Personal exposure to benzene and 1,3-butadiene during petroleum refinery turnarounds and work in the oil harbour

Industry-wide review of potential worker exposure to 1,3-butadiene during chemical manufacturing and processing as a reactant

Among the first 20 high-priority chemical substances selected by USEPA to undergo risk evaluation as part of the Toxic Substances Control Act, as amended by the Frank R. Lautenberg Chemical Safety for the 21st Century Act of 2016 is 1,3-butadiene (1,3-BD). Because much of the literature related to occupational exposure to 1,3-BD is associated with the use of the substance in synthetic rubber production and few data have been published for exposures to 1,3-BD manufacturing workers, existing industrial hygiene data collected at facilities where the substance is manufactured or processed as a reactant were compiled and analyzed. The dataset was comprised of personal air samples collected between 2010 and 2019 at facilities located throughout the United States and was compiled into a single database using a uniform data collection template. Data designated by the companies as full-shift were stratified by job group and one of three operational conditions of the workplace: routine, turnaround, and non-routine. Data designated by the companies as short-term and task-level were stratified by task description, sample duration, and operational condition. The final aggregated database contained a total of 5,676 full-shift personal samples. Mean concentrations of 1,3-BD for the job groups ranged from 0.012 ppm to 0.16 ppm. High-end estimates of 1,3-BD air concentrations for the job groups under routine operations ranged from 0.014 ppm to 0.23 ppm. The aggregated database also included 1,063 short-term and task-level personal samples. For short-term samples (< =15 min), mean concentrations ranged from 0.49 ppm to 3.9 ppm, with the highest concentrations observed for the cleaning and maintaining equipment tasks. For task samples with durations greater than 15 min, mean concentrations ranged from 0.49 to 3.6 ppm, with the highest concentrations observed for the unloading and loading task. In addition to the personal air sampling records, information on the use of PPE during various tasks was compiled and analyzed. This data set provides robust quantitative air concentration data and exposure control information for which occupational exposures to 1,3-BD in the Manufacturing and Processing as a Reactant condition of use can be assessed.

Accurate low-dose exposure assessment of benzene and monoaromatic compounds by diffusive sampling: sampling and analytical method validation according to ISO 23320 for radiello® samplers packed with activated charcoal

The research study aimed at providing an accurate low-dose benzene exposure assessment method, by validating diffusive monitoring techniques for benzene personal exposure measurements at workplaces where benzene concentrations are expected in the low ppb range, such as in the present-day chemical, petrochemical, foundry, and pharmaceutical industry. The project was aimed at addressing the need for a robust and fully validated method to perform personal exposure measurements considering that the occupational exposure limit value for benzene is going to be significantly lowered in the next few years. Diffusive sampling offers a reliable alternative to pumped sampling methods, intrinsic safety in potentially explosive atmospheres, lightness, and ease of use. In this study, the radiello® diffusive sampler, with the packed activated charcoal RAD130 adsorbing substrate [suitable for solvent desorption and analysis by high-resolution gas chromatography-flame ionization detection (HRGC-FID)], was used. The experiments have been conducted following the ISO 23320 standard in the range from 0.005 to 0.1 ppm (16 to 320 μg/m3), yielding a full validation of the sampling and analytical method. The sampler performances have fulfilled all requisites of the ISO 23320 standard, in particular: bias due to the selection of a non-ideal sorbent is lower than 10% (no significant back diffusion of benzene due to concentration change in the atmosphere); bias due to storage of samples for up to 2 months is lower than 10%; nominal uptake rate for benzene on RAD130 is 74.65 mL/min; and expanded uncertainty of the sampling and analytical method is 20.6%. The sampling and analytical method is therefore fit-for-purpose for the personal exposure measurements aimed at testing compliance with occupational exposure limit values for benzene. The method is also fit for short-duration exposure monitoring related to specific tasks, and other volatile organic compounds, usually found in the same workplaces, such as aliphatic and aromatic hydrocarbons and some oxygenated compounds, have also been studied. In particular, n-hexane and isopropyl benzene, whose classification is currently under revision, can be efficiently monitored by this technique.

