Global chemical pollution now exceeds safe limit for humanity: study

A new study warns that the amount of chemical pollution on the planet has now exceeded a safe limit, threatening the 'viability' of human civilization.

An international team of researchers published their findings in the journal Environmental Science & Technology on Tuesday. Their study builds on a 2009 Swedish-led paper that established the safe limit, otherwise known as "planetary boundary," for several environmental metrics, including greenhouse gas emissions, ozone layer depletion, deforestation, biodiversity loss, ocean acidification, and chemical pollution.

The planet had remained within those limits for 10,000 years since the start of human civilization. But a 2015 study concluded that we had then exceeded safe limits when it comes to climate change, biodiversity loss, shifts in soil nutrients and land use. Now, this new study says we're beyond the planetary boundary for chemical pollution, also called "novel entities."

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"The impact of those changes is on the viability of human civilization," study co-author Miriam Diamond, a University of Toronto environmental sciences professor, told CTVNews.ca over the phone on Friday. "We are very concerned that there's a tipping point at which human civilization is really imperilled."

There are around 350,000 different chemicals manufactured globally. These chemicals are involved in everything from plastics, pesticides, manufacturing, industrial applications, pharmaceuticals and more.

"That means everything from what's in my toothpaste to what I'm wearing," Diamond said. "We mobilize many, many chemicals in our daily lives, of which we're able to understand the implications of so few."

These chemicals are ubiquitous. They can be found on all seven continents, in the atmosphere and even in Mariana Trench – the deepest part of all the oceans.

'CANADA NEEDS TO BE A LEADER'

Chemical production has seen a 50-fold increase around the world since 1950 and researchers expect that to triple by 2050. Plastic pollution alone increased 79 per cent between 2000 and 2015 and is expected to reach 33 billion tonnes by 2050.

"The rate of production and the rate at which new chemicals are entering commerce far exceeds the rate at which we can figure out their effects," said Diamond.

Some of the adverse effects of these chemicals can be clearly seen in certain animal populations. For example, polychlorinated biphenyl, an industrial chemical that was banned in North America in the 1970s, continues to linger in our ecosystems and has been linked to reduced fertility in orca whales and polar bears, threatening their populations. Seabirds have also been observed ingesting plastic while mistaking it for food, which often leads to death.

"You can find a synthetic chemical in every organism on the planet," Diamond said.

In humans, numerous studies have found a correlation between exposure to certain chemicals and reduced fertility, lower IQ and even weaker immune functions.

"It's a big, large body of evidence. It's not a single study. It's many studies, from the toxicological studies done in test tubes, to the rats and mice and to the epidemiological studies in humans," said Diamond.

At the COP26 climate summit in Glasgow last November, Prime Minister Justin Trudeau announced plans to impose a hard cap on oil and gas emissions. Diamond believes similar measures should be taken to limit the production of chemical pollutants.

"Canada is so far behind. You know, this is bad news for Canadians, because ultimately … reducing our dependence on so many synthetic chemicals is going to benefit our prosperity because it will push innovation," she said. "Canada needs to be a leader."