Petrochemical Industry Workers Research Articles

Behavioral risk assessment of work-related musculoskeletal disorders among workers of petrochemical industries: protocol of a mixed method study

BackgroundMusculoskeletal disorders (MSDs) are one of the most common occupational diseases and the main cause of disability worldwide. Work-related musculoskeletal disorders (WMSDs) are one of the common health risks and the most important cause of absenteeism due to disability in various industries, including the petrochemical industry, in developed and developing countries. These disorders have important social economic, and significant financial consequences due to direct and hidden costs. Health behaviors play a role in both creating and preventing musculoskeletal disorders in employees. Therefore, by identifying the influencing factors on these behaviors, it is possible to strengthen and improve the preventive behaviors of musculoskeletal disorders through educational intervention programs. This study aims to assess the behavioral risk of work-related musculoskeletal disorders, and design and implement an educational intervention to teach effective behaviors in the prevention of musculoskeletal disorders in petrochemical industry workers.MethodsThis study is a mixed-method study implemented in four stages involving the qualitative study, the design and evaluation of an instrument, the design of an experimental randomized clinical trial, and the psychometric evaluation of the instrument and the evaluation of the program. The research community consists of employees working in the petrochemical industry. The volume of samples in the qualitative study with the purposeful sampling method, in the instrument design stage based on the available sampling method, and also in the experimental study, the samples are employees suffering from work-related musculoskeletal disorders, who were selected based on a simple random method from among the employees of the petrochemical industry. Then they will be divided into intervention and control groups. The instruments of this research include a demographic questionnaire, a researcher-made questionnaire for measuring behavior, and two auxiliary instruments including the visual analog scale (VAS) and the Quebec Disability Scale. Evaluation is done in 4 stages: pre-test, immediately, 3, and 6 months after the intervention of both groups. The obtained data will be analyzed using SPSS software.DiscussionMusculoskeletal disorders related (WMSDs) to work can harm employees’ health in various industries, including the petrochemical industry. This study attempts to evaluate the behavioral risk of work-related musculoskeletal disorders among petrochemical industry workers and design and implement an appropriate educational intervention program.Trial registrationIranian Registry of Clinical Trial (IRCT20240321061346N1). Registered on 2024–04-10.Ethics Status: Ethics code: IR.MODARES.REC.1402.251.

The influence of production factors on the formation of the health of workers in the production of synthetic rubbers, preventive measures

The petrochemical industry, which includes, along with the production of basic chemicals for the production of rubber, occupies one of the leading places in terms of potential chemical hazards to the health of workers. The high prevalence of CNID among workers of petrochemical industries is an important socio-economic problem. The issues of reducing the incidence of chronic non-communicable diseases, including those related to working conditions, the protection and preservation of the health of workers in petrochemical industries dictate the need to develop preventive measures. The aim of the study was to study the prevalence of chronic non-communicable diseases in synthetic rubber production workers. Clinical and hygienic studies have been carried out in the production of synthetic rubber. Harmful production factors were assessed at 80 workplaces based on the materials of a special assessment of working conditions and production control data. The health status of 674 employees was studied according to the results of periodic medical examinations. The surveyed workers were represented by apparatchiks (33.2 %), locksmiths for the repair of technological equipment (12.8 %), machinists of pumping and compressor units (10.7 %), locksmiths of KIP and A (9.1 %). A number of clinical and laboratory, functional research methods have been used to assess the state of health. At the workplaces of the production of synthetic rubber, an adverse effect of chemicals on the worker’s body in combination with industrial noise, the severity of labor and microclimate in certain working areas has been established. The working conditions of employees of the main professions are assigned to the third class of the first-second degrees of harmfulness (classes 3.1–3.2). It was found that there were 17.3 % of practically healthy individuals. Among the identified chronic non-communicable diseases, the leading place was occupied by diseases of the musculoskeletal system (31.1 %), disorders of the autonomic nervous system (28.7 %), myopia (22.0 %), hypertension (12.2 %) hearing impairment (10.3 %). When evaluating the results of biochemical blood tests, the most pronounced changes were found in the indicators of lipid metabolism. Excess values of total cholesterol were detected in 40.9 % of employees. A complex of therapeutic and preventive measures has been developed aimed at reducing the risk of the formation of chronic non-communicable diseases, including measures of primary and secondary prevention.