Risks of Leukemia in Various Industrial Groups in Korea: A Retrospective National Cohort Study

It is known that occupational exposure to specific agents is associated with leukemia. However, whether the occupational risks of leukemia differ among various industrial groups remains unclear. Therefore, the purpose of this study was to elucidate the occupational risks of leukemia among different worker groups by industry. Data for a total of 11,050,398 people from the National Health Insurance System's claim data from 2007 to 2015 were analyzed. By cohort inclusion of workers whose industry had not changed for three years and with total workers as a control group, the risk for a specific industry group was expressed as an age-standardized incidence ratio (SIR). Among groups by industry, 'Manufacture of motor vehicles and engines for motor vehicles', 'Sale of motor vehicle parts and accessories', and 'Personal care services' showed significantly higher SIRs. In division analysis, the 'Manufacture of other machinery and equipment' and 'Waste collection, treatment and disposal activities' divisions showed significantly higher SIRs than other divisions. We identified an increased risk of leukemia in workers of certain industries in Korea. Based on the results of this study, it is necessary to create a policy to protect workers at risk of leukemia. Various additional studies are needed to protect workers by revealing more precise relationships between individual hazardous substances, processes, and leukemia.

Occupational health risk assessment of the benzene exposure industries: a comprehensive scoring method through 4 health risk assessment models

Benzene is one of the most common occupational hazards in the working environment which was in the list of group 1 carcinogens. This study applied four occupational health risk assessment models: EPA model; MOM model of Singapore; the International Council on Mining and Metals (ICMM) model, and the Technical guide WS/T 777-2021 of China. The models assessed both non-carcinogenic and carcinogenic effects of benzene for 1629 employees in 50 factories in Jiangsu Province (China) who were exposed to benzene in the working environment and analysis the risk between industries by principal component analysis (PCA) method. The highest occupational health hazard of benzene among the five industries is petroleum processing industry, then followed by chemical products manufacturing industry, special equipment manufacturing industry, wood processing and products industry, and at last the pharmaceutical manufacturing industry. The population of abnormal routine blood parameters in the subjects was mostly in the "wood products industry" group, and the concentration of benzene in "wood products industry" group is the lowest in 5 groups. The industries with low exposure concentration have higher blood abnormality rates; this may be caused by the fact that blood damage is more secretive under low occupational health risk.

Benzene Exposure From Selected Work Tasks on Offshore Petroleum Installations on the Norwegian Continental Shelf, 2002-2018

OBJECTIVES

Work on offshore petroleum installations may cause exposure to benzene. Benzene is a carcinogenic agent, and exposure among workers should be as low as reasonably practicable. We aimed to assess short-term (less than 60 min) benzene exposure from the most frequent work tasks on offshore installations on the Norwegian continental shelf and identify determinants of exposure. In addition, we aimed to assess the time trend in task-based benzene measurements from 2002 to 2018.

METHODS

The study included 763 task-based measurements with a sampling duration of less than 60 min, collected on 28 offshore installations from 2002 to 2018. The measurements were categorized into 10 different tasks. Multilevel mixed-effect Tobit regression models were developed for two tasks: sampling and disassembling/assembling equipment. Benzene source, season, indoors or outdoors, design of process area, year of production start, sampling method, and work operation were considered as potential determinants for benzene exposure in the models.

RESULTS

The overall geometric mean (GM) benzene exposure was 0.02 ppm (95% confidence intervals 95%(CI: 0.01-0.04). The pipeline inspection gauge (PIG) operation task was associated with the highest exposure, with a GM of 0.33 ppm, followed by work on flotation cells, disassembling/assembling, and sampling, with GMs of 0.16, 0.04, and 0.01 ppm, respectively. Significant determinants for the disassembling/assembling task were work operation (changing or recertifying valves, changing or cleaning filters, and breaking pipes) and benzene source. For sampling, the benzene source was a significant determinant. Overall, the task-based benzene exposure declined annually by 10.2% (CI 95%: -17.4 to -2.4%) from 2002 to 2018.

