Seafarers and cleaners are most likely to develop COPD, a type of lung disease, according to the unexpected results of a UK study.

Cleaners, roofers, tilers and postmen have among the riskiest jobs for developing lung disease, British research suggests.

A new study found seafarers who work on ships, boats and barges have the highest risk of contracting Chronic Obstructive Pulmonary Disease (COPD), a lung condition that can make it difficult to breathe.

They were followed by coal miners, industrial cleaning workers, roofers, tilers and slaters, and people working in factories, such as packers, bottlers, canners or fillers.

Also at risk were people working in food or tobacco processing, domestic cleaners, floorers and postal workers or couriers.

The research based on information from more than 228,000 people was presented at the British Thoracic Society meeting in London.

The researchers, from Imperial College London, suggested that exposure to particulates in diesel motor exhausts and other fuels on board vessels may account for the high risk among seafarers.

Data for everyone in the study was obtained using records of spirometry testing (a breathing test which measures lung function) and then matched with people's occupation.

"This study has shed more light on the specific occupations associated with an increased risk of COPD in the UK general population," said Dr Sara De Matteis, who led the study.

"Some of them were already known, such as coal miners, but others are new findings such as seafarers or cleaners.

"The main strength of this study is the unprecedented scale that allowed us to explore not only a broad range of occupations in the general population, but also to confirm the validity of our results among those in our sample who never smoked which meant that we were able to rule out any confounding effect from tobacco smoking.

"Exposure to occupational hazards is both avoidable and involuntary; therefore it is essential to identify the occupations at higher risk of COPD in order to try and then eliminate or at least reduce the burden of work-related lung disease."