[An epidemiological study of chronic obstructive pulmonary disease in greenhouse farmers in Liaoning Province from 2006 to 2009].

Objective: To investigate the prevalence of chronic obstructive pulmonary disease (COPD) in greenhouse farmers in Liaoning Province from 2006 to 2009.

Methods: By stratified-cluster random sampling, a survey of 5420 greenhouse farmers working in 835 plastic greenhouses was performed using uniform questionnaires in Shenyang, Chaoyang, and Jinzhou during 2006 and 2009. Physical examination and lung function tests were performed for all of the farmer. Blood routine examinations, blood gas analysis, and chest X-ray were performed for some of the subjects with respiratory symptoms and healthy controls. The chi-square test was used for comparison of the 2 sample rates, and the chi-square segmentation method for more.

Results: The overall prevalence of COPD in greenhouse farmers in Liaoning Province was 17.5% (947/5420). Most patients were elderly, especially at the age of 50 years or older. The prevalence of COPD in greenhouse farmers in the plain areas was 15.6% (464/2981), which was lower than that in the mountains (20.2%, 246/1220) and coastal areas (19.4%, 237/1219), with a significant difference (the value of χ(2) were 13.04 and 9.35, all P < 0.0125). The prevalence of COPD in vegetable greenhouse farmers was 12.6% (273/2168), which was lower than that in fungus greenhouse farmers (24.3%, 263/1084), poultry greenhouse farmers (20.8%, 169/813) and flowers greenhouse farmers (17.9%, 242/1355), with a significant difference (the value of χ(2) were 71.49, 31.44 and 18.54, all P < 0.007). The prevalence of COPD was the highest (28.3%, 137/485) in farmers who had worked in the greenhouses for 3 to 5 years.

Conclusions: The overall prevalence of COPD in greenhouse farmers in Liaoning Province was higher than that reported in the rural areas nationally. Attention should be paid to the prevention and control of COPD in greenshouse farmers.