CONCLUSIONS

The PIG operation task was associated with the highest exposure out of the ten tasks, followed by work on flotation cells and when performing disassembling/assembling of equipment. The exposure was associated with the type of benzene source that was worked on. Despite the decline in task-based exposure in 2002-2018, technical measures should still be considered in order to reduce the exposure.

Investigating the Variation of Benzene and 1,3-Butadiene in the UK during 2000-2020

The concentrations of benzene and 1,3-butadiene in urban, suburban, and rural sites of the U.K. were investigated across 20 years (2000-2020) to assess the impacts of pollution control strategies. Given the known toxicity of these pollutants, it is necessary to investigate national long-term trends across a range of site types. We conclude that whilst legislative intervention has been successful in reducing benzene and 1,3-butadiene pollution from vehicular sources, previously overlooked sources must now be considered as they begin to dominate in contribution to ambient pollution. Benzene concentrations in urban areas were found to be ~5-fold greater than those in rural areas, whilst 1,3-butadiene concentrations were up to ~10-fold greater. The seasonal variation of pollutant concentration exhibited a maximum in the winter and a minimum in the summer with summer: winter ratios of 1:2.5 and 1:1.6 for benzene and 1,3-butadiene, respectively. Across the period investigated (2000-2020), the concentrations of benzene decreased by 85% and 1,3-butadiene concentrations by 91%. A notable difference could be seen between the two decades studied (2000-2010, 2010-2020) with a significantly greater drop evident in the first decade than in the second, proving, whilst previously successful, legislative interventions are no longer sufficiently limiting ambient concentrations of these pollutants. The health impacts of these pollutants are discussed, and cancer impact indices were utilized allowing estimation of cancer impacts across the past 20 years for different site types. Those particularly vulnerable to the adverse health effects of benzene and 1,3-butadiene pollution are discussed.

Probabilistic health risk assessment and monetization based on benzene series exposure in newly renovated teaching buildings

To meet the needs of the rapid development of education, there have been growing investments in the issue of university infrastructures. However, few studies have paid attention to the assessment and monetization of health risks in newly renovated teaching buildings. In this study, concentrations of the benzene series (BTEX) group were measured in five areas of three newly renovated teaching buildings. A total of 135 BTEX samples were collected using passive diffusion monitors and analyzed by GC-FID. Human health risk assessments were conducted by using probabilistic methods for four types of population exposure to BTEX. The results showed that the cancer risk of benzene accounted for most of the total in each group. There was over 90% probability of excess cancer risks in the areas within the tested buildings; and the non-cancer risks were all within the acceptable level. The health risks of men were greater than those of women, and those of teachers were higher than those of students. The model calculation results of Disability-Adjusted Life Year (DALY) and Willingness to Pay (WTP) indicated that the average price that society was willing to pay to offset the health damage caused in these newly renovated teaching buildings was 381.35 yuan/year. For the first time, this study highlights the health risks of newly built teaching buildings in universities, points out the urgent need to improve the control of BTEX sources in this type of indoor environment; moreover, it provides theoretical support for the society and occupational protection departments to compensate for the health damage to professionals.

1,3-Butadiene: a ubiquitous environmental mutagen and its associations with diseases

