Good vacation and job rotation systems were beneficial for the hemoglobin level of workers at high altitude, a cross-sectional study along the Qinghai Tibet railway, China

Abstract

Working and travelling in high-altitude regions have been associated with a variety of adverse health effects. The aim of this study was to explore a good vacation and job rotation system to prevent workers at high altitude from chronic altitude sickness. A total of 985 healthy male workers along the Qinghai-Tibet Railway, aged from 21 to 58 years (mean age 37.7 ± 8.6 years), were included into this study. The subjects took different short–term vacations, with different ratios of rest and work days. Furthermore, job rotation in low altitude was implemented in 127 (12.9%) subjects, who were transferred to relatively low altitude areas after working in plateau areas for more than three months. The association between vacation type and low altitude job rotation with prevalence of hyperhemoglobin (hemoglobin >175 g/L) was analyzed. Results showed that the risk of hyperhemoglobin decreased significantly with the increase of ratio of rest and work days, after adjusting for other confounding variables (age, ethnicity, education, body mass index, etc.) using multivariable logistic regression analysis. Meanwhile, the prevalence of hyperhemoglobin in job rotated workers was significantly lower than that in non-rotated workers [OR = 0.56, 95% CI: 0.37 to 0.84, p < 0.05]. Besides that, BMI, labor intensity, altitude at the workplace and frequency of oxygen supplementation were also closely related to the increase of hemoglobin level. We concluded that good vacation and job rotation system were effective means to prevent hyperhemoglobin and should be promoted in immigrants at high altitude for a long time.