Associations between sleep,risk and safety climate: A study of offshore personnel on the Norwegian continental shelf

The demands and constraints of the offshore working environment can have adverse effects on health, particularly the quality of sleep. Perceived risk and safety are significant psychological stress factors which may interfere with and deteriorate the sleep quality of offshore personnel. The present study explores the relationship between risk perception, safety climate and sleep quality. Data were collected under the auspices of the Petroleum Safety Authorities in Norway using a cross-sectional design. A total of 9601 offshore workers from 52 offshore installations on the Norwegian continental shelf participated in the study. Our findings indicate that both risk perception and safety climate are significantly related to sleep quality. The results of the present study suggest that risk perception and safety climate not only are important aspects of safety performance in the offshore industry, but also have an impact on sleep quality.     

Residual inorganic soil nitrogen in grass and maize on sandy soil

Nitrogen (N) remaining as inorganic ('mineral') soil N at crop harvest (N(minH)) contributes to nitrate leaching. N(minH) data from 20 (grass) and 78 (maize) experiments were examined to identify main determinants of N(minH). N-rate (A) explained 51% (grass) and 34% (maize) of the variance in N(minH). Best models included in addition crop N-offtake (U), offtake in unfertilised plots (U(0)), and N(minH) in unfertilised plots (N(minH,0)) and then explained up to 75% of variance. At low N-rates where apparent N recovery rho keeps to its initial value rho(ini), N(minH) keeps to its base level N(minH,0). At N-rates that exceed the value A(crit) where rho drops below rho(ini), N(minH) rises above N(minH,0) by an amount proportional to (rho(ini)-rho)A. About 80% of (rho(ini)-rho)A was found as N(minH,) in grass as well as in maize. The fraction (1-rho(ini))A does not appear to contribute to N(minH) at low N-rates (A< or =A(crit)) or at high N-rates (A>A(crit)).     

Sustainable disposal of municipal solid waste: Post bioreactor landfill polishing

Sustainable disposal of municipal solid waste (MSW) requires assurance that contaminant release will be minimized or prevented within a reasonable time frame before the landfill is abandoned so that the risk of contamination release is not passed to future generations. This could be accomplished through waste acceptance criteria such as those established by the European Union (EU) that prohibit land disposal of untreated organic matter. In the EU, mechanical, biological and/or thermal pretreatment of MSW is therefore necessary prior to landfilling which is complicated and costly. In other parts of the world, treatment within highly engineered landfills is under development, known as bioreactor landfills. However, the completed bioreactor landfill still contains material, largely nonbiodegradable carbon and ammonia that may be released to the environment over the long-term. This paper provides a conceptual analysis of an approach to ensure landfill sustainability by the rapid removal of these remaining materials, leachate treatment and recirculation combined with aeration. The analysis in this paper includes a preliminary experimental evaluation using real mature leachate and waste samples, a modeling effort using a simplified mass balance approach and input parameters from real typical bioreactor cases, and a cost estimate for the suggested treatment method.     

Quantification of organotin compounds and determination of imposex in populations of dogwhelks (Nucella lapillus) from Norway

Unintentional effects of the antifouling agent tributyltin (TBT) have been discovered in marine gastropods as the induction of male sex characters in females, known as imposex. The occurrence of imposex in dogwhelks (Nucella lapillus) was investigated in 41 populations sampled in 1993-1995 along the Norwegian coast. A method for quantification of organotin species using gas chromatography and atomic emission detection (GC-AED) was developed. Some degree of imposex occurred in almost all populations of dogwhelks studied, except in four from Northern Norway. The concentration of organotin compounds in the gastropods from the unaffected populations was below the detection limit (7 ng Sn/g d.w.). The concentration of TBT in dogwhelks from affected populations was in the range 48-1096 ng Sn/g d.w. A positive relation between the concentration of TBT in dogwhelks and the degree of imposex was found.     

Radiographic evidence of pulmonary fibrosis and possible etiologic factors at a nickel refinery in Norway

Animal studies have shown that nickel compounds may induce pulmonary fibrosis, but so far only limited documentation in humans has been available. Radiographs of 1046 workers in a nickel refinery in Norway were read blindly and independently by three NIOSH certified B-readers, according to the ILO standards. Pulmonary fibrosis (PF) was defined as a median reading of ILO score > or = 1/0 and following this criterion, 47 cases (4.5%) were identified. In logistic regression models, controlling for age and smoking, there was evidence of increased risk of PF with cumulative exposure to soluble nickel or sulfidic nickel (p = 0.04 for both). For metallic nickel a p-value of 0.07 was found. For soluble nickel there was a dose-response trend for 4 categories of cumulated exposure. In the group with the highest cumulative exposure to soluble nickel (low exposure as reference), the crude odds ratio for PF was 4.34 (95% CI 1.75-10.77). The risk adjusted for age, smoking, asbestos and sulfidic nickel was 2.24 (0.82-6.16), with a dose-response trend. The corresponding figures for sulfidic nickel were 5.06 (1.70-15.09, crude) and 2.04 (0.54-7.70, adjusted for age, smoking, asbestos and soluble nickel). However, the dose-response trend was less clear for sulfidic nickel. Controlling for estimated asbestos exposure at the refinery tended to increase the odds ratios of soluble and sulfidic nickel. This study indicates that in addition to age and smoking exposure to soluble and sulfidic nickel compounds are risk factors of PF in humans. Since the number of cases identified in this study is small and undetected confounders may have been present, further studies in other cohorts are appropriate.     

