Emulsified oil washes ashore after the MV Braer, a U.S.-owned oil tanker, ran aground in hurricane-force winds off the Shetland Islands. The 1993 spill emptied 93,366 short tons (84,700 metric tons) of oil into the North Sea.
Test your knowledge of pollution with a dozen dirty questions.
Pollution can affect everything from the water we drink to the air we breathe. Test how much you know about the contaminants in the environment with this quiz.