Plastics are making us sicker — Global health impact may double by 2040

The study finds that plastics harm human health at every stage of their life cycle — from the extraction of fossil fuels, which provide feedstocks for more than 90% of plastics, through manufacturing and use, to disposal or release into the environment.

Led by researchers from the London School of Hygiene & Tropical Medicine (LSHTM) in collaboration with the University of Toulouse and the University of Exeter, the study used modelling to compare health impacts under different future scenarios of plastics production, consumption and waste management between 2016 and 2040.

Under a business-as-usual scenario, the researchers estimate that negative health impacts from plastics could double by 2040. Greenhouse gas emissions and rising global temperatures would account for around 40% of the harm, while air pollution — largely from plastics production — would contribute 32%, and toxic chemical releases across the plastics life cycle 27%. The remaining impacts, less than 1%, relate to reduced water availability, ozone depletion and increased ionising radiation.

The findings have been published in The Lancet Planetary Health.

The study is the first to estimate, at a global scale, the number of healthy years of life lost, measured in disability-adjusted life years (DALYs), due to greenhouse gases, air pollutants and toxic chemicals emitted throughout the plastics life cycle. These emissions are linked to a range of health problems, including global warming-related illnesses, respiratory diseases and cancers.

The modelling shows that if current policies, economic structures, infrastructure, materials and consumer behaviours remain unchanged, annual health impacts could rise from 2.1 million DALYs in 2016 to 4.5 million DALYs by 2040. Overall, the global plastics system could be responsible for the loss of 83 million years of healthy life between 2016 and 2040.

Researchers also examined alternative scenarios involving varying levels of intervention. Measures such as improving waste collection or increasing recycling alone were found to have limited impact on reducing global health burdens. However, a full system transformation — combining multiple interventions — could reduce plastics-related health harms by 43% in 2040 compared with the business-as-usual scenario.

Across all scenarios, emissions from primary plastics production emerged as the leading cause of health impacts. The study concludes that reducing plastics production, without substituting plastics with other harmful materials, would deliver the greatest health benefits. While transitioning to renewable energy could help reduce climate and air pollution impacts, it would not address other hazardous outputs from plastics production and waste management.

Megan Deeney, study author and Research Fellow at LSHTM, said the health effects of plastics extend far beyond consumer use.

“Our research shows that the adverse health impacts of plastics stretch far beyond the point at which we buy a plastic product or put plastic items in a recycling bin,” she said.

“While individuals have a role to play, our analysis shows that systemic change is needed — from the ‘cradle to the grave’ of plastic production, use and disposal. Much more ambitious action from governments and greater industry transparency are essential to curb this growing global public health crisis.”

She added that limited disclosure by industry on plastics’ chemical composition is severely constraining effective policymaking and scientific assessment.

Co-author Professor Xiaoyu Yan of the University of Exeter said the study demonstrates how modelling tools typically used for environmental footprint analysis can be applied at a global scale.

“Our findings reveal the massive impacts of plastics on human health across their life cycle and highlight the urgent need for action to reduce these harms,” he said.

The authors caution that the study is based on modelling and available emissions data, which have limitations. For example, the analysis could not include health impacts associated with the use phase of plastics or exposure to many chemicals, microplastics and nanoplastics, due to data gaps and a lack of transparency from producers.

They stress that mandatory, harmonised global reporting and data-sharing mechanisms are crucial to improving research and informing policy. “The current trajectory is not tenable,” the authors conclude, adding that large-scale reductions in plastics production and the elimination of hazardous chemicals are needed to protect both human health and the environment.