Early prenatal direct gene diagnosis of cystic fibrosis in a twin pregnancy and subsequent selective termination

We present a case of prenatal diagnosis of cystic fibrosis (CF) in one twin at 11–12 weeks of gestation. The parents had previously had two children, one of whom is alive and healthy and one who died of CF at the age of 2½ months. The parents were both known to be carriers of the ΔF508 mutation. Chorionic villus sampling (CVS) was performed and direct gene analysis showed that one fetus was homozygous for the ΔF508 mutation, while the other fetus did not have the mutation at all. Both fetuses had normal karyotypes. Selective termination was subsequently performed. The pregnancy continued without complications except for mild pre-eclampsia at term. The woman had a Caesarean section. The genetic diagnosis was confirmed after birth.     

Effects of increased sea water concentrations of CO2 on growth of the bivalve Mytilus edulis L

It has been proposed that emission of anthropogenic carbon dioxide to the atmosphere will lead to increased concentrations of CO(2) in sea water corresponding to a decrease of pH of several tenths of pH units. An experiment was performed to test the effects of increased sea water concentrations of CO(2) on shell growth of the blue mussel Mytilus edulis. The experiment was performed in aquaria continuously flushed with sea water spiked with CO(2) to provide five different levels of pH between 6.7 and control sea water with a pH of 8.1. The shell length of the mussels was measured at the start and end of the 44 days experimental period. No mortality was observed during the first 23 days of the experiment. The growth increment in mm was much larger for small mussels than for large mussels, but relative growth profile as function of pH was more similar in the two size groups; observed differences may be random variation between samples. The experiments showed that CO(2) induced reduction of pH affects the growth of M. edulis negatively. There was a strong and statistically significant decrease in growth at the lowest pH values, with virtually no growth at pH = 6.7 and reduced growth at pH = 7.1. The effect seems to set in between pH 7.4 and 7.1; at mean pH levels 7.4 and 7.6 the growth increments were not significantly different from growth at normal pH 8.1.     

Feeding in Arctic darkness: mid-winter diet of the pelagic amphipods Themisto abyssorum and T. libellula

The pelagic amphipods Themisto abyssorum and Themisto libellula represent important links between the herbivore zooplankton community and higher trophic levels of the Arctic marine food webs. Large double structured eyes of both of these hyperiid species are assumed to be used for visual prey detection. However, no information is available on the feeding strategies of these visually searching predators for the period of the polar night, a time of year with no or very low levels of daylight. Here, we report on the stomach and gut content of both Themisto species collected during a January expedition around Svalbard (78° to 81°N). Results indicate that T. abyssorum and T. libellula feed actively during the Arctic winter. The major food source of both amphipods consisted of calanoid copepods, most frequently Calanus finmarchicus.     

Lung cancer incidence among Norwegian nickel-refinery workers 1953-2000

Among workers employed at a nickel refinery in Norway between 1910 and 1977 an elevated risk of lung cancer has been demonstrated. A dose-related effect from nickel exposure has been identified, with the strongest gradient for water-soluble nickel. This pattern was recently confirmed in a nested case-control study with adjustment for smoking and potential occupational confounders. In the present study, updated cancer data were used to explore the risk by duration of work at the refinery and by exposure to different forms of nickel. Comparisons were made with the national male population (standardised incidence ratios) as well as internal reference groups (Poisson regression) under adjustment for age and smoking. The results confirmed earlier findings of a strong dose-related risk dependent on duration of work in production departments and cumulative exposure to nickel, most clearly seen for water-soluble nickel. Only slightly elevated risks were found among the unexposed and in the group with no experience from production or maintenance work. The risk associated with exposure to nickel chloride was similar to that for nickel sulfate. Analyses restricted to men exposed after 1967, with estimates based on personal monitoring of nickel in the breathing zone, showed the same risk pattern as for earlier years. Elevated lung cancer incidence was even suggested for workers with their first employment after 1978 when a lot of high exposure jobs were abandoned. The combined effect of exposure to nickel and smoking seemed to be in agreement with a multiplicative risk pattern.