The health damage caused by emissions from the global plastic cycle could double by 2040. According to a modeling study by the London School of Hygiene & Tropical Medicine, London, England, published in The Lancet Planetary Health. Growing primary plastic production is identified as a central driver of this trend.

Building on an existing material flow analysis, the Plastics-to-Ocean model, the study used a life cycle analysis to provide, for the first time globally, a quantitative estimate of lost healthy life years measured as disability-adjusted life years (DALYs) associated with greenhouse gases, air pollutants and specific chemicals emitted across the life cycle of the most common, predominantly single-use plastics.

The researchers examined six future scenarios between 2016 and 2040 — ranging from “business as usual” to ambitious interventions featuring improved waste management, increased recycling and reduced plastic use.

Millions of Healthy Years Lost

The study found that about 2.1 million DALYs worldwide were associated with the plastic life cycle in 2016. In the worst-case scenario, that could rise to about 4.5 million by 2040, and even in the most optimistic scenario, the study estimated about 2.6 million DALYs. According to the authors, the largest health impacts stem from global warming and particulate matter emissions, which each account for roughly one third of the total burden. The study authors emphasized that Primary plastic production is the single most relevant factor.

Direct health effects from microplastics and nanoplastics or from chemicals released during use of plastic products were not included in the modeling due to a lack of reliable data. Sustainability researcher Walter Leal of Hamburg University of Applied Sciences, Hamburg, Germany, said this is a clear limitation of the findings: “Firstly, important effects are omitted: direct health effects resulting from chemical exposure when using plastic products and health effects from microplastics and nanoplastics. These were excluded due to a lack of data. This is a significant underestimation,” Leal told the Science Media Center. However, data on waste management and emissions, especially from low-income countries, are missing, which reduces the model’s accuracy.

True Toll Likely Higher

Environmental medicine specialist Barbara Hoffmann of the Faculty of Medicine at Heinrich Heine University Düsseldorf, Düsseldorf, Germany, also urged caution in interpreting the numbers: “The authors clearly point out that certain elements in the chain from extraction to disposal of plastics are not included because there are not yet sufficient data. As the authors rightly say, these gaps likely lead to a substantial underestimation of the actual disease burden from plastic production, use, and disposal.”

While the contribution of plastic to the health burden of the global population is smaller than other global health risks, it is by no means negligible. Leal said, “The estimated more than four million lost healthy life years in 2040 correspond to about 5 hours of full health lost for every person on Earth.” Compared with other global health burdens, the disease burden from plastics is substantial but much lower than that from general air pollution, which is estimated at more than 100 million healthy life years annually. It is also lower than the burden from malaria, which is estimated at more than 40 million healthy life years lost annually. It is, however, comparable to the burden from hepatitis B and underscores the need to pay attention to this issue.

Despite significant uncertainties, experts see the study as an important basis for policy decisions. It is the first analysis to make visible at a global level the health costs that the entire life cycle of plastics can impose, and it shows that even ambitious countermeasures would not eliminate the burden in the short term.

This story was translated from Univadis Germany, part of the Medscape Professional Network.