Quality of life--the effect of hyperbaric oxygen treatment on radiation injury.

The purpose of the present study was to assess changes in health-related quality of life (HRQL) among patients with radiation injury one year after hyperbaric oxygen (HBO2 therapy). HBO2 therapy was given once daily, five times a week in monoplace hyperbaric chambers for at least 19 days. HRQL was measured by SF-36 (Short Form with 36 questions). The study population was 101 patients, and among these 53.5% had radiation injury to the head and neck region, 35.6% to the intestine and 10.9% to the bladder. Testing for differences before and one year after HBO2 therapy showed significant improvement for the following SF-36 scales: Physical Function an increase of 4.54 (p = 0.01). Role Performance an increase of 8.79 (p = 0.04). Vitality an increase of 6.88 (p = 0.001). Social Function an increase of 8.04 (p = 0.002). Time since radiation at HBO2 therapy was 1-39 years. A total of 82% received radiation more than one year ago, and 33% more than seven years ago. Changes in physical and mental sum scores were not associated with time since radiation. Patients below the age of 70 seemed to have the best effect of HBO2 therapy measured by HRQL.

Airway symptoms and lung function in the local population after the oil tank explosion in Gulen, Norway.

BACKGROUND: Oil tanks containing a mixture of hydrocarbons, including sulphuric compounds, exploded and caught fire in an industrial harbour. This study assesses airway symptoms and lung function in the nearby population 1½ years after the explosion. METHODS: A cross-sectional study included individuals ≥18 years old. Individuals living <6 km (sub-groups <3km and 3-6 km) from the accident site formed the exposed group, individuals living >20 km away formed a control group. A questionnaire and spirometry tests were completed by 223 exposed individuals (response rate men 70%, women 75%) and 179 control individuals (response rate men 51%, women 65%). Regression analyses included adjustment for smoking, occupational exposure, atopy, infection in the preceding month and age. Analyses of symptoms were also adjusted for stress reactions related to the accident. RESULTS: Exposed individuals experienced significantly more blocked nose (odds ratio 1.7 [95% confidence interval 1.0, 2.8]), rhinorrhoea (1.6 [1.1, 3.3]), nose irritation (3.4 [2.0, 5.9]), sore throat (3.1 [1.8, 5.5]), morning cough (3.5 [2.0, 5.5]), daily cough (2.2 [1.4, 3.7]), cough >3 months a year (2.9 [1.5, 5.3]) and cough with phlegm (1.9 [1.2, 3.1]) than control individuals. A significantly increasing trend was found for nose symptoms and cough, depending on the proximity of home address to explosion site (daily cough, 3-6km 1.8 [1.0, 3.1], <3km 3.0 [1.7, 6.4]). Lung function measurements were significantly lower in the exposed group than in the control group, FEV1 adjusted mean difference -123 mL [95% confidence interval -232, -14]), FEV1% predicted -2.5 [-5.5, 0.5], FVC -173 mL [- 297, -50], FVC% predicted -3.1 [- 5.9, -0.4], and airway obstruction (GOLD II/III). CONCLUSIONS: Based on cross sectional analyses, individuals living in an area with air pollution from an oil tank explosion had more airway symptoms and lower lung function than a control group 1½ years after the incident.

Clinical characteristics of patients with drug hypersensitivity in Norway: a single-centre study.

