Ahead of world’s first plastics treaty, why Lancet project to monitor health impact matters

An international group of researchers and experts has launched an initiative aimed at tracking health impacts due to plastics, ahead of the final negotiations before the signing of the world's first treaty on regulating the chemical substances.

Titled 'The Lancet Countdown on Health and Plastics', the launch accompanies the release of a 'Health Policy', which has been published in The Lancet journal, and a review of currently available evidence on how plastics — including microplastics and plastic chemicals — affect human health.

The team of experts, including members of the United Nations (UN)-established Intergovernmental Negotiating Committee, have authored the 'Health Policy' document.

The UN Global Plastics Treaty is a legally binding document aimed to regulate plastics through their life cycle from production to consumption to disposal.

The second part of the fifth session of the Intergovernmental Negotiating Committee — titled 'INC 5.2' — is scheduled for 5–14 August 2025, in Geneva, Switzerland. The first part took place in Busan, South Korea, in November–December 2024.

In the Lancet document, the team of experts point to projections of plastic production, which is expected to triple by 2060, should the current trends continue.

Lead author Dr Philip Landrigan, a paediatrician and epidemiologist, director of the global observatory on planetary health at Boston College, US, said a great deal is known about the range and severity of the health and environmental impacts of pollution across plastic's life cycle, with most falling heavily on the vulnerable, especially infants and children.

"To those meeting in Geneva: please take up the challenge and the opportunity of finding the common ground that will enable meaningful and effective international cooperation in response to this global crisis," Landrigan said.

Describing the evidence of how an exposure to plastics at any stage of its life cycle — production, use or disposal — can endanger one's health, the experts said emissions during production add PM2.5 particles to the air, thereby contributing to pollution.

Sulphur dioxide and nitrogen oxide, along with hazardous chemicals, are also released, to which workers are exposed, the experts added.

The team also pointed to a lack of transparent communication regarding the constituents and toxicity of plastics.

Studies have found microplastics in tissues obtained from humans' brains and reproductive organs, among other body parts, indicating the pervasive nature of the materials.

Microplastics have been consistently associated with higher cardiovascular and neurological risks, even as evidence in this regard continues to emerge.

The experts said that while more research is needed to understand the relationship of plastics with potential health impacts, "a precautionary approach is warranted".

They added that nearly 60 per cent of unmanaged, untreated plastic waste is estimated to be burned in the open and is a major source of air pollution in low- and middle-income countries.

The review also found evidence of how plastic waste can provide an environment for mosquitoes to lay eggs and enable growth of micro-organisms, which go on to spread vector-borne diseases and antimicrobial resistance.

Antimicrobial or antibiotic resistance occurs when disease-causing microbes have become immune to the very drugs designed to kill them, thereby rendering the drugs ineffective in treating a disease.

It is said to contribute towards prolonging the duration of a patient's hospital admission, raising treatment costs and burdening healthcare systems, especially in places where resources are already stressed.

The newly launched Lancet Countdown "will identify and track a series of indicators that document the impacts of plastics and plastic chemicals on human health across all stages of the plastic life cycle", with the first report expected in mid-2026, the authors said.

Co-author Margaret Spring, co-lead of a working group under the Lancet Countdown on Health and Plastics, said, "The Countdown reports will offer a robust, independent, and accessible data source that can help to inform development of effective policies addressing plastic pollution at the international, regional, national, sub-national and local levels."

The best available scientific evidence will need to be accessed for developing and implementing the important (plastics) treaty in the months and years to come, Spring added.