Pollution and the diseases it often causes are responsible for the deaths of 1.7 million children around the world every year, according to the UN World Health Organization (WHO).

"A polluted environment is a deadly one - particularly for young children," WHO Director-General Margaret Chan said.  "Their developing organs and immune systems, and smaller bodies and airways, make them especially vulnerable to dirty air and water."

The report by the United Nations public health arm is titled "Inheriting a sustainable world: Atlas on children's health and the environment".  It says that unsanitary and polluted environments such as contaminated water lead to fatal cases of diarrhea, malaria, and pneumonia.  These weaken the immune systems make children's health more vulnerable to harmful effects of polluted environments.

Exposure to pollution, both indoor and outdoor, can increase the chances of premature birth.  Infants and preschool children exposed to contaminants are at a higher risk of contracting pneumonia and chronic respiratory diseases.  From there, the likelihood of cancer, cardiovascular diseases, and even and stroke are also increased.

The report also notes that around 25 percent of all global deaths of children under five were due to unhealthy or polluted environments, and more than 90 percent of the world's population is thought to breathe air that violates quality guidelines set by WHO.