BACKGROUND: Drug hypersensitivity reactions (DHRs) represent an important public health problem. Knowledge of their clinical characteristics will provide improved diagnostic approaches to this topic. OBJECTIVES: The aim of the present study was to describe the clinical characteristics of patients with suspected DHRs. METHODS: The medical records of 206 outpatients with suspected DHRs, who consulted a Norwegian allergy centre from January 2005 to December 2009, were investigated in a retrospective study. RESULTS: Mean age (range) was 44.3 (11-84) years, and 72% of the patients were women. The most common underlying diseases justifying the use of drugs were infections (49%) and pain-related diseases (23%). Antibiotics (53%), non-steroidal anti-inflammatory drugs (NSAIDs) (32%), paracetamol (15%) and other drugs (46%), used as monotherapy or combinations, were the most often suspected drugs. Cutaneous symptoms were the most frequently reported symptoms (83%). Hospitalisation or prolonged hospitalisation was needed in 38% of the cases, and anaphylaxis was reported in 28% of all the patients. Skin prick tests were performed in 185 patients, of which 14 patients had positive test results. Drug provocation tests (DPTs) were performed in only 86 patients, six of which had positive reactions. DHRs were confirmed in 24 and rejected in 81 patients. Unsettled cases (39%) were mainly due to not performing DPTs. CONCLUSIONS: Suspected DHRs occur predominantly in women. The most common manifestations are cutaneous symptoms, but life-threatening reactions justifying hospitalisation may occur. Antibiotics and NSAIDs are the two drug families most frequently suspected. DPTs need to be included in diagnostic protocols in order to evaluate suspected DHRs.

Risk of misclassification of decompression sickness.

Decompression sickness (DCS) is classified on the basis of which organ system is affected, and neurological DCS is considered more severe than DCS in joints and skin with respect to response to recompression treatment and risk of long-term sequelae. Gas bubble formation interstitially in the tissues or in the circulation is considered to be the mechanism for all types of DCS. Ten patients diagnosed as having DCS in joints or skin, by doctors experienced in diving medicine, underwent clinical examination by a neurologist and had an electroencephalogram. Eight of the ten subjects had findings suggesting central nervous system deficits. The findings indicate that DCS of the central nervous system often accompanies DCS of the joints and skin, and that local skin and joint symptoms may draw attention away from cerebral symptoms. We recommend that all cases with DCS should initially be treated as neurological DCS.

Cerebral diffusion and perfusion deficits in North Sea divers.

BACKGROUND: Diving is associated with a risk of cerebral decompression illness, and the prevalence of neurological symptoms is higher in divers compared with control groups. Microvascular dysfunction due to gas microembolism and exposure to hyperoxia are possible mechanisms, which may result in cerebral diffusion and perfusion deficits. PURPOSE: To investigate if possible functional derangements of the microvasculature and microstructure would be more prevalent among symptomatic divers. MATERIAL AND METHODS: Magnetic resonance imaging (MRI) was performed in 91 former divers and 45 controls. Individual parametric images of apparent diffusion coefficient (ADC), cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) were generated on the basis of diffusion- and perfusion-weighted imaging. To identify regions with statistically significant differences between groups (P < 0.05, corrected for false discovery rate), voxel-wise ANCOVA analysis was performed for each of the four parametric images. RESULTS: Significant regional group differences were found in all four parametric comparisons. Gross regional ADC differences were seen throughout the brain, including large frontal and temporal white-matter regions, the hippocampus, and parts of the cerebellum. Differences in the perfusion maps were localized in fewer and smaller clusters, including parts of the cerebellum, the putamen, and the anterior watershed regions. CONCLUSION: Regional functional abnormalities as measured by diffusion- and perfusion-weighted imaging were identified in the divers, and there was a partial co-localization of the regions identified in the perfusion and the diffusion images. The findings may explain some of the long-term clinical symptoms reported among professional divers.

Occupational allergy to Artemia fish fry feed in aquaculture.

