The Effects of Personal Protective Equipment Pollution on Marine Ecosystems Through the Lens of Phaeodactylum tricornutum
The ongoing development of COVID-19 means that many of the social, economic, and environmental impacts have yet to present themselves. As the first modern pandemic of global proportions, it has impacted, and continues to impact, the very nature of how humans function and interact with one another and the environment. One such consequence that has caught the attention of researchers is the increased use of personal protective equipment (PPE), specifically the increased pollution it has caused. A study conducted by Haddad et al. in Agadir, Morocco, focused on this topic. Data collected at several coastal locations, both during and after lockdown, was used to demonstrate the direct effect the use of beaches had on ocean pollution. Roughly 95.5 percent of the PPE identified was collected after the lockdown in Morocco ended and the highest density was accumulated at recreational and surfing beaches (Haddad et al., 2021). The study found that of these PPE items, nearly 97 percent were face masks, with the vast majority being single use masks. In 2020 alone, it was estimated that 1.56 billion face masks polluted oceans (Haddad et al., 2021). Naturally, this excess of PPE pollution has had significant effects on marine environments, especially on microorganisms.
Every aspect of an ecosystem is crucial to its survival and ability to thrive, but few are as important as foundational organisms. One such foundational organism are diatoms, unicellular, microalgae found in oceans, rivers, and soils across the globe (Wikipedia, 2022a). Their importance becomes apparent when understanding that they create 20 to 50 percent of the earth’s oxygen every year (Wikipedia, 2022a). Phaeodactylum tricornutum (P. tricornutum) is an abundant diatom first described in 1897 (Wikipedia, 2022b). They are unique in that they are the only species in the Phaeodactylum genus that can alter their shape based on their environment and do not require silicon to survive (Wikipedia, 2022b). It is one of three diatoms to have its full genome mapped, and when analyzing the data, it is shown to have a large ratio of prokaryote-based genes (Wikipedia, 2022b). Its ability to grow quickly and its natural use as an energy source makes it a great candidate for biotechnology and research.
A study conducted by Sendra et al. focuses on the use of P. tricornutum to understand the full extent of PPE pollution. The study examined the difference between whole and fragmented masks and the cytotoxicity they cause to P. tricornutum (Sendra et al., 2022). Figure two of the research article gave a comprehensive breakdown of the biomedical assays conducted and the results. Initially the study conducted analysis of the water and surgical masks to determine their individual assays. Panel A of the figure contained the results of Fourier transform infrared spectroscopy (FTIR), which is a test that quantifies the amount of absorption or emission a substance has. This provides a baseline for the researchers to compare with future results. Panel B was a graph and image showing the size range of face mask fragments used in the respective portion of the experiment. Panel C shows that the layers of surgical masks contain toxic microfibers and metals including aluminum, silicon, phosphorus, iron, copper, manganese, zinc, and barium; when put in kinetic aquatic environments they release as micro or nano-plastics (Sendra et al., 2022). In the study, control water, water with whole masks, and water with fragmented masks were shaken for a month, then chemically analyzed for the aforementioned cytotoxins. These waters were then used to grow P. tricornutum in order to determine how the pollution affected its growth, according to cell density and size (Sendra et al., 2022).
The results were shown in figure 2, panel D through G. Panel D provides a bar graph showing the elements released in the water overtime, notably manganese, zinc, and nickel were elements that showed statistically significant increases of release (Sendra et al., 2022). Panel E is another FTIR that shows the functional groups found after the experiment. Finally, panels F and G show the amount and size of fragments and fibers released, respectively. Overall, the results from FTIR and toxicological and bioassays showed that the fragmented face mask solution contained more released toxins and fibers than the other two samples (Sendra et al., 2022). Fragmented masks decreased cell density by 53.09 percent and overall size (Sendra et al., 2022). Moreover, fragmented masks led to a dose-dependent decrease where during the 48 hour time interval the cell density was decreased, but recovery was observed in cell population at 72 hours (Sendra et al., 2022). After 48 and 72 hours, cells exposed to whole face masks showed a decrease in cell complexity which affected the photosynthetic and internal properties of the cells (Sendra et al., 2022). However, the study mentioned that while cell recovery was present it is important to recognize the unlikelihood for this to occur naturally because microalgae are a more sensitive taxon.
These results and the study’s discussion build largely into possible future applications. The methodology was well structured with explanations that give the study itself high reproducibility. As cited earlier, the effects that other species could have on the results is incredibly important and should be considered for future research, as it gives new studies a place to expand on their work. The continued research into how PPE as a new pollution contributor affects ecosystems as a whole is integral to understanding the environmental impacts of COVID 19.
References
Wikipedia contributors (2022a) Diatom. Available at: https://en.wikipedia.org/wiki/Diatom.
Wikipedia contributors (2022b) Phaeodactylum tricornutum. Available at:
https://en.wikipedia.org/wiki/Phaeodactylum_tricornutum.
Haddad, M.B. et al. (2021) “Personal protective equipment (PPE) pollution associated with
the COVID-19 pandemic along the coastline of Agadir, Morocco,” Science of the Total Environment, 798, p. 149282. Available at: https://doi.org/10.1016/j.scitotenv.2021.149282.
Sendra, M. et al. (2022) “Products released from surgical face masks can provoke
cytotoxicity in the marine diatom Phaeodactylum tricornutum,” Science of the Total Environment, 841, p. 156611. Available at: https://doi.org/10.1016/j.scitotenv.2022.156611.
By: Joy Brewer
November 15, 2022
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