Clearly Contaminated: Using Phase Contrast Microscopy to Reflect Microplastic Reality

In recent years, the presence of microplastics in drinking water has become more apparent – and pressing. All Canadians ingest these particles, yet there remains little data on their impacts on human health and the full scope of this situation. The aim of this project is to assess the microplastic levels in three qualities of water and determine whether or not the current water treatment systems used affect the amount of microplastics in drinking water. The results from this project suggest that the current multi-barrier treatment system is not sufficient enough to remove the majority of microplastic particles from the drinking water that was tested. If the Town of Bridgewater were to update current water quality standards/treatment system, then community citizens would have access to higher quality drinking water regardless of whether community citizens can afford any filters that reduce microplastics. Despite minimal research on the impacts of micro/nanoplastic particles (MNP) on human health, it can be concluded that the chemicals – such as phthalates, dioxins and bisphenols – leaching out of plastic have negative impacts on people’s health. In spite of this, MNP aren’t in The Guidelines for Canadian Drinking Water Quality.  This project aims to increase awareness: the community’s awareness of the presence of microplastics in town drinking water; the awareness of the importance for the town to begin MNP testing and monitoring regardless of national guidelines; and to investigate systems that would reduce MNP levels, while setting an example for other communities in MNP reduction.

The background research for this project encompassed reading numerous documents regarding several aspects of the project, inquiries to an industry expert, as well as a professor at Acadia University. Trustworthy sources like the World Health Organisation were identified by confirming facts – inhaling MNP may result in harm to the respiratory track – between multiple established sources such as SafePipingMatters.org and Lung Foundation Australia, checking for citations, and examining government documents.

This experiment was conducted at SMU on February 20 2026.

Experiment procedure; collect three samples of water from a local  residence (unfiltered), a local school (filtered) and high purity lab water from the SMU lab. Next, set up equipment/materials and prepare the slide for the samples. After that, inverse the jar three times and hold for three seconds each time. Immediately following this, use a glass pipette to place the sample on  the slide, and place a coverslip over the sample. Observe the sample using phase contrast optics. Use a phone to take a photo through the ocular lens, then use the stage controls to move the objective lens to two more locations on a horizontal plane. Make sure to take a photo in each new location. Dispose the coverslip and pipette. Repeat this process for every sample.

Three drops from each type of water are analyzed, each drop in three different locations. This yields twenty-seven different samples. Collect the data by calculating the volume of water, counting the number of plastic particles in each image, and their sizes. Put the data into a spreadsheet and then use it to construct multiple graphs.

The variables are controlled by testing the samples in the same environment, employing the same materials and procedure, and by ensuring all tools/materials that come in contact with the samples are glass, or non-plastic.

Three types of water were tested: Unfiltered (tap), HPL (high purity lab), and Filtered (Oasis Fountain). From each water type, 3 samples were taken. For each sample, three photos were taken at different locations on the microscope slide on a horizontal plane. That’s 9 readings per water type, 27 readings total — each split into two size categories. Each field of view (FOV) contained 0.00314μL of water. All the particles were counted in each reading, and classified as either large (>10 µm) or small (<10 µm).  This is because research shows that smaller microplastics (<10 µm) are more dangerous because they can cross biological membranes and enter cells. All samples contained microplastic particles.

Unfiltered had the highest amount of total particles (mean 133.33), Filtered followed (mean 121.89), HPL contained the least (mean 40.33). Looking at small particles, the Unfiltered water (mean 122.33) contained the most, followed by Filtered water (mean 118.89), and then HPL water (mean 37.56). To determine whether the following numbers had a significant difference or whether it was just chance, an ANOVA test was used (p = 0.004). Because this data is variable and a few high readings are pulling the average up, this data is statistically insignificant for small particles.

Looking at large particles, the results suggest that Unfiltered water contains the most (mean 11), Filtered water (mean 3), and HPL water (mean 2.78). Approximately 4x more large particles were found in Unfiltered water. These statistics were found using a one-way ANOVA, because it can compare 3+ groups at a time, a Kruskal Wallis test confirmed the ANOVA result. A pairwise t-test (p = 0.004) found there was a statistically significant difference between the Unfiltered vs HPL (p = 0.011) and Unfiltered vs Filtered (p = 0.017). There was not a statistically significant difference between the Filtered vs HPL – this means that Unfiltered water contains significantly more larger particles than both other samples. This test was used because it compares each pair separately.

The effect sizes (Cohen’s d) between Unfiltered vs HPL (1.36) and Unfiltered vs Filtered (1.26) were very large, however, the effect size between HPL vs Filtered (0.08) was negligible. The Cohen's d test was used to determine whether the difference between the mean of large particles was significant.

This experiment showed that each water quality tested all contained microplastics, and highlighted the full extent that microplastics are pervasive in town drinking water. The results from the pairwise t-test suggest that the extra filtration does make a difference in the amount of large particles in drinking water. These results apply to the real world because water is integral to everyday lives; people need it to survive, it flows into the plants and animals that are consumed. If knowledge increases about microplastics: how they get in drinking water, how to eliminate them as best as possible, and the adverse health effects such as respiratory issues, cardiovascular diseases, chronic inflammation, hormonal disorders, amplified development of antibiotic resistant pathogens, and cell death. “The internal organs that are most commonly affected are the liver, the kidneys, the heart, the nervous system (including the brain) and the reproductive system” (Campanale, et al, 2020) - then solution focussed thinking can take place at the consumer, production, corporation and regulatory levels. For example, the pipes in the Town of Bridgewater are an estimated 40-50% PVC which deteriorate at 20-30 years of age, some of which are approximately 30 years old. Being aware of such contributors can help isolate the problems, and inspire action based solutions. Consumers can take steps to reduce microplastics by supporting companies that use sustainable packaging/products, use glass/metal containers, thrift and buy sustainable clothes. The government could support funding for effective filtration systems, increase reliability of microplastic monitoring, and implement guidelines.

This project could be improved by testing a greater variety of water qualities including well water, the watershed, bottled water, water from the Town of Bridgewater watershed, and water pre-treatment. During the testing, a different slide would be used for every sample to ensure cross contamination didn’t occur between samples. Next steps include testing the qualities of water listed above to get a better understanding of which areas of the treatment/distribution system require improvements. Additionally, the results from this experiment will be presented to the Town of Bridgewater Council to continue raising awareness, and advocating for microplastic-specific filtration.

I owe a big thanks to multiple people for helping me with this project. I’d like to acknowledge David Dansereau at SMU for providing me with the equipment, materials, and space to perform my testing; Russell Easy at Acadia University for helping me find resources on methods of identifying microplastics; Graham Mann for giving me feedback on my project and helping with statistics, and Madison Greek for giving feedback as well. Finally, my parents, who provided me with moral support the entire way through my project.

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