A field study of cold effects among cold store workers in China.

A field study was carried out among cold store workers in China. A self administrative questionnaire and health check-up were taken among 463 male workers from two different types of cold stores, all during their whole daily work. 296 men from Lower Temperature Stores (LTS), where the air temperature was between -10 to -25 degrees C, and 167 men from Ice Stores (IS), where the air temperature was between -5 and +5 degrees C participated. Another group of 152 men working in normal stores and exposed to an air temperature between 20 and 30 degrees C served as a control group. The study did not indicate any special disease attributable to the cold environment. The number of complaints of lower back pain and knee pain in the cold exposed group were significantly higher than that of the control group (in LTS: 42.3%, 46.6%; IS: 52.7%, 50.8%; control group: 9.2%, 14.5%; low back and knee pain, respectively). After 5 years of cold exposure work, the lower back and knee symptoms were very frequent. The point press pain on the knees of the cooler group (LTS) was higher than in the moderate cold group (IS). We suppose that the cold factor contributed to lower back and knee pain. 12.2% of 463 cold exposed workers had frostbite on the body extremities viz: hand, foot and ear. Self estimation of health indicated more problems among cold exposed workers (28.0%) than control group (2.7%).