Hospitalisations among seafarers on merchant ships.
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AIMS: To study morbidity among active seafarers in the merchant navy in order to clarify possible work related morbidity and the morbidity related to work and lifestyle where possible preventive measures may be initiated. METHODS: From a register in the Danish Maritime Authority a cohort of Danish merchant seafarers who had been actively employed at sea in 1995 was identified. For each seafarer, information on all employment periods at sea, charge aboard, and ship was available. The cohort was linked with the National In-patient Register in Denmark. Standardised hospitalisation ratios (SHRs) were calculated for all major diagnostic groups using all gainfully employed as reference. RESULTS: Seafarers were shown to be inhomogeneous, with significant differences in SHRs for the same disease groups between different groups of seafarers depending on charge and ship type. SHRs for lifestyle related diseases were high, although rates for acute conditions, such as acute myocardial infarction, were low, probably due to referral bias, as acute conditions are likely to cause hospitalisation abroad, and thus are not included in the study. SHRs for injury and poisoning were high, especially for ratings and officers aboard small ships. CONCLUSION: Despite pre-employment selection, a large proportion of the seafarers constitute a group of workers with evidence of poor health probably caused by lifestyle. The subgroups with high risk of hospitalisation due to lifestyle related diseases also had an increased risk of hospitalisation due to injury and poisoning. (+info)
Detection of multiple enteric virus strains within a foodborne outbreak of gastroenteritis: an indication of the source of contamination.
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An outbreak of acute gastroenteritis of suspected viral aetiology occurred in April 2003 in the British Royal Fleet Auxiliary ship (RFA) Argus deployed in the Northern Arabian Gulf. There were 37 cases amongst a crew of 400 personnel. Of 13 samples examined from cases amongst the crew, six enteric viruses were detected by reverse transcriptase polymerase chain reaction (RT-PCR). Five different viruses were identified including, three norovirus genotypes, a sapovirus and a rotavirus. No multiple infections were detected. A common food source was implicated in the outbreak and epidemiological analysis showed a statistically significant association with salad as the source of the outbreak, with a relative risk of 3.41 (95% confidence interval of 1.7-6.81) of eating salad on a particular date prior to the onset of symptoms. Faecal contamination of the salad at source was the most probable explanation for the diversity of viruses detected and characterized. (+info)
Differential shuffling of native genetic diversity across introduced regions in a brown alga: aquaculture vs. maritime traffic effects.
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Worldwide marine invaders, such as the brown alga Undaria pinnatifida, offer challenging models for unraveling the apparent paradox of sustainable settlement of exotic species over a large spectrum of environments. Two intergenic noncoding mitochondrial loci were found to be highly informative at the within-species level. Twenty-five haplotypes were found over the whole dataset (333 base pairs, 524 individuals, and 24 populations). The native range showed striking population genetic structure stemming from low diversity within and high differentiation among populations, a pattern not observed in the introduced range of this seaweed. Contrary to classical expectations of founding effects associated with accidental introduction of exotic species, most of the introduced populations showed high genetic diversity. At the regional scale, genetic diversity and sequence divergence showed contrasting patterns in the two main areas of introduction (Europe and Australasia), suggesting different processes of introduction in the two regions. Gene genealogy analyses point to aquaculture as a major vector of introduction and spread in Europe but implicate maritime traffic in promoting recurrent migration events from the native range to Australasia. The multiplicity of processes and genetic signatures associated with the successful invasion confirms that multiple facets of global change, e.g., aquaculture practices, alteration of habitats, and increased traffic, act in synergy at the worldwide level, facilitating successful pandemic introductions. (+info)
Subjective assessments of safety, exposure to chemicals and use of personal protection equipment in seafaring.
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BACKGROUND: Most of the scientific publications from the maritime area are studies about the mortality and morbidity, while studies about the present hazards of potentially dangerous exposures are relatively rare. AIMS: To describe the seafarers' assessments of the occupational safety on board, their exposure to chemicals and the use of personal protection equipment and to identify the areas for further risk assessment and preventive measures. METHODS: A questionnaire study was carried out in 11 countries among seafarers who attended a regular health examination. RESULTS: The total number of seafarers who participated in the study was 6461 (response rate 93.7%). The occupational safety on board was assessed to be very good or good in 82%. Multivariate analyses showed that the safety was assessed as lowest among ratings, seafarers<30 years of age, work in the engine rooms and on dry cargo ships. It was highest on crude oil tankers and supply ships. Fifty-five per cent of seafarers were exposed to chemicals. Personal protection equipment to chemicals was used 'always/almost always' in 93% of the exposed. Multivariate analysis showed that the use of personal protection was highest on deck, on the largest ships, on roll-on roll-off ships and on crude oil tankers. CONCLUSION: The occupational safety and the use of personal protective equipment was assessed to be significantly different in some strata of the population and in specific working areas and types and sizes of ships. (+info)
Supply-side invasion ecology: characterizing propagule pressure in coastal ecosystems.