Environmental impact of endocrine-disrupting chemicals and heavy metals in biological samples of petrochemical industry workers with perspective management

Exposure to endocrine disrupting chemicals (EDCs) or heavy metals are synthetic compounds that can lead to negative effect on health, including immune and endocrine system disruption, respiratory problems, metabolic issues, diabetes, obesity, cardiovascular problems, growth impairment, neurological and learning disabilities, and cancer. Petrochemical industry drilling wastes, which contain varying levels of EDCs, are known to pose a significant risk to human health. This study aimed to investigate the levels of toxic elements in biological samples of individuals working in the petrochemical drilling sites. Biological samples, including scalp hair and whole blood, were collected from petrochemical drilling workers, individuals residing in the same residential area, and control age-matched persons from nonindustrial areas. The samples were oxidized by an acid mixture before analysis using atomic absorption spectrophotometry. The accuracy and validity of the methodology were verified through certified reference materials from scalp hair and whole blood. The results showed that the concentrations of toxic elements, such as cadmium and lead, were higher in biological samples of petrochemical drilling employees, while lower essential element levels (iron and zinc) were detected in their samples. This study highlights the significance of adopting better practices to reduce exposure to harmful substances and protect the health of petrochemical drilling workers and the environment. It also suggests that perspective management including policymakers and industry leaders should take measures to minimize exposure to EDCs and heavy metals to promote worker safety and public health. These measures could include the implementation of strict regulations and better occupational health practices to reduce toxic exposure and promote a safer work environment.

Database on the Standardized mortality ratio (SMR all causes and SMR all cancer) for various professions (706 cohorts/groups): the maximum "health worker effect" for cosmonauts and doctors

Researchers have formed a database for work on the evaluation of the indices of the "standardized mortality ratio" (SMR±95% confidence intervals — CI) in comparison with the general population for total mortality and mortality from all malignant neoplasms ("all cancers") for various professions and types of employment (mainly men). The database includes 689 publications (706 cohorts/groups, 67 professions and types of employment).
 Experts have conducted an assessment the presence of the "healthy worker effect" (HWE) in the studies included in the database based on the criterion of the upper 95% CI value of less than one.
 Among all professions and types of employment, scientists have identified HWE in total mortality only in 52%, and in mortality from all types of cancer — only in 28% of cohorts/groups.
 HWE for both indicators simultaneously and only for total mortality occurred in 26% of cases. For 2% of the studies, there is an inverse relationship (absence of HWE for total mortality in the presence of an effect on mortality from all types of cancer), which is most likely accidental.
 There were no strict dependencies between HWE and the carcinogenic potential of activity, although there was a definite trend. 
 The frequency of work with HWE for specific professions identified as the most "unprofitable" work with such heavy metals as Hg, Cd, Pb, Cu (the frequency of HWE is 0% for total mortality and 5% (mercury miners) for mortality from malignant neoplasms; one publication), followed by activities related to dust exposure (talc, quartz, various minerals, etc.; 5% and 6%) and asbestos (10% and 2%). Pilots (89% and 65%), oil and petrochemical industry workers (97% and 56%), as well as doctors (94% and 96%) and cosmonauts/astronauts (100% and 67%; the sample is small) occupied leading positions in the highest frequency of HWE.
 A complete sample of SMR studies of foreign doctors (1886–2017) demonstrated a strict linear decrease in the SMR value in total mortality compared with the population since the 1940s (r=–0.927; p<0.001), with SMR=0.38 (95% CI: 0.01; 0.76) achieved by the 2010s.
 At the same time, mortality from all cancers among doctors was reduced in comparison with the population almost equally for all time periods since 1926 (average SMR=0.6; 95% CI: 0.53; 0.66).
 Possible reasons for the reduced mortality among foreign doctors compared to the population are not only in prevention and professional skills, but probably in better access to medicine and specialists. In connection with professional solidarity, medical care and informing doctors is apparently distinguished by great attention.
 Earlier treatment of non-cancerous pathologies is also important, preventing their transformation into chronic ones, which can subsequently lead to carcinogenic consequences.

