Objective To analyze the current status and influencing factors of elevated blood pressure among employees in a large petroleum refining enterprise in Hainan Province. Methods A total of 940 workers from a petroleum refining enterprise in Hainan Province was selected as the study subjects using the convenience sampling method. The results of their health status survey, occupational medical examination, and occupational stress measurement were collected. Results The detection rate of elevated blood pressure in the study subjects was 23.9% (225/940), with the detection rate of normal blood pressure and hypertension of 17.7% (166/940) and 6.3% (59/940), respectively. The detection rate of occupational stress was 28.8% (271/940). The result of multivariate logistic regression analysis showed that workers aged 30 -<40, 40 -<50, and ≥50 years had a higher risk of elevated blood pressure than those aged <30 years after controlling for confounding factors such as gender, residential address, length of service, education level, personal monthly income, smoking status, physical exercise, salt intake, oil intake, occupational stress, and high temperature exposure (all P<0.05). Workers in the body mass index (BMI) overweight group and obese group had a higher risk of elevated blood pressure than those in the normal group (all P<0.05). The risk of elevated blood pressure was higher in workers who drinks than those who did not (P<0.05). Workers exposed to noise levels of 85-90 dB(A) had a lower risk of elevated blood pressure compared to those exposed to noise levels >90 dB(A) (P<0.05). Conclusion Age, BMI, drinking status, and noise exposure levels are independent influencing factors for elevated blood pressure among workers in this petroleum refining enterprise. Blood pressure management should be strengthened for workers aged ≥30 years, overweight, obesity, alcohol consumption and with noise exposure intensity > 90 dB(A).

Background Workers engaged in benzene-exposed or benzene-containing solvent-exposed operations in China are predominantly subjected to a low concentration of benzene series compounds, and prolonged exposure to low concentrations of benzene, toluene, and xylene (BTX) may have implications for blood pressure. Objective To investigate the influence of low-concentration BTX exposure on the blood pressure of workers, aiming to provide a basis for enterprises to devise associated health management strategies to mitigate the occurrence of hypertension among workers exposed to low concentrations of BTX. Methods Using a cross-sectional design, 884 workers from a petroleum refining enterprise in Hainan who participated in an occupational health examination in 2022 were selected as the study population, and were divided into an exposure group of 649 workers and a control group of 235 workers based on their reporting of BTX exposure or not. Data on workplace BTX concentrations and health examinations of the study subjects were collected and questionnaires were administered. In addition, S-phenylmercapturic acid (S-PMA), hippuric acid (HA), and methyl hippuric acid (MHA, including the three isomers 2-MHA, 3-MHA, and 4-MHA) were measured in the urine of the workers using high-performance liquid chromatography-tandem triple quadrupole mass spectrometry to assess internal BTX burden. The effects of low-concentration BTX exposure on blood pressure were analyzed. Results In 2022, the concentrations of benzene, toluene, and xylene of all monitoring points did not exceeded the national limits by either time-weighted average (TWA) or short-term exposure limit (STEL), indicating low-concentration BTX exposure. Regarding the internal burden of BTX, the concentrations of benzene metabolite S-PMA, toluene metabolite HA, and xylene metabolites 3-MHA and 4-MHA in the urine samples in the exposure group were higher than those in the control group (P < 0.05). The correlation analysis showed a positive correlation between urinary S-PMA concentration and diastolic blood pressure in the workers (r=0.265, P < 0.05). Differences in systolic and diastolic blood pressure distributions were statistically significant among workers grouped by sex, age, work years, educational levels, monthly income, body mass index (BMI), alcohol use, dietary oil, and types of residential address (P < 0.05). Significant differences in systolic blood pressure distribution were observed among workers by smoking status and levels of labor intensity (P < 0.05). Compared with the control group, the workers in the exposure group exhibited a significant increase in diastolic blood pressure (P < 0.05). The results of multiple linear regression showed that age, sex, and BMI had statistically significant effects on systolic blood pressure (P < 0.05), while age, work years, and BMI had statistically significant effects on diastolic blood pressure (P < 0.05). The systolic blood pressure of age > 35 years, male, overweight and obese workers was significantly higher than that of age ≤ 35 years, female, and underweight workers, and the diastolic blood pressure of age > 35 years, work years > 5 years, and obese workers was higher than age ≤35 years, ≤5 years of service, and underweight workers. Low-concentration BTX exposure was one of the main influencing factors for elevated diastolic blood pressure, and the exposed workers showed a 1.337 mmHg increase in diastolic blood pressure compared to the control group (P < 0.05). Conclusion Low-concentration BTX exposure, work years > 5 years, and obesity may elevate blood pressure among petroleum refininig workers. Regular blood pressure monitoring and enhanced health interventions for this occupational group are warranted.