BACKGROUND: Artemia (brine shrimp) is used as feed for fish fry and shrimp in aquaculture. Two employees in a Norwegian aquaculture research farm reported having chest symptoms when working in an Artemia hatch room. AIMS: To determine the presence and prevalence of Artemia sensitization at the farm and the extent of any Artemia-related respiratory and hand skin symptoms and to identify the allergens involved. METHODS: Participants completed a questionnaire and structured interview. Skin prick tests (SPTs) were performed, and immunoglobulin E (IgE) antibodies to Artemia, shrimp and recombinant tropomyosin were determined. Gel electrophoresis and immunoblots of Artemia extracts were also carried out. RESULTS: Thirty of 42 employees (71%) participated. Among the 24 subjects exposed to Artemia, four (17%) reported chest and/or hand skin symptoms during exposure and three of them were IgE sensitized to Artemia. Five (21%) of those exposed demonstrated IgE antibodies to Artemia and four (17%) had immediate-positive SPTs. A serum pool from these subjects exhibited IgE binding to a protein of approximately 97 kDa in the Artemia extract. CONCLUSIONS: Occupational exposure to the Artemia fish fry feed can cause IgE sensitization and allergic symptoms affecting airways and skin.

Musculoskeletal complaints among professional divers.

BACKGROUND: Previous publications have indicated a high risk of musculoskeletal complaints among professional divers. This study aims to investigate which factors influence professional divers' risk of musculoskeletal complaints. MATERIALS AND METHODS: Based on data gathered from a postal questionnaire sent to Norwegian inshore divers in 2011, the prevalence of musculoskeletal complaints, strain injuries and joint pain among divers with different certification levels, work-related tasks and decompression sickness (DCS) experiences were analysed. RESULTS: The risk of musculoskeletal complaints, strain injuries and joint pain was significantly higher among divers working in the quay/construction industry versus divers not working in this industry, and among divers who had experienced DCS. Likewise, a higher risk was found among divers doing construction, inspection, pipelaying, blasting and welding, other physically demanding work, and working with vibrating and/or rotating tools. Having experienced tingling and/or numbness in fingers after working with vibrating and/or rotating tools or having sick leave due to tendonitis, periosteum inflammation, stretch injuries or sprains caused by diving also increased the risk. CONCLUSIONS: Professional divers working in the quay/construction industry, divers doing tasks with heavy physical demands and divers having experienced DCS are at a higher risk of musculoskeletal complaints than other professional divers.

Bronchial responsiveness in bakery workers: relation to airway symptoms, IgE sensitization, nasal indices of inflammation, flour dust exposure and smoking.

BACKGROUND: Bronchial hyperresponsiveness (BHR) is common in bakery workers. The relation between bronchial responsiveness measured with a tidal breathing method and smoking, airway symptoms, IgE-sensitization, nasal indices of inflammation and flour dust exposure have been studied with bronchial responsiveness expressed as a continuous outcome. MATERIAL AND METHODS: Bakery workers (n = 197) were subjected to interviews, questionnaires, allergy tests, workplace dust measurements and bronchial metacholine provocation. Eosinophil cationic protein (ECP) and alpha(2)-macroglobulin were measured in nasal lavage. Bronchial responsiveness was expressed as slope(conc), a measurement based on regressing the per cent reduction in FEV(1) at each provocation step. RESULTS: BHR expressed as slope(conc) was associated with smoking (P = 0.009), asthma symptoms at work (P = 0.001), and occupational IgE sensitization (P = 0.048). After adjusting for baseline lung function the association between BHR and IgE sensitization was no longer present. We demonstrated an association between nasal ECP and BHR (slope(conc) < 3: P = 0.012), but not to alpha(2)-macroglobulin in nasal lavage. No association was seen between BHR and current exposure level of flour dust, number of working years in a bakery or a history of dough-making. CONCLUSION: BHR is related to baseline lung function, work-related asthma symptoms, smoking and nasal eosinophil activity, but not to occupational IgE sensitization and current flour dust exposure when measured with metacholine provocation. The slope(conc) expression seems to be a useful continuous outcome in bronchial responsiveness testing.

Nasal indices of eosinophilic and exudative inflammation in bakery-workers.

