Subjective symptoms of female workers sorting goods in summer

Subjective musculoskeletal symptoms are more frequently complained about in cold store work and in related conditions than those experienced in normal temperature work. This cross sectional study was undertaken to evaluate the effects of indoor cooling and cold storage goods on the prevalence of subjective symptoms in summer. Female workers sorting cold storage goods (exposed group) were the main subjects of this study (n=47). We also included a group of female workers engaged sorting dry goods as the unexposed to cold group (n=86). Work load for the two groups were estimated according to the recommended criteria. A self-administered questionnaire covering age, occupational career, smoking, alcohol drinking and physical exercise, present or past history of diseases, individual protective measures against cold or heat, and subjective symptoms (60 items) was used. The air temperature of the site at the start of working time for the workers sorting cold storage goods was 22.2℃ which was significantly lower than those measured for the other two work places (25.4℃ and 25.4℃) of the unexposed to cold group. Environmental temperatures at the foot level at the sorting workshop of cold storage goods and dry goods were ca.16℃ and 26℃ all day, respectively. The surface temperatures of cold storage goods were between -2.8℃ and 9.4℃. The surface temperature of dry goods was 26.5℃. Among the working characteristic items, only daily working hours in the exposed group (5.6 ± 0.6 h) were significantly longer than those in the unexposed to cold group (4.6 ± 0.9 h) (p<0.01). The prevalence rates of finger cold sensation, stiffness in the fingers, pain in the wrist, pain in the elbow, back dullness, back pain, low-back cold sensation, foot cold sensation and pain in the foot in the exposed group were significantly higher than those in the unexposed to cold group (p<0.05 or p<0.01). Pain in the fingers, numbness in the fingers, pain in the foot and foot numbness due to the cold in the exposed group were significantly higher than those in the unexposed to cold group (p<0.05 or p<0.01). These results suggest that indoor cooling and/or job activities related to cold storage goods could, to some extent, affect peripheral circulatory disturbances; and it could be regarded as a factor related to musculoskeletal symptoms among the exposed workers.