More than one in ten Nepalese now suffer a chronic lung problem like emphysema or bronchitis, as a result of worsening air pollution in the country.

The findings are the result of a study by the Nepal Health Research Council into air quality in the country, which has been labelled the "worst in the world".

Air pollution has become so acute in Nepal that a baby born today can expect to have a two-year shorter life expectancy due solely to problems brought on by the air they breathe.

The study was based on a sample of 13,200 people, evenly spread across 400 clusters in the country. From each geographical cluster, 33 households were selected. All of those surveyed were over the age of 20.

The research found the issue is country-wide, with both urban and rural populations affected – but for different reasons.

Rapid urbanisation, the increase in the number of roads in cities and consumer buying power has led to 3.22 million more vehicles on the Nepalese roads since 1990.