One of the planetary boundaries already exceeded concerns chemical pollution, meaning the release of new synthetic chemicals into the environment without adequate safety testing. There are currently hundreds of thousands of chemicals in use, and for many of them, the long-term impacts on the environment and humans are unknown. Large-scale and uncontrolled chemical contamination and exposure may harm nature and human health. 

What if harmful substances were to spread across a wide area? What if the harmfulness of a particular substance was only discovered with a delay, once it was already widespread? How would this affect food production, healthcare or relations between countries?