Dyslipidemia and its relationship with shift work in petrochemical workers

Shift work disrupts the circadian rhythm, threatens workers’ health, and increases the prevalence of cardiovascular diseases. The relationship between shift work, demographic factors, and the prevalence of dyslipidemia in petrochemical industry workers was examined. The study was carried out on 495 male workers in a petrochemical plant. To examine the indices of prevalence of dyslipidemia, serum levels of LDL, HDL, TG, and total cholesterol were measured. The data were analyzed using SPSS software version 25. The results showed that the prevalence of dyslipidemia was equal to 45.1% and abnormal relative frequencies of TG, HDL, LDL, and total cholesterol were 55.8%, 14.3%, 36.6%, and 46.7% respectively. Shift work had a significant relationship with dyslipidemia so that it alone increased the prevalence of dyslipidemia by 14% (OR = 1.14, 955 C.I = 0.9990–1.280) and taking all the variables into account, it increased dyslipidemia by 7.5% (OR = 1.075, 955 C.I = 1.052–1.098). The results showed that shift work had a significant relationship with the prevalence of dyslipidemia and increased the OR. Therefore, management of diet and proper work scheduling are among the efficient strategies to decrease the metabolic damages caused by dyslipidemia. • Evaluation of Dyslipidemia among workers of a petrochemical industry. • Shift work increased the prevalence of dyslipidemia. • Age and BMI increased OR of Dyslipidemia.

HIGH LEVEL OF THE AMOUNT OF ECG PEAKS SV1+RV5–V6 PREDICT NEW CASES OF HYPERTENSION IN THE ORGANIZED POPULATION OF THE PETROCHEMICAL INDUSTRY WORKERS

Objective: Identify risk factors for new cases of hypertension according to a 10-year prospective study of the organized population of the petrochemical industry workers in Belarus. Design and method: New cases of hypertension were revealed according to a 10-year prospective study in 2004/2014 in the organized population of 1,431 workers of petrochemical industry. In 2004 871 subjects with normal blood pressure were divided into two groups. The first group included 260 workers without adverse working factors, the second group included 611 workers with adverse working factors. The survey included standard questionnaires for detection of cardiovascular risk factors, anthropometric measurements, data from instrumental and laboratory examination. Results: According to a 10-year prospective study, a high incidence of hypertension in the studied population was established (37.5%: 31.5% in persons without adverse working factors and 40.1% in persons with adverse working factors) (p < 0.05). A significant positive relationship was found between the incidence of hypertension and work in harmful working conditions (p < 0.05), the strongest connection of which had psycho-physiological factors of labor intensity (p < 0.01). There was revealed significant positive association between the amount of ECG peaks SV1+RV5–V6 (>24 mm) and the frequency of new cases of hypertension adjusted for age, sex and factor of working conditions (df = 1; x2Wald = 33,0; p < 0,001). There were identified other significant factors affecting new cases of hypertension after adjusting for age, sex and factor of working conditions: systolic (p < 0.001) and diastolic blood pressure (p < 0.001), heredity (p < 0.01), absence of higher education (p < 0.001), smoking in the past and present (p < 0.001), alcohol abuse (p < 0.001), low physical activity (p < 0.001), body mass index (p < 0,001), level of salt taste threshold (p < 0,001), level of triglycerides (p < 0,01), glucose (p < 0,001) and GFR (p < 0,001) according to multifactorial regression analysis. Development of hypertension was also associated with a lack of recreational activities (p < 0.001). Conclusions: In addition to classical risk factors level of the amount of ECG peaks SV1+RV5–V6 > 24 mm is a new predictor of development of hypertension in the Belarusian organized population.