AIMS: Rhinitis symptoms frequently occur in bakery-workers. Yet, little is known about the pathophysiology of this condition. The objective of the present study was to examine nasal indices of inflammation in relation to occupational dust exposure, occupational rhinitis according to defined criteria, rhinitis symptoms associated to the workplace, and occupational sensitization in bakery-workers. METHODS: Bakery-workers (n = 197) were subjected to interviews, questionnaires, workplace dust measurements, allergy tests, and nasal lavages with and without histamine. alpha(2)-Macroglobulin and eosinophil cationic protein (ECP) were measured in saline lavages as indices of plasma exudation and eosinophilic activity, respectively. Histamine lavages were employed to explore the nasal exudative responsiveness. RESULTS: alpha(2)-Macroglobulin and ECP increased significantly by increased workplace dust exposure (P< or =0.035). Furthermore, the exudative responsiveness to histamine increased significantly by such exposure (P< or =0.016). Similar patterns were seen in workers with occupational rhinitis and in subjects with rhinitis symptoms associated to the workplace, but not in workers with occupational sensitization. CONCLUSIONS: We conclude that occupational dust exposure in bakery-workers is associated with nasal eosinophilic exudative inflammation. In contrast, occupational sensitization is not a discriminating factor with regard to indices of eosinophilic, exudative inflammation in the present material.

Vestibular symptoms and otoneurological findings in retired offshore divers.

INTRODUCTION: Inner ear barotraumas and decompression sickness (DCS) may cause acute vestibular symptoms in divers. The result may be irreversible damage to the vestibular end organs or their central connections. We examined a group of offshore divers in order to find out how many divers experience vestibular symptoms later in life and how this was related to occupational history and objective findings. METHODS: A questionnaire was sent to 230 offshore divers (mean age 52 yr) and 166 age-matched non-diving controls. Most of the divers had retired from diving. A subgroup (n=96) of the divers was referred for examination, including a clinical otoneurological examination, electronystagmography, bithermal caloric tests, and platform posturography. In addition, 42 of the controls were examined. RESULTS: The prevalence of dizziness (28%), spinning vertigo (14%), and unsteady gait (25%) was significantly higher in divers than controls (p < 0.0005). These symptoms were strongly associated with a previous history of DCS, particularly type I, which was reported by 61% of the divers. Symptoms were less strongly associated with the number of dives. In referred divers with dizziness, the prevalence of abnormal postural sway, nystagmus, canal paresis, or pathological smooth pursuit was 32%, 9%, 7%, and 11%, respectively. DISCUSSION: Reasons for the high prevalence of vestibular symptoms among the divers are discussed. The high exposure to DCS is probably an important factor.

Seafarers' wives and intermittent husbands-social and psychological impact of a subgroup of Norwegian seafarers' work schedule on their families.

OBJECTIVE: To examine the psycho-social impact of work schedules (absence from home) on the families of a subgroup of Norwegian seafarers as reported by their wives (sea wives). Their husbands worked 4-6 weeks on and 4-6 weeks off Norwegian-registered multipurpose vessels (MPV) supporting the off-shore oil industry. METHODS: Questionnaires addressing demographic characteristics, marital satisfaction, social support, subjective health and psychological well-being were distributed to sea wives and controls. The response rate was 57% (192/336) for sea wives and 39% (45/114) for controls RESULTS: There was no difference in demographic characteristics between sea wives and controls except that the sea wives were younger (p<0.01). No differences between sea wives and controls were found with regard to the quality of marital relationships, the subjective evaluation of own health, or mental well-being. Two percent of sea wives and controls had scores suggesting severe depression. In some respects, the sea wives had less social support than the controls. However, the majority of sea wives were content with their families' life style. CONCLUSIONS: The MPV seafarers' absence from home in a 4 weeks on and 4 weeks off (or a 6 weeks on and 6 weeks off) rotation schedule appears to be well tolerated by their families. However, being alone for weeks at the time may exaggerate acute and chronic shore-side problems, and some sea wives may feel a need for more social support during their husbands' absence.

