In this era of mass consumption, one particular claim is hard to swallow: we ingest a credit card’s worth of plastic every month.

It’s a concerning image, but it’s unclear how accurate it is or how concerned we should be.

As a result, the Government of Canada invested $2.1 million across three university research teams to determine just how much of a problem it is in terms of human health.

One of those teams is located on Memorial’s St. John’s campus, where Drs. Karl Jobst and Lindsay Cahill in the Department of Chemistry, Faculty of Science, and many of their students are developing a means of measuring just how much microplastics find their way into our bodies from the food we eat, the packaging it comes in and even the air we breathe.

Causal relationships

Dr. Jobst says the researchers are developing analytical methods in their lab to measure microplastics in blood, tissue samples, drinking water and indoor air.

“While there are concerns regarding the potential exposure to microplastics, these exposures are not well characterized,” he said.

Dr. Cahill says they’ll study causal relationships between maternal exposure to microplastics and negative pregnancy outcomes.

They’ll dial in on whether the size and type of plastic matters and what common plastic additives are most harmful.

Below, read a Q&A to delve further into the topic with the researchers.

CP: Why is this work of interest to you and the general public?

Dr. Jobst: Plastics are used everywhere and found in everyday household items, clothing, construction materials and children’s toys.

Virtually everyone is exposed, but estimates of how much we are exposed vary widely.

I think the general public would like to know how much they are exposed and whether this exposure poses a health risk. These are questions we hope to answer as part of the study

Dr. Cahill: We recently conducted a survey of parents or expecting parents in Newfoundland and Labrador about their perceptions towards microplastics.

The majority of people are aware of microplastics and their negative impact on the environment.

However, many were surprised to find out that microplastics have been detected in human tissue and wanted to learn more about the human health impacts of microplastics.

CP: How will you go about conducting your study?

Dr. Jobst: We plan to recruit approximately 100 study participants who are willing to donate blood and placental tissue and allow us to sample the air and water in their homes.

Our group is equipped with a state-of-the-art cyclic ion mobility mass spectrometer that will enable confident identification of microplastics and chemical pollutants, such as plastics additives, embedded in the polymer.

Dr. Cahill: Using cutting-edge biomedical imaging technologies (ultrasound, nuclear magnetic resonance spectroscopy), we will study how microplastics exposure in mice impacts fetal growth, placental function and brain development.

CP: You mentioned plastics additives. Do these additives carry chemicals that could be harmful, in addition to the microplastics themselves?

Dr. Jobst: Plastics contain a wide range of additives to help improve the characteristics of the plastic during manufacturing and use.

For example, plasticizers are added to improve flexibility, and flame retardants are added to reduce flammability.

Some of these chemical compounds are already known to pose a risk to the environment and human health.

For example, TDCPP (Tris(1,3-dichloro-2-propyl)phosphate) is a widely used plastic additive that has been recommended for listing under Schedule 1 of the Canadian Environmental Protection Act because it could be harmful to human health.

CP: What do you envision as a direct result of your research?

Dr. Jobst: Armed with knowledge of the extent of microplastics exposure, we hope to identify the potential association between microplastics exposure and adverse pregnancy outcomes.

Ultimately, the results will eventually assist in establishing guidelines to limit exposure and prevent adverse health outcomes that result from exposure to microplastics.

CP: At the moment, what are the primary concerns about the effects of microplastics on human health?

Dr. Cahill: In mice, our group found maternal exposure to high concentrations of polystyrene microplastics resulted in significant fetal growth restriction, placental dysfunction and brain abnormalities in the offspring.

While these results are concerning, it is critical to better characterize the exposure levels in humans to put these results into context.