Investigation of abnormal menstruation of female workers in petrochemical industry

Objective: To explore the influencing factors of abnormal menstruation of female workers in a petrochemical enterprise. Methods: A total of 5186 female employees in a petrochemical enterprise were selected as the research objects from July 2018 to December 2019. A questionnaire survey was conducted from four aspects: basic information, occupational status, psychological status at work, reproductive and reproductive health, and a multivariate logistic regression model was used for analysis. Results: Among 5132 female workers, 676 were postmenopausal and 1117 (25.1%) among 4456 non-postmenopausal women had abnormal menstruation in the last 6 months. Logistic regression analysis showed that age (<30、30~35 years) and length of service (≤20 years) were protective factors (OR=0.573, 0.590, 0.798, P<0.05) . Age (40~45、45~50 years old) , sleep duration (<6 h) , premature OR late menopause of maternal relatives, occupational exposure to dust, occupational exposure to chemicals, not wearing earplugs, leave due to health reasons in the last 6 months, reproductive tract infection OR symptoms in the last 6 months, spontaneous abortion, induced abortion, physical fatigue and mental fatigue were risk factors for menstrual abnormalities in female workers (OR=2.318, 5.544, 1.231, 1.199, 1.336, 1.403, 1.351, 1.538, 1.613, 1.584, 1.199, 1.601, 1.936, P<0.05) . Conclusion: The abnormal menstruation of female workers is affected by many factors in the occupational process, and specific measures should be taken to improve the reproductive health of female workers.

Assessment of Occupational Exposure to BTEX in a Petrochemical Plant via Urinary Biomarkers

This work presents the results of the first Serbian monitoring campaign performed to assess the occupational exposure of petrochemical industry workers to benzene (B), toluene (T), ethylbenzene (E), and xylene (X), known collectively as BTEX. The following urinary biomarkers were investigated: phenol, hippuric acid, o-Cresol, p-Cresol, and creatinine. BTEX compounds were collected in 2014 using Casella passive samplers. Multivariate statistical analysis was performed to put in evidence the correlation between the BTEX measured in air and the concentration of urinary biomarkers. While the results indicate an elevated presence of benzene in the air in the working environment studied that surpasses the national and European Occupational Exposure Limits (OEL), the levels of the remaining (TEX) parameters measured were below the OEL. The high relative standard deviations (RSD) for the concentrations of each BTEX compound (68–161 mg m−3) point toward an intensive occupational exposure to BTEX. This was confirmed by relevant urine biomarkers, particularly by the mean values of phenol, which were ten and fourteen times higher than the ones found in the control group (14–12 mg g−1 of creatinine). On average, workers are at a higher risk of developing cancer (6.1 × 10−3), with risk levels exceeding the US EPA limits. Benzene levels should therefore be maintained under tight controls and monitored via proper urinary biomarkers.

Evaluation of airborne exposure to volatile organic compounds of benzene, toluene, xylene, and ethylbenzene and its relationship to biological contact index in the workers of a petrochemical plant in the west of Iran.

Nowadays, workers in petrochemical industry might be exposed to organic volatile compounds, including benzene, toluene, ethylbenzene, and xylene (BTEX). The aim of this study was to investigate the concentration of BTEX contaminations and the biological index in employees of petrochemical sites in the west of Iran. The study was conducted as a cross-sectional study on 30 stations and 60 inhalation and biological samples collected in winter and summer. The NIOSH 2549 and 1501 methods were used for sampling and analyzing the inhaled samples. Gas chromatography-mass spectrometry (GC-MS) equipped with flame ionization detector and high-performance liquid chromatography (HPLC) was used to measure the volatile contaminations. The results showed that the mean concentrations of benzene, toluene, and xylene were significantly different in summer and winter. Significant and strong correlations were observed between the concentrations of benzene, toluene, and xylene and the biological values (r > 0.7). Moreover, the concentration of benzene (β = 0.836), toluene (β = 0.718), and xylene (β = 0.786) predicted the changes in their biological values. Given the hazardous concentrations of benzene and toluene in industrial plants and the correlation of the concentration levels and biological values, management and control strategies should be implemented to eliminate and reduce the pollutants and the effects.