Female professional divers. Similarities and differences between male and female professional divers.

BACKGROUND: The aim of the present study was to explore the potential differences between female and male professional divers with regards to demographics, diving certificates, areas of diving, diving activity and health effects. MATERIALS AND METHODS: The Norwegian Labour Inspection Authority's Diving certificate register contains data on all professional inshore divers who have held a certificate at any time since 1980. Forty nine per cent of these divers responded to the "Norwegian diver 2011" questionnaire. RESULTS: Of these divers 64 female and 1327 male divers completed the questionnaire about their professional diving career, certificate, year of onset and the year they stopped diving professionally if they were not still active in the diving industry. The level of general education was higher among female divers. More males than females were fully certified in diving. The mean age was lower among female than male fully certified divers. Fully certified female divers reported a lower total number of dives, shallower dives and diving for a shorter period of time than the male divers. They also had a lower percentage of work within the quay/construction sector and more often worked as teachers/instructors. A lower percentage of fully certified females than males had experienced decompression sickness (16.7% vs. 26.9%). Life-threatening events and psychologically challenging events were less common among females, as were adverse health effects. No such gender differences were seen for divers with a restricted certificate. CONCLUSIONS: The fully certified, female professional divers in our study had a very short diving career, reported fewer and shallower dives, and chose less physically demanding jobs than their male counterparts. They also had a higher level of education, reported less health problems and a better quality of life. The health effects seem to be related to the type of work rather than to gender.

Diving exposure and health effects in divers working in different areas of professional diving.

BACKGROUND: The aim of the present study was to compare diving exposure and health effects in different areas of professional diving. MATERIALS AND METHODS: The Norwegian Labour Inspection Authority's Diving Register contains data on all professional inshore divers who have held a diving certificate at any time since 1980. Of these divers, the "Norwegian diver 2011" questionnaire was completed by 2848 (48.7%). A total of 1167 male divers reported that they often worked in one area of diving only (rescue diving, diving instruction, fish farming, quay/construction work and offshore/oil related). In the analysis of these divers, rescue divers were used as referents as they reported the lowest number of dives. RESULTS: Age distribution, the proportion of retired divers and the mean number of dives completed varied between the different areas of professional diving. Compared to rescue divers, divers in fish farming, quay/ /construction work and offshore/oil related work more often experienced physically demanding diving. Divers in fish farming more often had no day off after 3 days of physically demanding work compared to rescue divers. All groups except offshore divers reported making further dives after one physically demanding dive on the same day. All groups reported more frequent decompression sickness than did the referents and divers in quay/construction and offshore/oil related diving reported more frequent episodes of unconsciousness during diving than did the referents. Divers in fish farming, in quay/construction work and oil/ /offshore related diving obtained a higher symptom score than the referents and the two latter groups also reported more frequent adverse health effects due to diving than the referents. Health related physical and mental component summary scores were lower in all other groups than in referents. CONCLUSIONS: Compared to the rescue divers, divers in quay/construction work and offshore/oil related divers reported more adverse health effects and obtained a higher symptom score.

Occupational rhinitis: diagnostic criteria, relation to lower airway symptoms and IgE sensitization in bakery workers.

CONCLUSIONS: The use of different diagnostic criteria has considerable consequences for the prevalence estimates of occupational rhinitis. There is a strong relationship between occupational rhinitis and lower airway symptoms. Storage mites appear to be important occupational allergens in Norwegian bakeries. OBJECTIVES: To study the consequences of various diagnostic criteria on the prevalence of occupational rhinitis, assess the prevalence of IgE sensitization and explore the relationships between upper and lower airway symptoms and between symptoms and IgE sensitization. MATERIAL AND METHODS: A total of 197 employees in 6 bakeries were interviewed and completed a questionnaire. A skin prick test was performed, total and specific IgE were determined and a histamine release test was performed for relevant allergens. The criteria for the diagnosis of occupational rhinitis were based on the 1994 International Consensus Report on Rhinitis. RESULTS: The prevalence of occupational rhinitis varied between 23% and 50%, depending on the criteria used. The occurrence of nasal symptoms was found to precede the development of lower airway symptoms. Occupational rhinitis, both IgE- and non-IgE-mediated, was associated with asthma symptoms. The most frequent causes of sensitization (20%) were different species of storage mites. Storage mite sensitization was related to occupational rhinitis and work exposure.

