Microplastics? More like macro-problem

Take a moment to look at the space you’re in and see just how many plastic items surround you. They might be the container holding the fruit you’re snacking on, the plastic bag with your laundry quarters, or the lid of your water bottle. What you might not see is the plastic you are eating; it’s estimated that we consume a “credit card” worth of microplastics every week. This problem will only get worse as plastic production is expected to triple by 2060.

First Report from the New CalSPEC 

This growing problem is why the California legislature asked the new California State Policy Evidence Consortium (CalSPEC) to write a report on how microplastics in the environment are impacting health and what governments have done to address this problem. Led by UC Sacramento, CalSPEC gathers experts from the University of California (UC) system to address policy questions of interest to the state legislature with a non-partisan, evidence-driven report.

The Program on Reproductive Health and the Environment (PRHE) led the health impacts section of the report with a rapid systematic review (rapid review) of nearly 2,000 studies on how microplastics affect health.

Primary and Secondary Microplastics 

Microplastics – plastics not visible to the human eye that we ingest without knowing – are either intentionally created (primary microplastics) or a result of deteriorating larger plastic products, like plastic bags or tires (secondary microplastics). The concerning thing about these microplastics is that they are small enough to exist undetected in our food, air, and water – which means they can easily be inhaled or digested, have been found in human breast milk, placenta, and stool, and exposure to them can lead to biological changes. 

Microplastics harm reproductive, respiratory, and digestive systems 

Using the Navigation Guide systematic review method to evaluate the science, PRHE found evidence that microplastic exposures appear to harm fertility as well as induce biological changes that are markers for increased cancer risk in the digestive tract. The report’s preliminary findings also indicate that microplastics harm respiratory health. 

These health harms could very well be the tip of the iceberg. We focused our rapid review on reproductive, digestive, and respiratory outcomes, which capture just a fraction of the health issues outlined in the microplastics studies found in our search. Beyond this, microplastics have been increasing in the environment for quite some time and now science is catching up to reveal the impact they are having on our health.   

What can be done about our plastic problem?  

At a state level, the evidence from our rapid review supports California legislators in acting on this information and implementing policies to reduce microplastic contamination.

There is also opportunity at the federal level right now to lessen the health risks from microplastic exposure. The next set of chemicals the EPA will evaluate under the Toxic Substances Control Act (TSCA) contains multiple petrochemicals, including phthalates, used in the production of many common plastic products, which have the potential to degrade into microplastics. TSCA, which is the law that regulates chemicals in commerce, will therefore be a critical policy lever to identify and prevent health harms to human and ecological health from increased plastics production. 

About the Author

Courtney Cooper, MPH is a Science Associate for the Science & Policy team, working to promote evidence-based decision making and best practices for systematic reviews in environmental health. She graduated with a BS in Public Health and Minor in Dance from the University of South Carolina and received an MPH from the University of San Francisco. She is interested in advancing maternal, reproductive, and environmental health.