Asbestos is widely used in all walks of life,but the hazard of asbestos to human is currently a major public health problem all over the world,especially carcinogenicity. Asbestos can cause lung cancer, mesothelioma,throat cancer,digestive system cancer,ovarian cancer and other diseases. In recent years,epi-demiological data and experimental results have confirmed the carcinogenicity of asbestos from multiple perspec-tives.

Objective To understand the characteristics of long-working hours exposure of medical staff,and analyze the impact of long-working hours exposure on mental health problems such as occupational stress,depression,fatigue accumulation,and insomnia.Methods The cluster random sampling method was used to select the medical staff of 12 tertiary general hospitals in Guangdong Province as the research subjects,and the"Core Scale of Occupational Stress Measurement"and other scales were used to evaluate their occupational mental health.Results The average working hours of medical staff per day were(8.99±2.18)h;2,094 people were exposed during long working hours,accounting for 78.96%.The results of binary logistics regression analysis showed that after excluding the influence of sociodemographic factors such as age,long working hours(weekly working hours greater than 40 h)were the risk factors for occupational stress,depressive symptoms and fatigue accumulation of medical staff(P<0.01),and the longer the working week,the higher the risk of occupational stress,depressive symptoms and fatigue accumulation.Weekly working hours greater than 48 hours are risk factors for insomnia(P<0.01).Conclusion Long working hours are common among delivery workers on food delivery platforms,and long working hours are a risk factor for occupational tension and fatigue.