By Alex Kirby BBC News website environment correspondent
As part of Planet Under Pressure , a BBC News website series looking at some of the biggest environmental issues facing humanity, Alex Kirby considers the Earth's growing pollution problem.
One of the main themes of Planet Under Pressure is the way many of the Earth's environmental crises reinforce one another.
Pollution is an obvious example - we do not have the option of growing food, or finding enough water, on a squeaky-clean planet, but on one increasingly tarnished and trashed by the way we have used it so far.
Cutting waste and clearing up pollution costs money. Yet time and again it is the quest for wealth that generates much of the mess in the first place.
Living in a way that is less damaging to the Earth is not easy, but it is vital, because pollution is pervasive and often life-threatening.
· Air: The World Health Organization (WHO) says 3 million people are killed worldwide by outdoor air pollution annually from vehicles and industrial emissions, and 1.6 million indoors through using solid fuel. Most are in poor countries.
· Water: Diseases carried in water are responsible for 80% of illnesses and deaths in developing countries, killing a child every eight seconds. Each year 2.1 million people die ...full text