Beware of the plastisphere
Plastic waste is more dangerous than we think. It harbors microbes that could be lethal to people and natural ecosystems. With more than five billion tons of plastic waste buried or floating around on our planet, we must pay attention.
Around a decade ago, microbial ecologist Erik Zettler coined the term “plastisphere” to refer to the thin film of microbial community attached to plastic and distinct from its surroundings. He observed that plastics floating in the ocean attract various microorganisms, such as algae and bacteria. Since plastics persist for a long time, they can transport associated microbes long distances in the oceans. These alien microorganisms can disrupt native microbial populations and, consequently, larger marine life that depend on them.
Since then, a growing body of knowledge has illuminated the characteristics and dangers of the marine plastisphere. According to Li and co-writers in their paper in Nature (2024), 80,000 diatoms were found in just one square centimeter of marine plastics. Another study reported that one gram of plastic in the ocean has 10 times more microbial biomass than a cubic meter of ocean water. Even more alarmingly, the plastisphere harbors different pathogens, such as viruses and antibiotic-resistant bacteria, that threaten the health of plants, animals, and humans. These microbes are found to be rare in the surrounding water but abundant on the surface of plastics.
In another paper, Li and others (The Innovation, 2024), pointed out that “the plastisphere distinguishes itself from natural habitats by selectively recruiting microbial communities and generating new coexistence patterns.” This difference could lead to changes in nitrogen cycling, greenhouse gas emissions, and novel pathogens with implications for food safety and human health. The terrestrial plastisphere is less known and could be as perilous as its marine counterpart. For example, Sun and co-workers (2024) found out that fungal populations differ between soil plastisphere compared to the surrounding environment. The authors suggested that the plastisphere could be considered a global threat to human health.
Closer to home, the Philippines holds the dubious distinction of being the largest ocean plastic polluter in the world. Part of the reason for this is our penchant for using small, single-use plastic containers. A 2024 World Bank report prepared in partnership with the Department of Environment and Natural Resources pointed out that in 2019, we used “more than 163 million plastic sachets, 48 million shopping bags, and 45 million thin-film bags.”
We have enough laws to manage plastic waste, primarily Republic Act No. 9003 or the the Ecological Solid Waste Management Act of 2000 and RA 11898 or the Extended Producer Responsibility Act of 2022. Indeed, it is encouraging to note that hundreds of local government units have passed ordinances regulating the use of plastic bags in commercial establishments. In addition, the government is targeting the elimination of plastic pollution by 2040. The roadmap to 2040 has three pillars: closing plastic leakage pathways, enabling plastic recycling, and managing plastic demand.
Under the first pillar (short term), the plan aims to reduce non-recyclable single use plastics and increasing plastic recovery from existing facilities.
Under the second pillar (medium term), the aim is to enhance the local government unit’s capacity to carry solid waste management while increasing the production of recyclables.
Finally, in the third pillar (long term), the goal is to have enhanced design of plastic products, incorporate advanced technologies to manage plastic waste, and shift toward full plastic circularity.
At the household level, we can do our share by making a conscious effort to reduce our use of plastics. One practical way of doing this is by bringing reusable bags when shopping. Another way is to avoid using plastic straws whenever possible. The private sector can likewise contribute massively to reducing our plastic footprint by supporting the 2040 roadmap, among others.
Given our massive plastic waste generation, our scientists should begin investigating our land and marine plastisphere. The knowledge generated will inform our policymakers on the reality and extent posed by such habitats.
With more than 400 million tons of plastic waste generated annually worldwide, the plastisphere is expanding inexorably. As the world dumps more plastic waste, the plastisphere creeps and floats silently in land, rivers, lakes, and oceans. On its surface, unseen colonies of microorganisms, some of which could be deadly to humans, multiply exponentially. Beware.
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Dr. Rodel D. Lasco is the executive director of The Oscar M. Lopez Center, a foundation devoted to discovering climate change adaptation solutions (http://www.omlopezcenter.org/).
