Some areas in Taiwan with high population density and many factories are affected by heavy pollution.

But on certain days, usually those with heavy pollution, they had to do it more often.

Because of heavy pollution of the Rhine, both beaches were closed in 1962.

The industry was the cause of heavy pollution which affected the Lys River.

It depended on water power to run its mills, which in turn created heavy pollution, though that now seems to be a thing of the past.

The heavy coastal pollution forced the region's government to suspend offshore fishing for six months.

The river has been subject to heavy pollution during the 20th century.

Summer humidity and the city's heavy pollution make the sky hazy.

Over the years, the cathedral's exterior has become severely worn down due to heavy pollution.

And heavy pollution there has prompted new laws that may help the industry.