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The observed rates and deleterious impacts of biological invasions have caused significant alarm in recent years, driving efforts to reduce the risk (establishment) of new introductions. Characterizing the supply of propagules is key to understanding invasion risk and developing effective management strategies. In coastal ecosystems, ships' ballast water is an important transfer mechanism (vector) for marine and freshwater species. Commercial ships exhibit a high degree of variation in ballast water operations that affect both the quantity and quality of propagule supply, and thereby invasion risk. The per-ship inoculation size from ballast water depends upon both the volume discharged and the organism density. Moreover, propagule quality will vary among source regions (ports) and voyage routes, due to differences in species composition and transport conditions, respectively. We show that significant differences exist in (i) the frequency and volume of ballast water discharge among vessel types, (ii) the frequency of vessel types and routes (source regions) among recipient ports, and (iii) the transit success (survivorship) of zooplankton in ballast tanks among voyage routes. Thus, propagule supply is not a simple function of total ship arrivals. For ships, as well as other vectors, variation in propagule quantity and quality must be explicitly considered to estimate invasion risk and advance predictive ability. (+info)
Ten-year follow-up of blood lead levels with medical removal protection of shipyard workers.
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This cases report compared the short-term changes of BLL with medical removal intervention and follow-up the long-term changes of BLL afterward. During a physical examination in October 1992, a 44-year old shipyard welder was discovered to have a blood lead level (BLL) of 54.1 microg/dl. It was recommended that the shipyard remove this worker from his workplace. In 1993 the BLLs checked for this worker were 36.7 microg/dl in March and 32.0 microg/dl in April. After six months of medical removal, he returned to initial welding work. In 2002, we collected two blood samples from this worker for analysis in May and October. The results were 30.4 microg/dl and 31.6 microg/dl, respectively. Meanwhile, two other welding workers (case 2 and case 3) with BLLs over 40 microg/dl in the survey conducted at the same shipyard in 1992. It took 4 yr to let BLLs downed to less than 40 microg/dl. However, after the blood lead concentration drops to below 40 microg/dl, 10 yr long-term observation indicates that BLLs reduction level off and do not continue to go down in these three cases. (+info)
Sulfur accumulation in the timbers of King Henry VIII's warship Mary Rose: a pathway in the sulfur cycle of conservation concern.
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In marine-archaeological oak timbers of the Mary Rose large amounts of reduced sulfur compounds abound in lignin-rich parts such as the middle lamella between the cell walls, mostly as thiols and disulfides, whereas iron sulfides and elemental sulfur occur in separate particles. Synchrotron-based x-ray microspectroscopy was used to reveal this environmentally significant accumulation of organosulfur compounds in waterlogged wood. The total concentration of sulfur in reduced forms is approximately 1 mass % throughout the timbers, whereas iron fluctuates up to several mass %. Conservation methods are being developed aiming to control acid-forming oxidation processes by removing the reactive iron sulfides and stabilizing the organosulfur compounds. (+info)
Variation of health status among people living on boats in Hue, Vietnam.
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OBJECTIVES: To examine patterns of disease and injury in people living on boats in Hue City, Vietnam, and their relations to socioeconomic conditions, sanitary practices, disease prevention proficiency, and people's preference to continued living on boats. METHODS: The subjects were 3737 people aged 5 years and over living on boats in Hue City, Vietnam. Diseases and injuries were diagnosed according to ICD-10. The associations between disease/injury and socioeconomic conditions, sanitary practices, disease prevention proficiency, and preference to continued living on boats were analysed by logistic regression. MAIN RESULTS: The prevalence rates of certain infectious and parasitic diseases, diseases of the respiratory system, diseases of the skin and subcutaneous tissue, diseases of the digestive system, and injuries were 85.3%, 78.0%, 51.2%, 15.4%, and 13.2%, respectively. Various associations were seen between diseases/injuries and socioeconomic conditions. Patterns of disease were strongly influenced by sanitary practices. Better disease prevention proficiency was significantly related to lower prevalence of the first three categories of diseases/injuries regardless of sex, age, or socioeconomic status (p < 0.05, p < 0.001, p < 0.001, respectively). Diseases were more prevalent among people who preferred not to continue living on boats. CONCLUSIONS: This large scale comprehensive field study illustrated major diseases and injuries among people living on boats. Variations in health status showed a web-like relation of socioeconomic conditions, sanitary practices, disease prevention proficiency, and preference to continued living on boats. Measures to develop disease prevention proficiency reduce the risk of disease and injury. (+info)