Chemical pollution 'has passed safe limit for humanity'

The human race is flooding Earth’s systems with a cocktail of synthetic chemicals - and scientists have warned we have passed a ‘planetary boundary’ with chemicals such as plastics.

The total mass of plastics on the planet is now over twice the mass of all living mammals, and roughly 80% of all plastics ever produced remain in the environment, the researchers warn.

The research, published in the journal Science and Technology, adds to existing thinking on ‘planetary boundaries’ breached by human activity.

“There has been a 50-fold increase in the production of chemicals since 1950. This is projected to triple again by 2050,” says co-author Patricia Villarubia-Gómez from the Stockholm Resilience Centre, Stockholm University.

Plastic production alone increased 79% between 2000 and 2015, the team reports.

“The pace that societies are producing and releasing new chemicals and other novel entities into the environment is not consistent with staying within a safe operating space for humanity,” says Villarubia Gómez.

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In 2009, an international team of researchers identified nine planetary boundaries that outlined the stable state Earth has remained within for 10,000 years - since the dawn of civilisation.

These boundaries include greenhouse gas emissions, the ozone layer, forests, freshwater and biodiversity.

The researchers concluded in 2015 that four boundaries have been breached - but the boundary for new chemicals had remained unquantified, until now.

There are an estimated 350,000 different types of manufactured chemicals on the global market.

These include plastics, pesticides, industrial chemicals, chemicals in consumer products, antibiotics and other pharmaceuticals.

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These are all new, created by human activities with largely unknown effects on the Earth system.

“The rate at which these pollutants are appearing in the environment far exceeds the capacity of governments to assess global and regional risks, let alone control any potential problems,” says co-author Bethanie Carney Almroth from the University of Gothenburg.

The researchers say there are many ways that chemicals and plastics have negative effects on planetary health, from mining, fracking and drilling to extract raw materials to production and waste management.

Carney Almroth says, “Some of these pollutants can be found globally, from the Arctic to Antarctica, and can be extremely persistent. We have overwhelming evidence of negative impacts on Earth systems, including biodiversity and biogeochemical cycles.”

“Plastic production, use and waste affects other planetary boundaries as well. This includes climate, via fossil fuel use, land and fresh water systems via use, pollution, physical changes, and spread of invasive species, antibiotic resistance genes and pathogenic microbes in the oceans.

“Plastics have helped solve some environmental issues owing to their light weight and durability, but overuse and misuse is having devastating impacts on planetary health.”

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The researchers conclude that current increasing trends of chemical production and release put the health of the Earth system at risk. The authors call for actions to reduce the production and release of pollutants.

“We need to be working towards implementing a fixed cap on chemical production and release,” says Carney Almroth.

Villarubia Gómez says, “Shifting to a circular economy is really important. That means changing materials and products so they can be reused not wasted, designing chemicals and products for recycling, and much better screening of chemicals for their safety and sustainability along their whole impact pathway in the Earth system.”

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