Microplastics in the Human Food System

Humans consume microplastics through the food and beverages we eat and drink. The objective of this research was to measure microplastics in understudied and unstudied United States food products to further inform microplastic exposure estimates from the human diet and identify potential drivers of microplastic contamination in foods. We aimed to understand microplastic burdens in 16 U.S.-sourced products, including commonly consumed seafoods, terrestrial meats and plant-based proteins. We also investigated the influences of processing level, brand and store type on microplastic contamination. We paired our findings with responses from a recent survey led by Ocean Conservancy regarding protein consumption among the U.S. adult population to provide estimates of human microplastic exposure through consumption of these different protein types.

What did we find?

• Microplastic contamination is ubiquitous across protein products as microplastics were present in all protein types and 88% of all samples.
• A variety of particle types were observed, with fibers being the predominant morphology, followed by fragments then rubber particles.
• We found no differences in microplastic burden between different protein types (seafood, terrestrial and plant-based proteins), different brands of the same product type or different stores the products were sourced from (conventional grocer vs. natural/organic grocer).
• Highly-processed products contained significantly more microplastics per gram than minimally-processed products, but not significantly more than fresh-caught products.
• We found no evidence that microplastics in our samples originated from product packaging as few particles in the samples matched the packaging it came in (e.g. clear films for a product packaged in soft clear plastic).
• Exposure per serving of protein: Based on microplastic counts and survey data on U.S. adult protein consumption, we estimate that, for the 16 protein types studied, American adults consume on average 74 microplastics per serving.
• Annual exposure (for single proteins): When considering consumption of only a single protein type, the mean exposure is about 1,500 microplastics annually. The average annual consumption among these products ranges from 140 microplastics per year for chicken breast to 12,800 microplastics per year for breaded shrimp.

Annual exposure for the totality of all products studied: Based on average reported protein consumption by adults in the U.S. and the average microplastic burden per protein studied, we estimate an American adult will consume, on average, 11,500 microplastics per year. Annual exposure could be as high as 3.8 million microplastics per year if based on average reported protein consumption, but employing the highest levels of microplastics found in each individual protein type.

Public Perceptions of Plastic Pollution

Understanding how the general public perceives topics about plastic pollution and solutions can inform actions to prevent plastic pollution, tailor a focus toward policies with the most community support and identify areas where increased public knowledge is needed. In 2021, Ocean Conservancy led a survey of 1,960 U.S. adults and 882 Ocean Conservancy-connected individuals to gather insights on the knowledge, perceptions and concerns about threats to the ocean, with a specific focus on plastic and microplastic pollution. This research aimed to provide data for the U.S. population from which future studies can measure evolving attitudes and behaviors. The survey aimed to better understand:

• Perceptions of ocean health and threats.
• Perceptions of ocean plastic pollution and impacts.
• Perceptions of microplastic pollution and impacts.
• Opinions about who bears responsibility for actions to tackle plastic and microplastic pollution.
• Willingness to take individual actions to tackle plastic pollution.

Responses from the U.S. adult survey group were also compared to U.S. Ocean Conservancy members who are highly attuned to ocean issues. Overall, our survey results provide new insights into public understanding of ocean threats and plastic pollution, willingness to participate in individual plastic-reduction actions and support for needed solutions. These findings can be used to support policy actions to reduce plastic pollution, aid in communication about various facets of the issue and inform future prevention of plastic pollution.

What did we find?

• Plastic pollution was the primary ocean concern identified by both U.S. adults and Ocean Conservancy members, surpassing eight other threat categories including oil spills, chemical and nutrient pollution and climate change.
• Broad concern was reported about the impacts of ocean plastics on marine wildlife, with human health and coastal community impact concerns being less prominent.
• About half of U.S. adults and 90% of Ocean Conservancy members had heard of microplastics.
• Both study groups indicated widespread support for microplastic pollution prevention measures in the U.S. and believed industry (plastic manufacturers and producers) to be most responsible for taking action to address it.
• Ocean Conservancy members were generally better informed and more concerned about plastic pollution impacts and microplastics compared to overall U.S. adults and reported significantly greater levels of personal action to reduce their plastic footprint when compared to U.S. adults.
• In general, U.S. adults reported a willingness to refuse single-use plastics, but less frequently brought personal takeout food containers to restaurants or contacted local representatives or businesses about reducing plastic waste and pollution.