1,3-Butadiene (BD) is a petrochemical manufactured in high volumes. It is a human carcinogen and can induce lymphohematopoietic cancers, particularly leukemia, in occupationally-exposed workers. BD is an air pollutant with the major environmental sources being automobile exhaust and tobacco smoke. It is one of the major constituents and is considered the most carcinogenic compound in cigarette smoke. The BD concentrations in urban areas usually vary between 0.01 and 3.3 μg/m³ but can be significantly higher in some microenvironments. For BD exposure of the general population, microenvironments, particularly indoor microenvironments, are the primary determinant and environmental tobacco smoke is the main contributor. BD has high cancer risk and has been ranked the second or the third in the environmental pollutants monitored in most urban areas, with the cancer risks exceeding 10^-5. Mutagenicity/carcinogenicity of BD is mediated by its genotoxic metabolites but the specific metabolite(s) responsible for the effects in humans have not been determined. BD can be bioactivated to yield three mutagenic epoxide metabolites by cytochrome P450 enzymes, or potentially be biotransformed into a mutagenic chlorohydrin by myeloperoxidase, a peroxidase almost specifically present in neutrophils and monocytes. Several urinary BD biomarkers have been developed, among which N-acetyl-S-(4-hydroxy-2-buten-1-yl)-L-cysteine is the most sensitive and is suitable for biomonitoring BD exposure in the general population. Exposure to BD has been associated with leukemia, cardiovascular disease, and possibly reproductive effects, and may be associated with several cancers, autism, and asthma in children. Collectively, BD is a ubiquitous pollutant that has been associated with a range of adverse health effects and diseases with children being a subpopulation with potentially greater susceptibility. Its adverse effects on human health may have been underestimated and more studies are needed.

Biomarkers of Low-Level Environmental Exposure to Benzene and Oxidative DNA Damage in Primary School Children in Sardinia, Italy

Background: The main anthropic sources of exposure to airborne benzene include vehicular traffic, cigarette smoke, and industrial emissions. Methods: To detect early genotoxic effects of environmental exposure to benzene, we monitored environmental, personal, and indoor airborne benzene in children living in an urban area and an area near a petrochemical plant. We also used urinary benzene and S-phenylmercapturic acid (S-PMA) as biomarkers of benzene exposure and urinary 8-hydroxydeoxyguanosine (8-OHdG) as a biomarker of early genotoxic effects. Results: Although always below the European Union limit of 5 μg/m³, airborne benzene levels were more elevated in the indoor, outdoor, and personal samples from the industrial surroundings compared to the urban area (p = 0.026, p = 0.005, and p = 0.001, respectively). Children living in the surroundings of the petrochemical plant had urinary benzene values significantly higher than those from the urban area in both the morning and evening samples (p = 0.01 and p = 0.02, respectively). Results of multiple regression modelling showed that age was a significant predictor of 8-OHdG excretion, independent of the sampling hour. Moreover, at the low exposure level experienced by the children participating in this study, neither personal or indoor airborne benzene level, nor personal monitoring data, affected 8-OHdG excretion. Conclusions: Our results suggest the importance of biological monitoring of low-level environmental exposure and its relation to risk of genotoxic effects among children.

Cancer and non-cancer health risk assessment of occupational exposure to 1,3-butadiene in a petrochemical plant in Iran

1,3-Butadiene is classified as carcinogenic to humans by inhalation. This study aimed to assess cancer and non-cancer risk following occupational exposure to 1,3-butadiene. This cross-sectional study was conducted in a petrochemical plant producing acrylonitrile butadiene styrene copolymer in Iran. Occupational exposure to 1,3-butadiene was measured according to the National Institute for Occupational Safety and Health 1024 method. Cancer and non-cancer risk assessment were performed according to the United States Environmental Protection Agency method. The average occupational exposure to 1,3-butadiene during work shifts among all participants was 560.82 ± 811.36 µg m^-3. The average lifetime cancer risk (LCR) in the present study was 2.71 × 10^-3; 82.2% of all exposed workers were within the definite carcinogenic risk level. Also, the mean non-cancer risk (hazard quotient (HQ)) among all participants was 10.82 ± 14.76. The highest LCR and HQ were observed in the safety and fire-fighting station workers with values of 7.75 × 10^-3 and 36.57, respectively. The findings revealed that values of carcinogenic and noncarcinogenic risk in the majority of participants were within the definitive and unacceptable risk levels. Therefore, corrective measures are necessary to protect these workers from non-cancer and cancer risks from 1,3-butadiene exposure.

