In China, noise is one of the major occupational harmful factors in the workplace of petroleum workers, and long-term exposure to noise can cause microcirculation disorder and further several cardiovascular diseases.

This study explores the effects of occupational noise exposure on nailfold microcirculation in petroleum workers.

A total of 1 104 petroleum workers who received annual occupational health examination of a petroleum company from May to October 2018 were enrolled for this study. The workstations of the petroleum workers included water injection, external transport, underground operation, electrical welding, heating, and laboratory. Socio-demographic characteristics (such as sex, age, and education level), lifestyle behaviors (such as smoking, drinking, physical exercise), and occupational factors (such as seniority, shift work, and history of noise exposure) were collected through a questionnaire survey interviewed face-to-face. Height and body weight were also measured. Nailfold microcirculation images and videos were recorded by trained researchers, and two independent physicians provided blinded diagnostic evaluations on nailfold microcirculation. The petroleum workers were divided into a noise group and a control group based on whether they were continuously exposed to noise for 1 year or more8 h per day or 40 h per week equivalent sound pressure level ≥ 80 dB (A). A multi-factor logistic regression model was used to analyze the effect of occupational noise exposure on nailfold microcirculation in the petroleum workers.

Of the 1 104 participants, the range of age was 19-64 years, and most were male (66.2%). The prevalence rate of nailfold microcirculation disorder in the petroleum workers was 33.8%. The prevalence rate of nailfold microcirculation disorder was higher in the noise group than in the control group (42.4% vs 21.4%, P < 0.001). The prevalence rates of nailfold microcirculation disorder were different among the petroleum workers of different sex, age, body mass index (BMI), smoking, drinking, physical exercise, seniority, and shift work groups (P < 0.05). The prevalence rates of nailfold microcirculation disorder were higher in male, BMI ≥ 28.0 kg·m^-2, smoking, drinking, non-physical exercise, and shift work groups than in their respective reference groups (P < 0.05). The prevalence rate of nailfold microcirculation disorder was the lowest in the group of 20-30 years of working age (28.1%). After adjusting for sex, age, BMI, smoking, drinking, physical exercise, and shift work, the multi-factor logistic regression results showed that the OR (95%CI) of nailfold microcirculation disorder was 2.50 (1.86-3.36) for those with noise exposure versus those without.

Noise may be an important risk factor of nailfold microcirculation disorder of petroleum workers.