1. What is the leading worldwide cause of deaths and diseases?

Water pollution is the leading worldwide cause of deaths and diseases.
2. How many people die every day by water pollution?

More than 14,000 people die every day by water pollution.
3. How many percent of the water in the cities of China is polluted?

25% of the water in the cities of China is polluted.
5. What phenomena cause major changes in water quality and the ecological status
of water?

Volcanoes, algae blooms, storms, and earthquakes.