Almost half the world cooking as if it were the stone age, WHO warns

Smoke from cookstoves among range of environmental factors driving rise in costly non-communicable diseases in poor countries, says Dr Maria Neira

The good news is that more people have mosquito nets, and better access to clean water and toilets. The bad news, says Dr Maria Neira, head of public health and the environment for the World Health Organisation (WHO), is that populations have grown fast and little progress has been made in the past 10 years to prevent illness in developing countries.

"Yes, we are spending more on treating TB, malaria and diarrhoea than we were 10 years ago. But we are not spending anything like enough on building good sanitation and water systems. Only 3% of our health spending goes to stop people becoming sick; 97% is spent when people are sick."