Mortality among retired offshore divers in Norway.

BACKGROUND: Health effects of diving have been observed in divers who have not experienced any diving related accidents. The aim of the study was to study total, and cause specific mortality, in Norwegian retired professional offshore divers. MATERIALS AND METHODS: We carried out a mortality follow-up from 1997 to 2013 in a group of men, born 1930-1973. The diving cohort consisted of 386 male professional divers diving in the North Sea in the pioneer period from 1965 to 1990, of which 25 were dead. 1,467,769 Norwegian males were used as referents. This population was linked to the Norwegian Cause of Death Registry. RESULTS: Twenty five (6.5%) professional offshore divers had died. No differences were observed between divers and referents for overall mortality or for non-violent deaths, adjusted for year of birth. CONCLUSIONS: In this cohort of retired North Sea divers, the mortality pattern did not differ from that of the expected mortality.

Pregnancy outcome among offspring of airline pilots and cabin attendants.

OBJECTIVES: This study assessed the occurrence of perinatal death, low birthweight, preterm birth, and birth defects (total, major, neural tube defects, total cleft, cleft palate, hypospadias, and Down syndrome) in the offspring of airline pilots and cabin attendants. METHODS: A cohort of offspring of airline pilots and cabin attendants was established and characterized in terms of parental exposure to cosmic radiation the year before birth or ever. Pregnancy outcome was derived from the Medical Birth Register of Norway. The reference group comprised offspring of parents without occupational exposure to cosmic radiation. RESULTS: No deviant risks were observed for the offspring of male pilots, either for the year preceding birth (N=2,111) or ever (N=2,356). Specific birth outcomes were fewer for the pilots than for the referents (N=1,621,186), except for Down syndrome, which was more frequent [odds ratio (OR) 1.41, 95% confidence interval (95% CI) 0.53-3.76]. For exposure the year preceding birth (N=2,512), the risk of low birthweight was lower for the female cabin attendants than for the referents (adjusted OR 0.83, 95% CI 0.69-1.00), while Down syndrome was more frequent (OR 1.44, 95% CI 0.60-3.47). For exposure ever (N=3346), the risk of low birthweight was lower (OR 0.82, 95% CI 0.70-0.96) for the cabin attendants, while hypospadias (OR 1.18, 95% CI 0.61-3.04) and Down syndrome (OR 1.79, 95% CI 0.03-3.45) were more frequent CONCLUSIONS: In general, offspring of air pilots and cabin attendants do not seem to be at increased risk of adverse pregnancy outcome.

Secular trends in uncertain-sex births and proportion of male births in Norway, 1967-1998.

It has been hypothesized that environmental factors influence sex differentiation in the fetus, thus causing a reduced sex ratio (male/female) at birth, an increase in the prevalence of ambiguous-sex infants, and possibly an increase in spontaneous abortion rates. In Norway, subsequent to 1967, all deliveries, including late abortions after 16 wk of gestation, have been reported to the Medical Birth Registry of Norway. The authors used these data to assess birth-weight-specific secular trends of uncertain-sex infants and the proportion of male births, from 1967 through 1998. Total rates of uncertain-sex infants increased from 2.3/10,000 births in 1967 to 8.0/10,000 births in 1998 in the birth weight strata of less than 600 gm. The total proportion of male births was stable; however, there was a reduction in the proportion of male births among births weighing less than 400 gm--from 58.4% to 53.4%. Incomplete ascertainment of abortions may have biased the results, but it would not have accounted for the increased occurrence of uncertain-sex infants and the decreased proportion of males observed among late-term abortions.