Cardiovascular risk in petrochemical workers

Introduction. The high prevalence of diseases of the circulatory system of workers in various sectors of the economy, the lack of data on the effects of harmful production factors on the formation of cardiovascular diseases in petrochemical industry workers justify the importance of conducting special studies on these petrochemical complex plants with the aim of assessing cardiovascular risk with the subsequent development of preventive measures. Material and methods. The objects of the study were workers in the production of monomers (ethylene, propylene, ethylbenzene, isoprene, divinyl) of petrochemical enterprises. Hygienic studies of the working conditions of workers included an assessment of the factors of the working environment and the labor process using generally accepted methods. Comprehensive clinical examination of workers included periodic examinations (n = 2634) with calculation of total and relative cardiovascular risk using the SCORE system, using questionnaire data, a Reeder L questionnaire and an in-depth clinical diagnostic medical examination (n = 101) with the definition total cardiovascular risk. Results. The most significant occupational factors of the labor process for workers in the main profession - panmen were established to include the combination of a chemical factor with the occupational noise and labor intensity, with an overall assessment of working conditions 3.2. The class of working conditions of workers of the comparison group (locksmith in instrumentation and automation corresponds to the permissible). There were revealed a high prevalence of arterial hypertension and other factors of cardiovascular risk. A higher dependence of the arterial hypertension level on age and length of service in the group of panmen was established when compared to the mechanicians of instrumentation and automation. Using mathematical models of multiple regression, the likely dynamics of the level of arterial hypertension and the left ventricular myocardial mass index were calculated under the influence of increasing age and other risk predictors. Conclusion. The results of a clinical study showed workers with severe arterial hypertension, a high and very high risk of death from cardiovascular disease on the SCORE scale, a high and very high overall cardiovascular risk, signs of dyslipidemia, obesity, high stress levels to require close attention. It is important to timely diagnose lesions of target organs, to conduct rational prevention aimed at reducing risk factors. According to the results of the study, there were developed preventive measures aimed at reducing cardiovascular morbidity and cardiovascular risk, prolonging the longevity of workers in petrochemical industries.

Cardiovascular risk in petrochemical workers

Introduction. The high prevalence of diseases of the circulatory system of workers in various sectors of the economy, the lack of data on the effects of harmful production factors on the formation of cardiovascular diseases in petrochemical industry workers justify the importance of conducting special studies on these petrochemical complex plants with the aim of assessing cardiovascular risk with the subsequent development of preventive measures. Material and methods. The objects of the study were workers in the production of monomers (ethylene, propylene, ethylbenzene, isoprene, divinyl) of petrochemical enterprises. Hygienic studies of the working conditions of workers included an assessment of the factors of the working environment and the labor process using generally accepted methods. Comprehensive clinical examination of workers included periodic examinations (n = 2634) with calculation of total and relative cardiovascular risk using the SCORE system, using questionnaire data, a Reeder L questionnaire and an in-depth clinical diagnostic medical examination (n = 101) with the definition total cardiovascular risk. Results. The most significant occupational factors of the labor process for workers in the main profession - panmen were established to include the combination of a chemical factor with the occupational noise and labor intensity, with an overall assessment of working conditions 3.2. The class of working conditions of workers of the comparison group (locksmith in instrumentation and automation corresponds to the permissible). There were revealed a high prevalence of arterial hypertension and other factors of cardiovascular risk. A higher dependence of the arterial hypertension level on age and length of service in the group of panmen was established when compared to the mechanicians of instrumentation and automation. Using mathematical models of multiple regression, the likely dynamics of the level of arterial hypertension and the left ventricular myocardial mass index were calculated under the influence of increasing age and other risk predictors. Conclusion. The results of a clinical study showed workers with severe arterial hypertension, a high and very high risk of death from cardiovascular disease on the SCORE scale, a high and very high overall cardiovascular risk, signs of dyslipidemia, obesity, high stress levels to require close attention. It is important to timely diagnose lesions of target organs, to conduct rational prevention aimed at reducing risk factors. According to the results of the study, there were developed preventive measures aimed at reducing cardiovascular morbidity and cardiovascular risk, prolonging the longevity of workers in petrochemical industries.

