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The 10 worst forms of pollution

Pharmaceutical pollution

Photo: Mahesh Kumar/Associated Press

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Pharmaceutical pollution

Pharmaceutical waste is becoming one of the world's biggest pollution concerns. Millions of doses of drugs are prescribed to people annually, and even more antibiotics are given to livestock. Those chemicals eventually make their way into the water supply. There is a natural risk to human health, but the bigger fear is that the pollution will ease the evolution of superbugs — bacteria that are immune to antibiotics.