Upper limb disability in Norwegian workers with hand-arm vibration syndrome.

BACKGROUND: Hand-arm vibration syndrome (HAVS) is a well-known disease among workers using hand-held vibrating tools. These patients experience major symptoms from their upper limbs. However, there are few studies on disability in this patient group. In this study we wanted to describe the disability of HAVS patients. METHODS: All HAVS patients diagnosed at Haukeland University Hospital in Bergen, Norway in a five-year period were invited. The disabilities of the arm, shoulder and hand (DASH) questionnaire was sent by mail. Clinical data were extracted from their hospital journals. Descriptive statistics and regression analyses were performed. RESULTS: Thirty-eight patients were recruited. Mean DASH score was 41.2, while the mean of a normal population is 10. Ability to perform tasks related to work and everyday life was affected in these patients. We found a significant association between the DASH score, hand grip strength and tendinitis, also after adjustment for age and smoking in pack-years. CONCLUSION: HAVS patients demonstrate a high level of upper limb disability as assessed by the DASH score. Ability to perform tasks related to work and everyday life was affected. We found a significant association between the DASH score, hand grip strength and tendinitis. This should be focused upon in future research.

Cancer risk among professional inshore divers in Norway.

BACKGROUND: Professional divers are exposed to physiological effects of increased ambient pressure and may be exposed to hazards like carcinogens in polluted breathing gas and water. Consequences in terms of adverse health effects and mortality have been debated for many years. AIM: The aim of this study was to compare the risk of cancer in Norwegian professional divers to that of the general population. MATERIALS AND METHODS: All professional divers born 1950-1990 and registered by compulsory notification in The Norwegian Labour Inspection Authority's registry of divers were included and grouped according to the type of diving certificate. By August 2010, 5,526 male divers were identified. The rest of the male population born in the same period (1,591,243) was used as referents. The Cancer Registry of Norway, based on compulsory notification of all diagnosed malignancies, was linked to the Diver Registry. RESULTS: A higher risk of cancer, OR 1.54 (CI 1.21-1.96), was observed among fully certified divers compared to the referents. No excess risk was observed for professional divers with limited certificate. CONCLUSIONS: Norwegian fully certified divers had higher risk of cancer compared to the Norwegian male population. Based on small numbers, the higher risks among divers within subgroups of cancer sites should be interpreted with care.

Prevalence and causes of loss of consciousness in former North Sea occupational divers.

BACKGROUND: Loss of consciousness (LOC) is a serious event during diving. The purpose of this study wasto estimate the prevalence and causes of LOC during diving in former North Sea divers, and the impacton health-related quality of life. MATERIALS AND METHODS: Up to 1990 a total of 373 Norwegian offshore divers worked in the North Sea. From 2000 to 2011, 221 of these were referred to the Department of Occupational Medicine at Haukeland University Hospital for examination due to health complaints. They filled in a questionnaire for registration of diving experience and health complaints, including the SF-36 version 1 for the assessment of quality oflife. The questionnaire and the hospital records were systematically reviewed by 2 independent observers. Episodes of LOC during diving and the causes were registered. All participants underwent a clinical neurological examination. Electroencephalogram (EEG) and the event-related brain potential (P300) were recorded. RESULTS: One or more episodes of LOC were reported by 58 of 219 divers. LOC due to gas cut was reportedby 27 of these. Divers having experienced LOC due to gas cut had lower SF-36 sub-scores then the rest of the diving population. EEG and P300 recordings did not differ between the groups. CONCLUSIONS: A high proportion of former Norwegian North Sea divers reported episodes of LOC, for whichgas cut was the most common cause. Both hypoxia and peritraumatic stress associated with the episodecould have a long term impact on the quality of life. Neurophysiological functions, however, did not differbetween the groups.