Cleaners, farmers and hairdressers are more likely to suffer from asthma than other workers because of their jobs, scientists believe.
They found the workplace could be to blame for around one in six cases of the condition among adults.
Those regularly exposed to cleaning or disinfectant products, flour, metal and metal fumes were most at risk of developing asthma, they said.
The authors examined the records of thousands of adults whose health was tracked from birth in 1958.
Information relating to the symptoms of asthma or wheezy bronchitis was collected at the ages of seven, 11, 16, 33 and 42.
The group was tested for sensitivity to allergens. Scientists also examined their lung power between the ages of 42 and 45 and questioned participants on their work history.
Their analysis showed the start of asthma in adulthood was clearly linked to 18 types of job, including farming, which more than quadrupled the risk of developing the condition, and hairdressing, which almost doubled the risk.
Cleaners were up to twice as likely to develop breathing problems.
Meanwhile, those exposed to high-risk agents -- flour, enzymes, cleaning or disinfectant products, metal and metal fumes, and textile production -- were 53pc more likely to suffer from asthma. Cleaning products have previously been identified as a potential cause of asthma.
The scientists, led by Rebecca Ghosh, of Imperial College London, said: "We observed consistently higher risks associated with working as a cleaner, in jobs likely to include cleaning tasks, and in jobs likely to lead to exposure to cleaning and disinfecting products."