Quantitative relationships of perfluoroalkyl acids in drinking water associated with serum concentrations above background in adults living near contamination hotspots in Sweden.

Contaminated drinking water (DW) is a major source of exposure to per- and polyfluoroalkyl substances (PFAS) at locations around PFAS production/use facilities and military airports. This study aimed to investigate quantitative relationships between concentrations in DW and serum of nine perfluoroalkyl acids (PFAAs) in Swedish adult populations living near contamination hotspots. Short-chained (PFPeA, PFHxA, PFHpA, and PFBS) and long-chained PFAAs (PFOA, PFNA, PFDA, PFHxS and PFOS) were measured in DW and serum. We matched DW and serum concentrations for a total of 398 subjects living or working in areas receiving contaminated DW and in one non-contaminated area. Thereafter, linear regression analysis with and without adjustments for co-variates was conducted. This enabled to derive (i) serum concentrations at background exposure (CB) from sources other than local DW exposure (i.e. food, dust and textiles) at 0 ng/L DW concentration, (ii) population-mean PFAA serum:water ratios (SWR) and (iii) PFAA concentrations in DW causing observable elevated serum PFAA concentrations above background variability. Median concentrations of the sum of nine PFAAs ranged between 2.8 and 1790 ng/L in DW and between 7.6 and 96.9 ng/mL in serum. DW concentration was the strongest predictor, resulting in similar unadjusted and adjusted regression coefficients. Mean CB ranged from <0.1 (PFPeA, PFHpA, PFBS) to 5.1 ng/mL (PFOS). Serum concentrations increased significantly with increasing DW concentrations for all PFAAs except for PFPeA with SWRs ranging from <10 (PFHxA, PFHpA and PFBS) to 111 (PFHxS). Observed elevated serum concentrations above background variability were reached at DW concentrations between 24 (PFOA) and 357 ng/L (PFHxA). The unadjusted linear regression predictions agreed well with serum concentrations previously reported in various populations exposed to low and high DW levels of PFOA, PFHxS and PFOS. The quantitative relationships derived herein should be helpful to translate PFAA concentrations in DW to concentrations in serum at the population level.

Cancer incidence in a cohort of Swedish merchant seafarers between 1985 and 2011.

PURPOSE: Lung cancer, mesothelioma and several lifestyle-associated cancer forms have been reported more common in merchant seafarers. However, few studies reflect recent occupational settings and women seafarers are usually too scarce for meaningful analyses. We conducted a study on cancer incidence between 1985 and 2011 in a Swedish cohort consisting of male and female seafarers. METHODS: All seafarers in the Swedish Seafarers' Register with at least one sea service between 1985 and 2011 and a cumulated sea service time of ≥ 30 days (N = 75,745; 64% men, 36% women; 1,245,691 person-years) were linked to the Swedish Cancer Register and followed-up until 31 December 2011. Standardized incidence ratios (SIR) were calculated with the general population as reference. RESULTS: There were 4159 cancer cases in total, with 3221 among men and 938 among women. Male seafarers had an increased risk of total cancer (SIR 1.05; 95% CI 1.01-1.09), lung cancer (SIR 1.51; 95% CI 1.35-1.67) and urinary bladder cancer (SIR 1.17; 95% CI 1.02-1.33). Several lifestyle-associated cancer forms were more common in men. Previous work on tankers was associated with leukaemia (SIR 1.41; 95% CI 1.00-1.86). The risk of cancer decreased with a start as a male seafarer after 1985, with a significant trend for total cancer (P < 0.001), lung cancer (P = 0.001) and, for tanker seafarers, leukaemia (P = 0.045). Women seafarers had an increased risk of lung cancer (SIR 1.54; 95% CI 1.23-1.87) but the risk of total cancer was not increased (SIR 0.83; 95% CI 0.78-0.89). CONCLUSIONS: In this cohort of merchant Swedish seafarers 1985-2011, the risk of total cancer was increased in men but not in women compared to the general population. Lung cancer was increased in both genders. The risk of cancer seems to decrease over the last decades, but better exposure assessments to occupational carcinogens and longer observation times are needed.

Mortality from cardiovascular disease in a cohort of Swedish seafarers.

PURPOSE: The aim of this study was to investigate whether Swedish seafarers have increased mortality from cardiovascular disease compared with the general population. METHODS: Register-based longitudinal cohort study of 85,169 Swedish seafarers where all subjects with a minimum of 30 days service registered in the Seafarers' Register 1985-2013 were included. Mortality from coronary heart disease, cerebrovascular disease and total mortality for comparison were analysed by calculating standardised mortality ratios (SMRs), with 95% confidence intervals (CIs). Mortality was further analysed by gender, duty on board, type of vessel, and over time. RESULTS: There was no increase in either mortality from cardiovascular disease or total mortality for seafarers, who had worked solely on passenger ferries. Mortality from coronary heart disease and cerebrovascular disease was increased for male seafarers < 46 years old who had worked on different types of vessels, SMR 1.48 (95% CI 1.06-2.01) and SMR 1.93 (95% CI 1.16-3.02), respectively. Analysing the seafarers by duty showed significantly increased SMRs from coronary heart disease in males aged < 46 of the categories "deck crew" and "engine officer/crew (ever)". The total mortality for seafarers who had worked on different types of vessels was increased; males SMR 1.05 (95% CI 1.02-1.09) and females SMR 1.17 (95% CI 1.04-1.30), but decreased over time. CONCLUSIONS: No increased mortality on passenger ferries but younger male seafarers on different types of vessels had increased mortality from cardiovascular disease. Reduction of hazardous occupational exposures onboard is important, such as shift work, stress and noise.

