Final answer:
Europe's biggest pollution problem is acid rain, which is caused by the release of sulfur and nitrogen oxides in industrial areas.
Step-by-step explanation:
Europe's biggest pollution problem is acid rain. In industrial areas, the release of sulfur and nitrogen oxides into the air without being stripped causes acid rain. It was responsible for the destruction of forests and freshwater lakes in North America and Europe until the 1980s. Acid rain is also a growing problem in industrial areas of China and India.