Plastic pollution: why is it a public health problem and why Australia needs a plastic pollution policy

Dr Andrew Daltry, Dr Lea Merone, Dr Peter Tait, and Jeremy Lasek

It was described as a ‘global pandemic’ long before COVID-19 rocked our world in early 2020.

The so-called ‘plastic pandemic’ sees an estimated five trillion pieces of plastic in the world’s oceans right now and it can take decades, or even centuries to break down. Consider this; experts think that by 2050, the amount of plastic in the ocean will weigh more than the amount of fish in the ocean.

No one doubts the usefulness of plastics. Since their commercial development in the 1930s and 1940s, the modern world has become hugely reliant on plastics. They have extensively replaced wood, metal, ceramics and glass in manufacture and construction. They are embedded in the economic system and our daily lives. But at what cost?

Each year, an estimated 100,000 animals in the sea are killed by plastic. While much has been written on the devastating impact of plastics on marine and bird life, there’s been much less reported on the human toll.

A new report in the Australian and New Zealand Journal of Public Health (ANZJPH) ‘Plastic pollution: why is it a public health problem?’  reviews both the size of the problem and its growing impact on human health.

The stats published in the report can only be described as frightening. The following is an edited version of the full report.

Understanding the size of the problem

Global plastic resin production has increased 620% since 1975 and much of this increase is used for packaging of other items. Plastics have been considered disposable, and consequentially plastic waste has grown.

In 2012, there were 280 million tons of plastic produced across the globe, and less than half of this was disposed of in landfill or recycled.  While some may still be in use, a large portion of the remainder becomes waste in the environment, with a substantial portion entering the ocean. The International Union for Conservation of Nature says eight million tons of plastic accumulate in the ocean annually.

Plastics do not generally biodegrade and thus are a growing environmental, political and public concern.  Most plastics in the environment ultimately end up in oceans via storm drains, rivers, sewage disposal and flooding. Once in the ocean, they float and converge into ‘islands’ or sink to the seabed. While 10% of all waste is plastic, around 80% of waste that accumulates in the oceans and seabed is plastic. Videos of ‘plastic islands’ in the oceans and flowing ‘rivers of plastic’ flood the media, and yet despite public outcry, seemingly little is being done about this crisis.

The public health implications of plastics and plastic pollution

While once considered inert, unreacted monomers and other harmful substances can be found within plastics. Some plastics may be chemically harmful, either directly toxic themselves or because they absorb and carry other pollutants. Chemical effects include damage to the heart, nervous system, reproductive system and potential cancers.

Seafood, alcohol and plastic-bottled water are the greatest sources of microplastic ingestion in humans. While the investigation of the toxic effects of microplastics in food webs is complex and ongoing, evidence suggests that ingestion of these microplastics in humans may be associated with infertility, obesity and suspected endocrine dysfunction including oestrogen mimicking, which in women has been associated with breast cancer. While difficulty lies in separating the comparative exposure from pollution and food webs and exposure via food packaging, it could be argued that this separation is a moot point should significant human health effects begin to unfold.

While there is very limited information about the long-term human health effects of plastics, research has demonstrated high levels of bisphenol (BPA) in women and young infants and this may cause alterations in neurological white matter in children. These findings require more long-term research. BPA is both a plastic monomer component and an additive to many varieties of plastic.

Ingestion is the commonest route of exposure via plastic packaging, particularly re-usable plastic packaging, where repeated washing and storage results in polymer breakdown. Studies have determined that around 95% of humans have detectable serum and urinary levels of BPA. The overall health risks of BPA are still under debate and are by no means fully comprehended.

Plastics prevention

We need to both remove existing and prevent new contamination. Prevention is partially addressed by the slogan: reduce, refuse, reuse, repurpose and recycle. This focuses on what individuals can do to divert pollution from the environment The more complex issue of our societies’ reliance on plastic needs discussion, policy development and decisions about production, use and waste management.

While the risks and impacts of plastic-related toxin exposure need further investigation, more extensive and integrated safe recycling and disposal of plastics must increase significantly on a global scale to prevent potential harms.

We support Australia’s National Waste Policy target to phase out problematic and unnecessary (read single use) plastics by 2025 and the action several jurisdictions are making toward this. In addition, we suggest that the National Waste Action Plan be strengthened in relation to the reduction in use of plastics by industry, stronger government leadership and where plastics can’t be avoided, a move away from fossil fuel generated plastics to bio-plastics.

What individuals can do immediately, while insufficient, is useful; in 2016–17 in Australia, a mere 12% of generated plastics were recycled. This low yield is often due to poor public understanding regarding the suitability of different plastics for recycling.  Consequentially, within a broad policy response, advocacy and education are fundamental to addressing plastic pollution.

Individual action can occur at the personal, household and community level. Community-based social marketing is an approach that provides evidenced-based strategies that governments, usually local, can use to lead such action on waste reduction and recycling.

To promote awareness and normalise sustainable waste management practices, social initiatives such as ‘Plastic-free July’ encourage people to reduce their single-use plastic purchases and find novel ways to reduce plastic pollution. Additionally, local governments and agencies hold public events to assist with marine clean-ups. Such initiatives build on public education and advocacy, fostering a sense of individual responsibility for plastic pollution reduction.

Clean-up of the plastics already in the environment is a mammoth task that, while beginning with such projects as ‘The Ocean Clean-up’, can never be completed while production and improper disposal continue. In addition, after collection, the waste still needs further disposal. An alternative to recycling and incineration is using microbes to degrade plastics enzymatically.

Urgent action needed now

This is a serious environmental crisis that has both direct and indirect adverse effects on the public’s health. The public health profession’s role is education and advocacy through policy development, and campaigning for governments, industry and individuals to take the necessary preventive and protective actions. Further, we need to adopt the concept of ecosystem stewardship that is emerging within the eco-social and planetary health domains.

This is an action-based framework for the development of ecological sustainability, including reducing the vulnerability of communities to expected changes, fostering resilience and responding to trajectories where possible.

It is imperative that management strategies are developed and implemented now, for if plastic pollution rates continue as they are, it is likely there will be 33 billion tons of plastic present globally by 2050.

Inaction is arguably an action in and of itself and one that could be catastrophic for the health of the planet and all its inhabitants. Natural disasters or calamities cannot be avoided, but man-made blunders can be stopped or terminated.

The ANZJPH article Plastic pollution: why is it a public health problem? Was co-authored by Andrew Daltry, Lea Merone and Peter Tait.

Image: ‘This Fish Eats Plastic Daniel Capilla / Wikimedia