Prevalence of Depression, Anxiety, and Stress in Workers of Petrochemical Industry: a cross sectional study in Assaluyeh port

Introduction: Mental disorders such as depression, anxiety, and stress are important factors in determining the life quality as well as many social and economic problems in workers' life. The goal of this study was to determine the prevalence of depression, anxiety, and stress among workers of the petrochemical industry in Assaluyeh port in 2017. Methods: This cross-sectional study was conducted on 167 workers employed in the petrochemical industry. Data were collected using a two-part questionnaire including field information and standard depression, anxiety, and stress screening questionnaire (DASS-21). Data were analyzed in SPSS20 using descriptive statistics, ANOVA, and Tukey post hoc test. Results: The prevalence of depression, anxiety, and stress were 38.92, 44.31, and 29.34 percent in the present study. Moreover, comparison of depression, anxiety, and stress with demographic variables showed a significant relationship between age, marital status, education, and job satisfaction (P &lt;0.050). Conclusion: Prevalence of depression, anxiety, and stress was in the range of 29-44 percent among the workers. Demographic factors including age, marital status, education, and job satisfaction indicated a significant relationship with depression, anxiety, and stress. Further field studies are recommended to identify other factors related to these disorders. We should also plan interventions to support and empower workers in the workplace.

Influencing factors for reproductive health of female workers in petrochemical industry

Objective: To investigate the reproductive health status of female workers in petrochemical industry, and to provide a reference for improving reproductive health status and developing preventive and control measures for female workers in petrochemical industry. Methods: A face-to-face questionnaire survey was performed from January to October, 2016. The Questionnaire on Women's Reproductive Health was used to investigate the reproductive health of female workers in petrochemical industry. The multivariate logistic regression model was used to identify the influencing factors for reproductive health of female workers in petrochemical industry. Results: Among the 7485 female workers, 1 268 (40.9%) had abnormal menstrual period, 1 437 (46.4%) had abnormal menstrual volume, 177 (28.5%) had hyperplasia of mammary glands, and 1 807 (24.6%) had gynecological inflammation. The reproductive system diseases in female workers in petrochemical industry were associated with the factors including age, marital status, education level, unhealthy living habits, abortion, overtime work, work shift, workload, video operation, occupational exposure, positive events, and negative events, and among these factors, negative events (odds ratio[OR]= 1.856) , unhealthy living habits (OR=1.542) , and positive events (OR=1.516) had greater impact on reproductive system diseases. Conclusion: Many chemical substances in the occupational environment of petrochemical industry can cause damage to the reproductive system, which not only affects the health of the female workers, but also poses potential threats to the health of their offspring. Occupational exposure, unhealthy living habits, overtime work, and work shift have great influence on reproductive system diseases in female workers.

Does Psychosocial Work Environment Factors Predict Stress and Mean Arterial Pressure in the Malaysian Industry Workers?

Psychosocial risks are considered as a burning issue in the Asia-Pacific region. The aim of this study was to investigate the impact of psychosocial work environment factors on health of petrochemical industry workers of Malaysia. In lieu to job demands-resources theory, significant positive associations were found between quantitative demands, work-family conflict, and job insecurity with stress, while a significant negative association of role clarity as a resource factor with stress was detected. We also found that quantitative demands were significantly associated with the mean arterial pressure (MAP). Multistage sampling procedure was used to collect study sample. Structural Equation Modeling was used to identify relationship between the endogenous and exogenous variables. Finally, the empirically tested psychosocial work environment model will further help in providing a better risk assessment in different industries and enterprises.

Development and validation of a new safety climate scale for petrochemical industries.

