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Introduction: Increased rates of leukaemia have been found among tanker crews. Occupational exposures to the leukomogen benzene during loading, unloading, and tank cleaning are possible causes. Studies on older types of tankers carrying gasoline with most handling being done manually have revealed important exposures to benzene. Our study explores benzene exposures on tankers with both automatic and manual systems. Correlations between benzene exposure and benzene in alveolar air (AlvBe), benzene in urine (UBe), and trans,trans-muconic acid (ttMA) in urine were investigated., Methods: Forty-three male seafarers (22 deck crewmembers and 21 not on deck) on five Swedish different product and chemical tankers transporting 95- or 98-octane gasoline were investigated between 1995 and 1998. The tankers used closed systems for the loading and unloading of gasoline but stripping and tank cleaning were done manually. Benzene in respiratory air was measured using personal passive dosimeters during a 4-h work shift. Samples for biomarker analyses were collected pre- and post-shift. Smoking did occur and crewmembers did not use any respiratory protection during work., Results: The average 4-h benzene exposure level for exposed was 0.45 mg m-3 and for non-exposed 0.02 mg m-3. Benzene exposure varied with type of work (range 0.02-143 mg m-3). AlvBe, UBe, and ttMA were significantly higher in post-shift samples among exposed and correlated with exposure level (r = 0.89, 0.74, and 0.57, respectively). Smoking did not change the level of significance among exposed., Discussion: Benzene in alveolar air, unmetabolized benzene, and ttMA in urine are potential biomarkers for occupational benzene exposure. Biomarkers were detectable in non-exposed, suggesting benzene exposure even for other work categories on board tankers. Work on tankers carrying gasoline with more or less closed handling of the cargo may still lead to significant benzene exposure for deck crewmembers, and even exceed the Swedish Occupational Exposure Limit (OEL; 8-h time-weighted average [TWA]) of 1.5 mg m-3., (© The Author(s) 2019. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.)

Objective: The deck crew on tankers can be exposed to high concentrations of benzene and other chemicals during loading, unloading and tank-cleaning operations. The objective of this study was to investigate whether genotoxic or other early health effects of cargo vapour exposure could be detected in coastal tanker crews., Methods: The association between exposure to cargo vapours and clinical symptoms and signs, spirometry, blood cell count, blood test for liver function, and the frequency of micronuclei and sister chromatid exchanges in peripheral lymphocytes was studied in a cross-sectional investigation of 107 male crew members (66 deck crew and 41 others) on ten coastal tankers., Results: Seven of the tankers had automatic cargo level gauging systems but some of the ships still had open hatches during loading and unloading operations. Acute symptoms such as headache, nausea, vertigo, fatigue and dizziness after loading or tank-cleaning operations were reported by 56 of the 66 deck crew members (85%). Irritation of the mucous membrane in eyes and upper respiratory tract by cargo vapours were also common in this group. Obstructive symptoms were more common in the group with the highest exposure to cargo vapours but persistent effects on lung function (vital capacity and forced expiratory volume in 1 s), nervous system, liver enzymes or blood counts were not found. The frequency of micronuclei after mitotic stimulation with phytohaemagglutinin was higher among the deck crew (mean 4.2 SEM 0.40) than in other crew members (mean 3.6, SEM 0.35). although the difference was not statistically significant. We found no association between exposure and the frequency of sister chromatid exchanges or micronuclei after stimulation with pokeweed mitogen., Conclusion: This study indicates that exposure to cargo vapours in coastal tanker crews may cause symptoms in the respiratory and nervous systems.

To study genotoxic effects of exposure to low levels of benzene, single-strand breaks (SSB) in DNA of leukocytes and urinary levels of the oxidative DNA adduct 8-hydroxydeoxyguanosine (8OHdG) were determined in 33 men occupationally exposed to benzene from gasoline and in 33 controls. The average exposure to benzene over a shift was determined by personal air sampling in the breathing zone. The 8-hr time-weighted average exposure to benzene was 0.13 ppm (mean value, range 0.003-0.6 ppm). Exposed workers had a significant increase of SSB (p = 0.04) over the shift compared with controls. Storage time of the samples seemed to affect the results. An analysis of samples with the same storage time showed a nonsignificant increase among the workers compared with controls. Urinary 8OHdG increased over the shift among the exposed workers but not among the controls. The highest values among the exposed workers were seen in late evening, with a slight decrease the next morning. Multiple linear analysis adjusting for smoking habits showed a significant association between the exposure level of benzene during the shift and the increase of 8OHdG in the urine over the shift among exposed workers (p = 0.02). These findings indicate a genotoxic effect in humans of benzene at relatively low exposure levels, that is, about 0.1 ppm (0.3 mg/m3).

A simple and reliable field method is presented for sampling and analysis of benzene in end-exhaled air. The sample is collected directly on an adsorbent tube while the subject exhales through a sampling device consisting of a modified peak expiratory flow meter. To ensure sampling of end-exhaled air, the temperature of the breath is monitored during expiration. The analytes subsequently are thermally desorbed and analyzed by gas chromatography. No sample preparation before analysis is needed, and therefore sample loss is minimized, shipping is easy, storage is possible, and clean up is unnecessary. All these steps have been major problems in earlier methods for breath analysis. The presented method has been applied to the monitoring of benzene. The separation of benzene from other components of exhaled air was good and the detection limit low (0.5 microgram/m3), and therefore benzene could be monitored in occupationally nonexposed nonsmokers. No carry-over in the sampling device or breakthrough could be detected. The samples were stable for at least a week. The combined precision in sampling and analysis was excellent, with a coefficient of variation of 13%.

Deck officers on coastal tankers may be exposed to high concentrations of cargo vapors during loading and tank-cleaning operations. Two cases of acute nonlymphatic leukemia are described. Both men had worked as chief officers on coastal tankers transporting benzene and other petroleum products.

Objectives: To estimate the risk of cancer due to occupational exposure to petroleum products in the Swedish transport and refinery industries.Methods: In a retrospective cohort study the cancer incidence in 4128 men and 191 women, who had worked for at least one year in the petroleum industry, was compared with the incidence in the general population. The job titles and employment times for each person were found in personal files in the industries. The men had on average worked in jobs exposed to petroleum for 11.6 years at the end of the observation period. The cases of cancer were identified by record linkage with the Swedish cancer register.Results: In total there were 146 cases of cancer v 157.6 expected (standardised mortality ratio (SMR) 0.93 90% confidence interval (90% CI) 0.80 to 1.1). Operators at refineries had an increased risk of leukaemia (6 cases v 1.7 expected, 90% CI of relative risk (RR) 1.5 to 7.0). Five of the six cases had started to work at the refineries in the 1950s or later. No other significantly increased risk of cancer was found. Distribution workers had a decreased incidence of lung cancer (no cases, 90% CI of RR 0 to 0.4).Conclusions: Operators at Swedish refineries had an increased risk of leukaemia. A possible cause is exposure to benzene. There was no increased risk of leukaemia in distribution workers. Distribution workers had a decreased risk of lung cancer. [ABSTRACT FROM AUTHOR]