Evaluation of pulmonary function and respiratory symptoms among workers exposed to 1,3-Butadiene in a petrochemical industry in Iran

This study aimed to evaluate pulmonary function among workers exposed to 1,3-butadiene and was carried out in a petrochemical industry in Iran. The study participants consisted of fifty male workers with current respiratory exposure to 1,3-butadiene and fifty non-exposed workers as the control group. Exposure to 1,3-butadiene was measured according to the NIOSH 1024 method. Respiratory symptom histories were collected through the American Thoracic Society respiratory symptom questionnaire. Lung functions were evaluated using spirometry method. The results showed that exposed participants had significantly higher prevalence rates of all respiratory symptoms compared to the control group. Statistical tests demonstrated a significant difference between pulmonary function tests of exposed and non-exposed personnel. Ultimately, the results of the present study indicate that respiratory exposure to 1,3-butadiene can lead to negative effects on pulmonary functions.

Case study of occupational mercury exposure during decontamination of turnaround in refinery plant

Decontamination during turnaround (TA) can lead to high exposure to toxic chemicals among workers. The decontamination process in refinery plants usually comprises two types, i.e. steam and chemical decontamination. No matter the method used, concentrations of toxic chemicals must be measured using the direct reading instrument at the end of each decontamination cycle, which maybe repeated several times until the readings are in acceptable level. To evaluate mercury exposure of decontamination workers during decontamination procedure in comprehensive turnaround of a refinery plant. Thirty personal and 16 area air samples were collected using passive dosimeters and absorbent tubes, respectively, during 8 days of the decontamination in comprehensive turnaround. All samples were analyzed using inductively coupled plasma mass spectrometry (ICP-MS). Good practices and standard procedures for air sampling and analysis were performed. The TWA concentrations were calculated and compared between steam and chemical decontamination workers. All area samples were well below TLV (ND - 0.0016 mg/m³) while 5 of 14 samples collected at the steam team and 1 of 16 samples taken from the chemical team exceeded the TLV. The geometric mean (GSD) of TWA concentration of the steam team was 0.0057(10.4906) mg/m³, which is about twice as high as that of the chemical team, 0.0031(6.9422) mg/m³. The highest mercury concentration, 0.1037 mg/m³, was collected from a steam decontamination worker. According to the activities and observation, the steam team may have high exposure while reading the chemical concentrations at the end of the decontamination cycle.

Low personal exposure to benzene and 1,3-butadiene in the Swedish petroleum refinery industry

PURPOSE

Petroleum refinery workers are exposed to the carcinogens benzene and 1,3-butadiene. Declining exposures have been reported internationally but information on current exposure in the Swedish refinery industry is limited. The aim was to examine refinery workers' personal exposure to benzene and 1,3-butadiene and increase awareness of exposure conditions by collaboration with involved refineries.

METHODS

Altogether 505 repeated personal exposure measurements were performed among workers at two refineries. Full-shift measurements were conducted in different exposure groups using Perkin Elmer diffusive samplers filled with Carbopack X. Mean levels were calculated using mixed-effects models. A large fraction of measurements below the limit of detection (LOD) required imputation of computer-generated data.

RESULTS

Mean benzene exposure among process technicians was 15.3 µg/m3 (95% CI 10.4-22.5 µg/m3) and 13.7 µg/m3 (95% CI 8.3-22.7 µg/m3) for Refinery 1 and 2, respectively. Process technicians working outdoors had higher exposure than maintenance workers (20.7 versus 5.9 µg/m3, p < 0.01). Working in the harbour and tank park (Refinery 1), compared with the process area, was associated with higher exposure. The 1,3-butadiene exposure was low, 5.4 and 1.8 µg/m3, respectively. The total variation was generally attributed to within-worker variability.

CONCLUSIONS

Low benzene and 1,3-butadiene levels were found among refinery workers. Mean benzene exposure was about 1% of the Swedish occupational limit (1500 µg/m3) and for 1,3-butadiene, exposure was even lower. A large fraction of values below the LOD can be managed by carefully modelled, computer-generated data.