Plastic’s lengthy thousand-year degradation process is often highlighted as one of the main concerns with plastic pollution. However, the microplastic particles left in the ecosystem have significant detrimental impacts on one’s health. Thankfully, there is indication that science and technology advancements can allow for biodegradation of plastics with no health impacts. Genetic modification presents an opportunity for biodegradation of multiple types of plastics.
A 2017 study found that plastic’s multifunctional capabilities have allowed for its wide usage around the world with an estimated production of 6300 million metric tons since the beginning of mass production until 2015. The micro and nano plastic particles left behind from plastic degradation can then enter the terrestrial and marine food chain via inhalation and ingestion. The absorbed plastic nanoparticles with low toxicity start accumulating in the brain, liver and other tissues. Studies suggest the built-up toxicity will cause harmful effects to the central nervous and reproductive system.
Plastic products are thrown away beyond nature’s absorption capacity. These accumulated plastic products can be seen everywhere including the pacific garbage patch — a famous example which now spans hundreds of kilometres. These microplastics are ingested by aquatic animals and slowly degrade in the gastrointestinal tract. The toxicity responses vary among aquatic life, altering behaviour in fish, impairment to filter feeders as well as damage to metabolism and the cell structure in both a study on the topic found. Currently, the toxic levels in mammals have caused local inflammation responses and studies conducted in laboratories imply an increase in toxicity levels caused by plastic nanoparticles would affect the immune system and cause severe gut inflammation. At this stage, we can survive this global issue since the toxicity levels have yet to reach fatal levels scientist Wright and Kelly said in their 2017 article.
Several actions were taken to stop the growing global issue of plastic pollution but none will tackle the health implications related to plastic degradation. The hierarchy of waste management recommends more sustainable plastic waste management ways such as reduction, recovery, and recycling. Using alternative materials other than plastic is an example of reducing the amount of plastic waste. Incorporating previously used plastic into other goods is one way to recover plastic waste. Promoting the recycling of plastic waste can significantly help achieve a more sustainable plastic waste management. These methods slow the rising toxicity levels due to the degradation of plastic nanoparticles inside the gastrointestinal tract. Prevention can halt the increase in the toxicity levels altogether.
A promising prevention method is genetic modification of the gut bacteria inside the waxworms and mealworms responsible for biodegradation of polyethylene and polystyrene respectively. The biodegradation leaves a pure organic waste containing zero micro and nano plastic particles, the research found. Advances in genetic modification technology allow for the detection of polyethylene biodegradation gene sequences in the gut bacteria of the waxworm. New technology will allow for the gene sequence responsible for polyethylene biodegradation in waxworms to be expressed in mealworms. The creation of a genetically modified mealworm, capable of biodegradation of all plastic forms would be a crucial step towards a less toxic future. The genetically modified gut microbiota will be capable of biodegradation of all plastic types, halting the increase in toxicity levels in the food chain. The lower the toxicity levels in the food chain, the lower the negative effects on human’s immune system alongside lower inflammation effects of the gastrointestinal tract.
Many believe the best way to move forward is to stop the usage and production of plastics altogether. Efforts have been made to tackle the growing plastic pollution problem such as presenting more environmentally friendly alternative materials and plastic waste management methods. While these are great efforts to stop the addition of further plastic into the ecosystem, none will stop the rising toxicity levels in the food chain due to the degradation of plastics into microparticles. The degradation will have direct effects on the central nervous and reproductive systems.
Canada said it will ban harmful single-use plastics as of 2021 under the Canadian Environmental Protection Act alongside further steps to reduce plastic waste. Some of these steps include reducing plastic microbeads in freshwater marine ecosystems. These efforts are great ways to move into a plastic-free future, however, they disregard the existing related health implications. Canada must allow more funding, resources and research opportunities for plastic biodegradation methods such as the development of genetically modified species, including mealworms.