Plastic Pollution: Earth's Adversary And Our Legacy

Plastic pollution is a pressing environmental issue that poses a significant threat to the planet and all life that inhabits it. The majority of plastic products are not recyclable, with most plastic waste ending up in landfills, the ocean, or leaked into the environment. This has detrimental effects on marine life, with plastic ingestion killing up to 1 million seabirds and 100,000 marine creatures annually. Plastic pollution also affects terrestrial ecosystems, with microplastics contaminating soils and freshwater systems, threatening the health of soil fauna and other organisms. Furthermore, the production and incineration of plastics contribute to climate change and air pollution, impacting human health and the planet's ability to sustain life. Addressing plastic pollution requires urgent global action and a transition towards more sustainable alternatives.

Plastic waste in the ocean

Sources of Ocean Plastic Pollution

Impacts of Ocean Plastic Pollution

The presence of plastic in the ocean has dire consequences for marine life and ecosystems. Plastic debris can cause entanglement and ingestion by marine animals, leading to injury, starvation, and death. Endangered species such as Hawaiian monk seals and Pacific loggerhead sea turtles are among the nearly 700 species affected by plastic litter. Microplastics, which form from the breakdown of larger plastic items, are particularly harmful. These tiny particles can absorb harmful pollutants and release them into the ocean, impacting marine life and potentially entering the food chain. Plastic pollution also affects coastal environments, the fishing and tourism industries, and contributes to the high cleanup costs for coastal communities.

Addressing Ocean Plastic Pollution

To effectively address ocean plastic pollution, a combination of strategies is necessary. Improving waste management systems and recycling practices is crucial, especially in areas with inadequate infrastructure. Reducing the manufacturing and consumption of single-use plastics is essential, as they are a significant source of plastic waste. Additionally, product design should consider the short life of disposable packaging to minimize plastic waste generation. Public awareness and participation in clean-up efforts can also help mitigate the impact of plastic pollution on our oceans.

Plastic waste in the food chain

Plastic waste has entered the food chain, threatening human health and safety. Microplastics, which are plastic pieces smaller than 5mm, are ingested by marine and freshwater organisms, including zooplankton, chaetognatha, ichtyoplankton, copepods, salps, invertebrates, and vertebrates. These microplastics carry toxins and chemicals, which are then transferred to humans when they consume seafood.

Microplastics are spread through the food chain via a process called 'trophic transfer'. Animals carry microplastics in their bodies, and when they are eaten, the microplastics are also ingested. Trophic transfer allows microplastics to move up the food chain, from zooplankton to larger marine animals.

Microplastics are often found in the digestive tracts of fish, which is not usually consumed by humans. However, bioaccumulation in crustaceans, which are filter feeders, is a greater concern as their digestive tracts are consumed. Mussels and molluscs are also good indicators of microplastic contamination as they are consumed whole.

Microplastics have been detected in salt, beer, seafood, bottled water, and human stools. The impact of microplastics on human health is still relatively unknown, but studies have shown that the largest fraction of microplastics is excreted in faeces. However, microplastics smaller than 1.5 µm can penetrate deep into human organs, and nanoplastics can cross the placenta and blood-brain barrier.

The presence of pathogenic microorganisms, such as Vibrio, E. coli, and Bacillus cereus, on plastic debris has raised concerns about new contamination routes for the introduction of pathogens into the food supply. While the survival of these pathogens on plastic debris until the end of the food chain is still unknown, the scientific community has expressed concern about the potential risks to human health.

The global production of plastics is increasing, with an estimated 335 million metric tons produced in 2016. The extensive and indiscriminate use of plastic packaging, bottles, synthetic textiles, car tires, paints, and personal care products are major contributors to microplastic contamination in the environment and the food chain.

Plastic waste in the air

Plastic pollution has become one of the most pressing environmental issues, with production expected to double by 2050. While plastic waste in oceans is a well-known issue, plastic is also a significant contributor to air pollution.

The Extraction of Oil

Most plastics are made from fossil fuels like oil and natural gas, which release toxic emissions when extracted. Oil and gas drilling releases contaminants such as benzene, toluene, carbon monoxide, and volatile organic compounds. Oil refineries require multiple operational stages that emit dozens of pollutants, contributing to smog and toxic air.