While a considerable body of research has studied safety climate and its role as a leading indicator of organizational safety, much of this work has been conducted with Western manufacturing samples. The current study puts emphasis on the cross-validation of a safety climate model in the non-Western industrial context of Iranian petrochemical industries. The current study was performed in one petrochemical company in Iran. The scale was developed through conducting a literature review followed by a qualitative study with expert participation. After performing a screening process, the initial number of items on the scale was reduced to 68. Ten dimensions (including management commitment, workers' empowerment, communication, blame culture, safety training, job satisfaction, interpersonal relationship, supervision, continuous improvement, and reward system) together with 37 items were extracted from the exploratory factor analysis (EFA) to measure safety climate. Acceptable ranges of internal consistency statistics for the sub-scales were observed. Confirmatory factor analysis (CFA) confirmed the construct validity of the developed safety climate scale for the petrochemical industry workers. The results of reliability showed that the Cronbach's alpha coefficient for the designed scale was 0.94. The ICC was obtained 0.92. This study created a valid and reliable scale for measuring safety climate in petrochemical industries.

MGMT hypomethylation is associated with DNA damage in workers exposed to low-dose benzene

Objective: This study aims to assess the effects of low-dose benzene on DNA damage and O6-methylguanine-DNA methyltransferase (MGMT) methylation in occupational workers.Materials and methods: We recruited 96 nonsmoking male petrochemical industry workers exposed to low-dose benzene and 100 matched control workers. Urinary S-phenylmercapturic acid (SPMA) and S-benzylmercapturic acid (SBMA) were measured for indicating internal exposure of benzene and toluene. The degree of DNA damage was determined by the Comet assay. The levels of MGMT methylation were detected quantitatively by bisulphite-PCR pyrosequencing assay.Results: The benzene-exposed workers had significantly higher levels of urinary SPMA, degree of DNA damage but decreased MGMT methylation than the controls (all p < 0.05). In contrast, the level of urinary SBMA does not differ between benzene-exposed workers and the controls. In all participants, MGMT methylation was negatively associated with the urinary SPMA and the degree of DNA damage, indicating that epigenetic regulation might be involved in response to low-dose benzene exposure-induced genetic damage.Discussion and conclusion: MGMT methylation could be a potent biomarker associated with low-dose benzene exposure and benzene-induced DNA damage.

Visual functions of workers exposed to organic solvents in petrochemical industries.

Aim:The purpose of this study was to evaluate the visual functions of workers exposed to organic solvents in petrochemical industries.Materials and Methods:Thirty workers from the petroleum refinery and 30 age-matched controls (mean age) were recruited. Visual functions and occupational exposure levels were assessed among both the groups. Visual acuity, contrast sensitivity, color vision, and visual fields were evaluated at the workplace. The biological samples, namely blood and urine, were collected at the workplace and transported to the laboratory for analysis. The urinary excretion of hippuric and methylhippuric acid as well as creatinine was measured by high performance liquid chromatography.Results:The mean age of the workers and controls were 39.7 ± 7.6 years and 38.6 ± 8.1, years respectively. The mean years of experience of the workers were 15.6 ± 6.8 years. Visual acuity was >0.01 LogMAR among both the control and case groups. The contrast sensitivity was reduced at 12cpd among workers. Comparison between groups was done using independent sample t-test. The mean difference in color confusion index was 0.11 ± 0.05 (P = 0.037*). The mean difference in visual fields was −0.31 ± 0.36 dB (P = 0.933). The mean difference in urinary hippuric acid level (urinary metabolite of toluene) between the groups was 0.19 ± 0.96 g/g creatinine (P = 0.049FNx01). The mean difference in the excretion of methylhippuric acid (urinary metabolite of xylene) was 0.06 ± 0.04g/g creatinine (P = 0.154). We also found that exposure was a significant risk factor for color vision defect with an odds ratio of 4.43 (95% CI: 1.36–14.4); P = 0.013.Conclusion:The study results showed that contrast sensitivity and color vision were affected among workers in petrochemical industry.

