Comparison of Subjective Symptoms and Cold Prevention Measures in Winter between Traffic Control Workers and Construction Workers in Japan

To help making comfortable workplaces and to prevent health disorders induced by the exposure to moderate cold in two different groups of out-door workers, we conducted a survey to compare subjective symptoms and cold prevention measures in winter between traffic control workers and construction workers. The subjects of this study were 98 male traffic control workers and 149 male workers engaged in building construction. Work loads of traffic control workers and construction workers were estimated at RMR1～2 and RMR2～4, respectively. All subjects were asked to complete a self-administered questionnaire covering age, occupational career, working figure, present illness, past history of diseases, individual preventive measures to the cold, subjective symptoms in the winter (43 items) and subjective symptoms occurred during daytime working in the winter (6 items). In two parts of the construction workplaces (the place where a morning assembly was held and on the 7th floor of the construction site) dry bulb, wet bulb and globe temperatures were measured in January. Windchill Index (kcal/cm,2·h) was calculated by the measured dry bulb temperature and wind velocity. Mean values of dry bulb temperature between 9:00 and 16:30 in the place where a morning assembly was held for three days were between 4.8 ± 1.2℃ at 9:00am and 9.3 ± 1.1℃ at noon. Mean values of Windchill Index in the place where a morning assembly was held were between 490.8±23.9 kcal/cm2·h at 9:30am and 608.2±47.3 kcal/cm2·h at 2:30pm. Occupational career, monthly working days, daily working hours, one way commuting hours, and daily smoking numbers of the traffic control workers were significantly shorter than the construction workers (p