The destruction of circadian rhythms by night shift work affects major circadian genes, which are known to play a role in advancing or killing the cell cycle through tumor suppressor genes. To find out whether night shift work affects the incidence of colorectal cancer, which was found to be associated with long-term night shift work in previous studies, we surveyed effect of night shift work on colorectal polyps that have a higher incidence than colorectal cancer and can progress to colorectal cancer.

To examine the correlation between rotating night shifts and colorectal polyps, a survey was conducted with 299 men aged 40–60 years from two university hospitals. We examined lifestyle, work history, work patterns, and colonoscopy results. The differences in prevalence among the groups was compared, and prevalence ratio (PR) was calculated via generalized linear modeling.

The prevalence of colorectal polyps in night shift and non-shift workers were 53.0% and 33.5%, respectively. After adjusting for age, smoking status, dietary habits, family history of colorectal cancer, obesity, job type, night shift work (PR: 1.13, 95% CI: 1.02–1.25) was a risk factor of colorectal polyps.

The risk of colorectal polyps was greater in night shift workers than non-shift workers. Also risk of colorectal polyp was higher in older group. Our study investigated colorectal polyp instead of colorectal cancer and lacks information about types and gene mutations of colorectal polyps. Further study is needed to clarify effect of night shift work on development of colorectal cancer.

The organizational justice model can evaluate job stressor from decision-making process, attitude of managerial or senior staff toward their junior workers, and unfair resource distribution. Stress from organizational injustice could be harmful to workers' mental health. The purpose of this study is to explore the association between organizational justice and depressive symptoms in a securities company.

To estimate organizational justice, a translated Moorman's organizational justice evaluation questionnaire (Korean) was employed. Cronbach's α coefficient was estimated to assess the internal consistency of the translated questionnaire. To assess depressive symptoms, the Center for Epidemiologic Studies Depression (CES-D) scale was used. The link between the sub-concepts of the organizational justice model and depressive symptoms was assessed utilizing multiple logistic regression models.

The risk of depressive symptoms was significantly higher among workers with higher levels of all subcategory of organizational injustice. In the full adjusted model odds ratio (OR) of higher level of procedural injustice 2.79 (95% confidence interval [CI], 1.58–4.90), OR of the higher level of relational injustice 4.25 (95% CI, 2.66–6.78), OR of higher level of distributional injustice 4.53 (95% CI, 2.63–7.83) respectively. Cronbach's α coefficient of the Korean version was 0.93 for procedural justice, 0.93 for relational justice, and 0.95 for distributive justice.

A higher level of organizational injustice was linked to higher prevalence of depressive symptoms among workers in a company of financial industry.