The first programme reports from Nepal, its opening scene that of the acute respiratory disease ward in Kathmandu’s Children’s Hospital, where the patients all come from isolated rural villages. It ends in the high mountain village of Gatlang, within view of Tibet, to show the impact of a programme that’s introducing low-cost smoke-hoods. But for many families the $15 cost is too great.

The second programme reports firstly from the Western Highlands of Guatemala, where a group of Mam (Mayan) villages have become the site for the only systematic randomised controlled trial into the health impact of indoor air pollution. Its leader, Kirk Smith from Berkeley, must be one of the unsung heroes of environmental medicine ; his testimony underlines how difficult it is to raise funds for research that will not end up with a pharmaceutical product ! His trial focuses on the link between smoke-filled domestic environments and the incidence of childhood pneumonia. The results are hugely significant. The programme then shifts back to Nepal, to the long-established and largely forgotten Bhutanese refugee camps in the south-east of the country. Here I could illustrate a tragedy that is being repeated all too frequently in such places as Darfur – the relationship between the dependence of displaced communities on firewood and the regular rape of women and girls who spend their days collecting it.

The people who die unnecessarily from indoor air pollution are those with the least powerful voices in the world. I’m glad to have been able to give them a voice – especially in the strange and beautiful languages of the Tamang and the Mam.