Hematologic malignancy in tanker crewmembers: A case-referent study among male Swedish seafarers.

BACKGROUND: Work on Swedish petroleum tankers before the late 1980s has been associated with an increased risk of hematologic malignancy (HM). Since then, ship modernizations have decreased occupational exposure to gases, including the carcinogen benzene. We explored the risk of HMs in Swedish seafarers who had worked on newer types of tankers. METHODS: A case-referent study in male seafarers from a cohort of all Swedish seafarers was set up by record linkage with the Swedish Cancer Registry using the subjects' personal identification number. For each case (N = 315), five referents were randomly chosen from within the cohort, matched by birth year and three different periods of first sea service (<1985, 1985-1991, and ≥1992). Information on the type of ship and dates of service was retrieved from the Swedish Seafarers' Registry. Odds ratios (OR) were calculated by conditional logistic regression together with 95% confidence intervals (CI). RESULTS: The OR of HM was 1.07 (95% CI, 0.80-1.42) for work on tankers. In seafarers that had started to work on tankers ≥1985, the OR was 0.85 (95% CI, 0.50-1.43). For those who started to work on tankers before 1985, the OR was 1.17 (95% CI, 0.84-1.21) and 1.32 (95% CI, 0.86-2.03) if the cumulative time on tankers exceeded 5 years of service. In this last group, the OR of multiple myeloma was 5.39 (95% CI, 1.11-26.1). CONCLUSION: Although limited by crude exposure contrast and a short follow-up, work on tankers after 1985 was not associated with an increased risk of HM among Swedish seafarers.

Work environment and safety climate in the Swedish merchant fleet.

PURPOSE: To get knowledge of the work environment for seafarers sailing under the Swedish flag, in terms of safety climate, ergonomical, chemical and psychosocial exposures, and the seafarers self-rated health and work ability. METHODS: A Web-based questionnaire was sent to all seafarers with a personal e-mail address in the Swedish Maritime Registry (N = 5608). Comparisons were made mainly within the study population, using Student's t test, prevalence odds ratios and logistic regressions with 95% confidence intervals. RESULTS: The response rate was 35% (N = 1972; 10% women, 90% men), with 61% of the respondents working on deck, 31% in the engine room and 7% in the catering/service department (1% not classifiable). Strain on neck, arm or back and heavy lifting were associated with female gender (p = 0.0001) and younger age (below or above 30 years of age, p < 0.0001). Exposures to exhausts, oils and dust were commonly reported. Major work problems were noise, risk of an accident and vibrations from the hull of the ship. The safety climate was high in comparison with that in land-based occupations. One-fourth had experienced personal harassment or bullying during last year of service. CONCLUSIONS: Noise, risk of accidents, hand/arm and whole-body vibrations and psychosocial factors such as harassment were commonly reported work environment problems among seafarers within the Swedish merchant fleet.

Benzene Exposure and Biomarkers in Alveolar Air and Urine Among Deck Crews on Tankers Transporting Gasoline.

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.

Lung cancer and mesothelioma among engine room crew--case reports with risk assessment of previous and ongoing exposure to carcinogens.

OBJECTIVE: The aim of this article is to illustrate, by means of case reports on occupational exposure in four men with cancer, the hazards of previous and ongoing carcinogenic exposures in ships' engine rooms. Several cases of cancer occurred within a few years among the engine room crew of a passenger ferry. An investigation was undertaken to establish the number of cases, the types of cancers involved, and their possible relation to work. SUBJECTS AND METHODS: Nine cases of cancer among crew members of the ferry were reported between 2001 and 2006, six of which occurred in crew working in the engine room. During the investigated time period, 65 men had been employed in the engine room (mean age 40, range 16-65, years). Four cases were referred to our department. Medical history, personal risk factors and specific diagnoses were collected by medical examinations and from the medical files. An experienced occupational hygienist evaluated work-related exposure to carcinogens. RESULTS: Two engine room ratings contracted lung cancer at the age of 54 and 61, respectively. Both men had been smokers for many years (33 and 45 years, respectively). One engine room rating and one electrical engineer were diagnosed with mesothelioma at the age of 61 and 63, respectively. All four had started to work in engine rooms between 1959 and 1967. Carcinogenic exposure included asbestos, with an estimated cumulative exposure of 2-5 fibreyears/mL, as well as polycyclic aromatic hydrocarbons (PAHs) and nitroarenes from oils, soot and engine exhaust. CONCLUSIONS: For the lung cancer cases, smoking and asbestos exposure were considered clear risk factors, and PAHs and nitroarenes possible risk factors. For the mesothelioma cases, former asbestos exposure was considered a causal factor. Asbestos can still be present on ships. Steps should be taken to reduce the exposure to asbestos, PAHs and nitroarenes, and smoking.