A recently published by the U.K.’s Health and Safety Executive (HSE) discusses risks to respiratory health in the grain industry. Researchers conducted a literature search of studies undertaken in Canada, the U.S., and Europe from the 1970s to 2012 to summarize evidence of respiratory disease caused by exposure to grain dust. According to the report, “the most damaging effects of grain dust on the respiratory tract are accumulative and occur at high concentrations.” HSE concludes that long-term exposure to grain dust—which contains plant proteins and chemicals, soil particles, microorganisms and their toxins, small invertebrates, and low levels of farming chemicals—may cause adverse health effects such as chronic obstructive pulmonary disease, allergic airway disease, and impairment of lung function.

HSE’s report also discusses evidence suggesting that workers occasionally exposed to high levels of grain dust who experience a decline in lung function may recover later. Seasonal farm workers involved in grain harvesting are included in this group.

“Seasonal grain workers … experience a reduction in lung capacity during harvesting work, but this decline typically recovers when harvesting work is completed,” the report reads. “The development of chronic phlegm and symptoms of breathlessness during exertion directly relate to the accumulative effects of exposure to grain dust exposures for more than a decade.”

Other topics covered in the report include how cigarette smoke likely accelerates the decline in lung function in workers exposed to grain dust and the relationship between exposure and risks for respiratory disease.