The Impact of the Recycling Industry

While recycling is important to prevent virgin plastic production, it can cause air pollution if not done properly. Many "recycled" plastics from the USA, for example, are shipped overseas to South and Southeast Asia, where informal recycling facilities lack safe working conditions and pollution control measures. This results in toxic emissions from melting plastics and unsafe disposal of plastic waste.

Incineration of Plastic Materials

The slow decomposition of plastic is a challenge for landfills, leading to the burning of plastic waste, which releases dangerous substances such as heavy metals, persistent organic pollutants (POPs), and other toxic chemicals into the air and ash waste residues. These chemicals are linked to asthma, endocrine disruption, and cancer. POPs can travel long distances via wind currents, affecting air quality in other regions.

Plastic's Ability to "Off-Gas"

Phthalates, chemicals added to plastic for flexibility and heat resistance, are not chemically bound and can easily off-gas into the air and products we consume. These endocrine disruptors have been linked to health issues such as lower testosterone levels, decreased sperm counts, and reduced female fertility. Microplastics are present in both indoor and outdoor air and can be inhaled, entering the bloodstream and causing cardiovascular and cerebrovascular diseases.

The presence of plastic waste in the air highlights the urgent need to reduce plastic consumption, improve waste management practices, and transition to sustainable alternatives to protect human health and the environment.

Plastic waste on land

The impact of microplastics in soils, sediments, and freshwater could have long-term negative effects on ecosystems. Terrestrial microplastic pollution is estimated to be four to 23 times higher than marine microplastic pollution. One-third of all plastic waste ends up in soils or freshwater, disintegrating into particles smaller than five millimeters, known as microplastics, which break down further into nanoparticles (less than 0.1 micrometers in size). These particles enter the food chain, with sewage being a significant distributor. Sewage sludge, often used as fertilizer, contains thousands of tons of microplastics that end up in our soils each year. Microplastics have even been found in tap water.

The surfaces of plastic fragments may carry disease-causing organisms and act as vectors for diseases in the environment. They can also interact with soil fauna, affecting their health and soil functions. Earthworms, for example, make different burrows when microplastics are present in the soil, impacting their fitness and the soil condition. Additionally, chlorinated plastic can release harmful chemicals into the surrounding soil and water sources, causing potential harm to the species that drink the water, including humans.

Another source of microplastics is our clothing. Washing machines can release hundreds of thousands of microscopic plastic fibers into the environment during each wash cycle. These fibers are then carried off to wastewater treatment plants or discharged into the open environment.

While media attention has largely focused on plastic waste in the oceans, it is clear that plastic waste on land poses a significant threat to ecosystems and human health. More research is needed to fully understand the impact of plastic waste on land-based wildlife and to develop effective strategies for reducing and managing plastic waste on land.

Plastic waste and human health

Plastic waste poses a significant threat to human health, with its impact remaining poorly understood. At every stage of its lifecycle, from extraction to consumer use and disposal, plastic poses distinct risks to human health.

The extraction and transportation of fossil feedstocks for plastic release toxic substances, including carcinogens, into the air and water. Over 170 fracking chemicals used to produce plastic feedstocks have known human health impacts, including cancer, neurological, reproductive, and developmental toxicity, as well as immune system impairment.

The refining and production of plastic resins and additives release highly toxic substances, such as carcinogens, into the air, with documented effects including nervous system impairment, reproductive and developmental problems, cancer, leukemia, and genetic impacts like low birth weight.

Consumer products and packaging can lead to the ingestion and inhalation of microplastic particles and hundreds of toxic substances, with known or suspected carcinogenic, developmental, and endocrine-disrupting impacts. These microplastics have been detected in human blood, lungs, and feces, with scientists urgently trying to determine the extent of their harm to human health.

Plastic waste management, especially incineration, releases toxic metals, organic substances, acid gases, and other harmful substances into the air, water, and soil. These toxins can enter the human body through inhalation, direct contact, and ingestion of contaminated food.

As plastic continues to break down into smaller microplastics, they can more easily enter the human body and lead to health issues such as inflammation, genotoxicity, oxidative stress, apoptosis, and necrosis. These issues are linked to negative health outcomes, including cardiovascular disease, cancer, inflammatory bowel disease, diabetes, rheumatoid arthritis, chronic inflammation, autoimmune conditions, neurodegenerative diseases, and stroke.

The pervasive presence of plastic in the environment, including in agricultural soils, terrestrial and aquatic food chains, and the water supply, creates further opportunities for human exposure to toxic chemicals.

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