Plastic is everywhere. Inside the human body, in the depths of the ocean and the far reaches of the Arctic. Now a new study warns that, unless the world changes course, plastic could more than double its damage to human health within the next two decades.
The culprit is not plastic litter in the environment or microplastics, but the emissions released across plastic's entire life cycle — from fossil fuel extraction and manufacturing to transport, recycling and disposal.
Plastics — 99% of which are manufactured from fossil fuels — have become nearly unavoidable. The material is used in everything from packaging, furniture and clothing to construction materials, medical devices, and tires.
Overall, the study published in The Lancet Planetary Health estimates such emissions could slash 83 million years of healthy population life between 2016 and 2040.
Plastic: A convenient but highly polluting material
The new study says it is the first to estimate the number of healthy years of life lost due to the life cycle of plastics. That includes greenhouse gases from oil and gas extraction, fine particulate matter released during production and transport, and toxic chemicals emitted during manufacturing, recycling or waste disposal.
These pollutants harm health directly — for example, by contributing to respiratory and cardiovascular disease — and indirectly, by contributing to climate change and its health impacts.
In the US state of Louisiana, a stretch of more than 200 petrochemical plants involved in plastic production has been dubbed "Cancer Alley," with recent research suggesting the cancer risk in the area is 11 times higher than government estimates. Yet production there and elsewhere is ramping up.
According to projections by the OECD, global plastic consumption could nearly triple by 2060. As production increases, so do emissions — and so does the health burden.
To understand what this could mean in practice, the study modeled six future scenarios, reflecting different ways humanity might manage plastic and projected the health impacts in 2040.
Counting years of lost healthy life
To measure the effects, the team used "disability-adjusted life years," or DALYs — a standard public health metric. One DALY represents one year of healthy life lost, either due to premature death or diminished quality of life from illness.
First, the researchers estimated how much plastic would exist globally under each scenario. They then calculated how many healthy life years would likely be lost because of the emissions associated with those amounts of plastic.
Their baseline year was 2016. Based on the amount of plastic in use at the time, they estimate that around 2.1 million healthy life years were lost globally in that year.
In the "business as usual" scenario — where plastic production, recycling rates and waste leakage remain broadly unchanged — health damages skyrocket. In 2040, annual losses would exceed 4.5 million healthy life years, more than double the 2016 figure.
Even under the most optimistic scenario, plastic would continue to take a significant toll. Despite reduced plastic use, higher recycling rates and better waste management, an estimated 2.6 million healthy life years would still be lost in 2040 — about half a million more than in 2016.
The climate toll of plastics
"The more than 4 million lost healthy life years estimated for 2040 correspond to roughly five hours of lost full health for every person on Earth," said sustainability researcher Walter Leal of Hamburg University of Applied Sciences in Germany, who was not involved in the study.
Across its life cycle, plastic accounts for about 4.5% of global human-caused greenhouse gas emissions, Leal added. That is less than emissions from energy production or agriculture. The overall health burden is also lower than that caused by general air pollution.
"But plastic is still a major source of air-polluting particles," he said. "And given the rapid growth in plastic production, this is a problem that demands urgent political action."
Only the 'tip of the iceberg'
The study does not include several potentially serious health risks, because reliable global data are still lacking.
The researchers did not factor in possible effects of micro- and nanoplastics on health, for example. Nor did they include harms caused by toxic chemicals that may leach from plastic products during everyday use.
That means the real health costs of plastic pollution are almost certainly higher and their estimates are likely "just the tip of the iceberg," study coauthor Megan Deeney told DW.
"There is good evidence to be deeply concerned about the global harms to human health across plastics life cycles," said Deeney, a research fellow at the London School of Hygiene and Tropical Medicine. "We have enough evidence to know that we need to take urgent action."
Plastic production continues to rise despite growing evidence of harm, added Deeney, while plastic pollution is increasing rapidly worldwide.
Other studies have shown that plastic pollution intensifies a range of environmental pressures, with direct consequences for human health.
Why reducing plastic production matters
The most effective way to reduce plastic-related health damage, the authors said, is to produce less new plastic. That does not mean replacing plastic one-for-one with other materials, which can create new environmental problems.
Deeney suggested countries should reduce consumption, eliminate unnecessary products, and switch to reuse systems. Plastics should be used only where no viable alternatives exist, with hazardous chemicals banned in their production, she added.
Ideally, measures and exchange of information "would be internationally harmonized under a strong, legally binding global plastics treaty that addresses the full life cycle of plastics and chemicals of concern in plastics."
UN talks on an international plastics treaty collapsed last year, after major oil-producing states blocked measures to limit new production, despite broad agreement that plastic waste is a global problem.
Still, Deeney said, "there is much that can be done to address plastics pollution by individuals, organizations and local and national governments."
This article originally appeared in German and was adapted into English by Jennifer Collins.
