Dioxin
From Tardis Wiki, the free Doctor Who reference
Due to human activity, Earth had a lot of dioxins and toxins in its atmosphere, which would have provided decent nutrition for the Nestene Consciousness. (TV: Rose)
In the early 21st century, rain water had tiny but measurable amounts of cadmium, dioxin, lead and plutonium due to high pollution levels. (PROSE: Cat's Cradle: Warhead)
