Association of cumulative dust exposure with hypertension among workers in a large steel mill: an analysis with restricted cubic spline model

  Objective  To analyze the relationship between cumulative dust exposure (CDE) and hypertension among steel workers.

  Methods  We conducted a survey among 7 660 production workers (7 023 males and 637 females) in a large steel mill during February – June 2017 and March – July 2018. The workers' information on demographics, occupation history, and blood pressure were collected when the workers had their routine physical examination. CDE values were estimated for all the workers based on workplace dust monitoring data. Restrictive cubic spline model was used to assess the dose-response relationship between CDE and hypertension; the correlation between CDE and hypertension was analyzed with logistic regression model.

  Results  Of all the workers, 64.70% had exposed to dust and the CDE median was 26.15 mg/m³·year for the exposed workers. The hypertension prevalence rate was 25.60% among the workers. Factors including gender, age, marital status, education level, body mass index (BMI), smoking, alcohol drinking, family hypertension history, and cumulative dust exposure were all related to hypertension among the workers. There was a nonlinear dose-response relationship between CDE and hypertension for the workers with various dust exposure at the CDE values of < 18.78 mg/m³·year, 18.78 mg/m³·year –, and ≥ 58.74 mg/m³·year based on restricted cubic spline model analysis. The workers with the CDE value of ≥ 58.74 mg/m³·year were at a significantly increased risk of hypertension (odds ratio = 1.74, 95% confidence interval: 1.28 – 2.36) compared to those with the CDE value of < 18.78 mg/m³·year after adjusting for potential confounders.

  Conclusion  Among steel workers, hypertension is related to a variety of factors and the workers with high occupational dust exposure have an increased hypertension risk compared to the workers with low occupational dust exposure.