Objective To measure the physical work intensity of electrical maintenance workers working in plateau, and evaluate the heart rate and arterial oxygen saturation (SaO2) in workers performing varied physical work intensities.
Methods Thirty-eight workers currently performing electrical maintenance tasks in plateaus with different altitudes were recruited, including transformer station maintenance workers and field wire maintenance workers. Physical work intensity indices, SaO2 , and heart rates in workers with different types of work and types of action were measured and caculated respectively.
Results The intensity indices of physical work of transformer station workers at 3 600 m altitude and at 4 200 m altitude and of field wire maintenance workers were 14.1, 12.4, and 23.6 respectively. Mountain hiking and steel tower climbing were the two types of action with extraordinary high energy metabolic rates of 3.48 and 3.22 kJ/(min& #183;m2) respectively. The SaO2 and heart rate at 3 600-3 900 m altitude were similar to those at 4 200 m in state of rest. In state of working, the SaO2 and heart rates were within the national occupational health limits. Instead, one wire maintenance worker reported SaO2 lower than 85%, and three others' heart rates were more than 150 beats/min.
Conclusion The physical work intensities of transformer station maintenance workers and field wire maintenance workers in plateaus are classified as Ⅰ and Ⅲ respectively. Specifically, mountain hiking and steel tower climbing have the leading two values in intensity index, which cause heart rate and SaO2 exceeding relevant national standards.
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