Back in the 1960s, our environmental problems were piling up and becoming visible. Scientists investigating mass mortality in birds pinpointed mercury poisoning as the cause. Along with other chemicals, mercury use in agriculture had soared since the 1940s as food production became more intensive and industrialized.
As a result, magnificent birds of prey like the white-tailed eagle – Europe’s largest raptor – came within a whisker of extinction. As top predators they were vulnerable to toxins – especially DDT, which when ingested from prey made their eggshells so thin that they cracked before hatching. The conclusion was that mercury and other chemicals such as DDT and PCB were toxic pollutants that could “biomagnify” (become increasingly concentrated) in food chains and end up in humans.
In the 1960s, fish floated dead on lake surfaces due to acid rain. Newspapers ran stories about “forest death”. And the seal population on Sweden’s west coast halved. People started demonstrating. They were worried – because toxins, it seemed, were everywhere.