Periodontal tissue status and «lipid peroxidation - antioxidant protection» system in saliva and gingival fluid in petrochemical industry workers

Aim. To study periodontal tissue status and «lipid peroxidation - antioxidant protection» system in saliva and gingival fluid in petrochemical industry workers.&#x0D; Methods. 185 employees of JSC «Experimental Plant Neftechim» were included into the study. Besides the evaluation of dental status saliva and gingival fluid were analyzed for lipid peroxidation products - diene and triene conjugates, malondialdehyde, hydroperoxides and Schiff bases.&#x0D; Results. The rate of chronic generalized periodontitis in petrochemical industry workers was 100%, including moderate (47.03%), severe (35.13%) and mild (17.84%) degree. Enhancement of lipid peroxidation and antioxidant defense system activity were detected (in mild and moderate chronic generalized periodontitis) with increasing inflammatory and destructive processes in periodontal tissues. In severe chronic generalized periodontitis reduction in the antioxidant protection activity was observed along with the increasing of lipid peroxidation. Correlation analysis revealed a direct relationship between the periodontal tissue status and «lipid peroxidation - antioxidant protection» system.&#x0D; Conclusion. The prophylactic work should be organized among the petrochemical industry employees aiming to decrease risks of diseases; using the obtained data can be used in clinical practice to identify high-risk groups of patients with periodontal pathology.

Effect of exposure to a mixture of organic solvents on hearing thresholds in petrochemical industry workers.

Hearing loss is one of the most common occupational diseases. In most workplaces, workers are exposed to noise and solvents simultaneously, so the potential risk of hearing loss due to solvents may be attributed to noise. In this study we aimed to assess the effect of exposure to mixed aromatic solvents on hearing in the absence of exposure to hazardous noise. In a cross-sectional study, 99 workers from the petrochemical industry with exposure to a mixture of organic solvents whose noise exposure was lower than 85 dBA were compared with 100 un-exposed controls. After measuring sound pressure level and mean concentration of each solvent in the workplace, pure-tone-audiometry was performed and the two groups were compared in terms of high-frequency and low-frequency hearing loss. T-tests and Chi-square tests were used to compare the two groups. The mean hearing threshold at all frequencies among petrochemical workers was normal (below 25 dB). We did not observe any significant association between solvent exposure and high-frequency or low-frequency hearing loss. This study showed that temporary exposure (less than 4 years) to a mixture of organic solvents, without exposure to noise, does not affect workers' hearing threshold in audiometry tests.

Biological monitoring of petrochemical industry workers exposed to benzene, toluene, xylenes, methyl ethyl ketone, and phenol in Southern Iran

Received: July 2015, Accepted: August 2015 Background: Volatile organic compounds (VOCs), including carcinogens and toxic compounds, are produced in petrochemical industries. We undertook this study in order to study workers’ respiratory exposure to different VOC concentrations and compare the results with the urinary levels of its metabolites and study the correlation between them in petrochemical industries. Materials and Methods: Exposure to benzene, toluene, xylene isomers, phenol, and methyl ethyl ketone (MEK) was evaluated in 104 male subjects using personal sampling pump and charcoal sorbent tube at the breathing zone and analyzed using gas chromatography–mass spectrometry (GC-MS). The urine samples were analyzed using high-performance liquid chromatography (HPLC-UV) and gas chromatography-flame ionization detector (GC-FID). Results: The mean concentration of urinary trans,trans-muconic acid (t,t-MA), was 1431 µg/g creatinine and hippuric acid, methyl hippuric acid, phenol, and MEK were, 0.394, 0.444, 0.098 g/g creatinine, and 0.15 mg/l. The mean concentration of benzene in the breathing zone was greater than the threshold limit value (TLV) recommended by the American Conference of Governmental Industrial Hygienists (ACGIH). Conclusions: In this study, a more significant relationship was found between benzene in breathing zone and urinary t,t-MA in those exposed to benzene in concentrations higher than 1 ppm (r 2 = 0.89) than lower than 1 ppm. Moreover, the same results were observed for other hydrocarbons and their level of urinary biological index. A more significant relationship was observed between phenol in breathing zone and urine through exposure to airborne phenol in concentrations of higher than 0.049 ppm than lower than 0.049 ppm (r 2 = 0.75). The relationship between MEK in breathing zone and urinary MEK was more significant in concentrations of higher than 0.1 ppm (r 2 = 0.79) than lower than 0.1 ppm.