Nearly a quarter of global diseases are caused by exposure to avoidable environmental hazards, the World Health Organization (WHO) said in a report on Friday.

Environmental exposures cause as much as 24 percent of all diseases, and more than 33 percent in children under the age of five, said the report, titled "Preventing disease through healthy environments -- towards an estimate of the environmental burden of disease."

Well-targeted interventions could prevent much of this environmental risk, saving as many as four million lives a year, mostly in developing countries, the report added.

WHO said the new report was the most comprehensive and systematic study yet undertaken on how preventable environmental hazards contribute to a wide range of diseases and injuries.

By focusing on the environmental causes of diseases, and how various ones are influenced by environmental factors, the analysis breaks new ground in understanding the interactions between environment and health, the Geneva-based organization said.

The report estimated that more than 13 million deaths annually are due to preventable environmental causes. Nearly one third of deaths and diseases in the least developed regions is due to environmental causes.

More than 40 percent of deaths from malaria and an estimated 94 percent of deaths from diarrhoea could be prevented through better environmental management, the report said.

The four main diseases influenced by poor environments are diarrhoea, lower respiratory infections, various forms of accidental injuries, and malaria.

Measures which could be taken now to reduce this environmental disease burden include the promotion of safe household water storage and better hygienic conditions; the use of cleaner and safer fuels; increased safety on building sites; more judicious use and management of toxic substances in the home and workplace; and better water resource management.

The research, which involved a systematic review of literature as well as surveys of more than 100 experts worldwide, identifies specific diseases caused by certain well-known environmental hazards.

"For the first time, this new report shows how specific diseases and injuries are influenced by environmental risks and by how much," said Dr Maria Neira, director of WHO's Department for Public Health and Environment.

Source: Xinhua