covering 759 meta-analyses, and found that many plastic-associated chemicals, including bisphenol A (BPA, CAS 80-05-7) and phthalates, are linked to serious health outcomes. “Exposure to plastic-associated chemicals is associated with adverse outcomes across a wide range of human health domains,” the authors conclude.
An umbrella review synthesizes findings from multiple meta-analyses or other systematic reviews. It is considered one of the highest levels of evidence synthesis, providing a comprehensive overview of the existing literature on a particular subject.
This umbrella review focused on several major classes of plastic-associated chemicals. Bisphenols, phthalates, and per- and polyfluoroalkyl substances (PFAS) are widely used in food contact applications as metal coatings, plasticizers, and in non-stick cookware, respectively. Other chemicals included in the review were flame retardants, including polybrominated diphenyl ethers (PBDEs), and polychlorinated biphenyls (PCBs) which while generally npt added to food contact materials deliberately, are still sometimes detected (FPF reported also here).
The study linked these chemicals to a variety of health hazards. “We find that each chemical group with available meta-analysis or pooled-analysis data is associated with at least one adverse human health impact within the broad categories of birth, child and adult reproductive and endocrine, child neurodevelopment, nutritional, circulatory, respiratory, skin-related disorders and cancer outcomes,” the authors say.
BPA is associated with metabolic disorders like type 2 diabetes and cardiovascular disease (FPF reported). Phthalates are linked to reproductive health issues, such as spontaneous pregnancy loss and decreased sperm quality (FPF reported). PBDEs are connected to neurodevelopmental problems in children, while PCBs are associated with cancers and cardiovascular conditions. PFAS exposure was found to increase risks for obesity, ADHD, and allergic conditions, posing significant risks across multiple health domains (FPF reported).
The review emphasizes a need for regulations and monitoring of these chemicals post-market, especially given their prevalence in food-related and other consumer applications. Stating, “safety cannot be assumed at the point of entry of a chemical to market, without process to systematically monitor for and identify post-market toxicity.” Something that other researchers have recently called out the US federal government for failing to do (FPF reported).
The authors pointed out significant gaps in the research, particularly concerning microplastics and polymers, for which no meta-analyses were available. “Large gaps remain for many plastic-associated chemicals,” the researchers noted, emphasizing the need for further research on less-studied substances such as replacement plasticizers and flame retardants.
The authors also advocated for more stringent safety regulations on plastic-associated chemicals, stating that “safety for plastic-associated chemicals in humans cannot be assumed at market entry.” They called for independent, systematic hazard testing and biomonitoring of these chemicals to detect potential harms that may arise post-market.
Recent research by the Food Packaging Forum found 3601 food contact chemicals have been detected in humans. This includes 194 detected in human biomonitoring programs, with 80 of these having hazard properties of high concern (FPF reported).
Overall, the Australian study encourages global cooperation in both research and regulation to mitigate the health risks posed by exposure to plastics. The researchers recommend that future studies focus on emerging concerns such as microplastics and newer chemical additives.
Reference
Symeonides, C., Aromataris, E., Mulders, Y., Dizon, J., Stern, C., Barker, T.H., et al. (2024). “An Umbrella Review of Meta-Analyses Evaluating Associations between Human Health and Exposure to Major Classes of Plastic-Associated Chemicals.” Annals of Global Health. DOI: 10.5334/aogh.4459.
