The aim of this study was to estimate the prevalence of allergic sensitization and possible risk factors in a genetically homogenous Inuit population living under widely differing climatic and cultural conditions. A written questionnaire and skin prick test for 10 aeroallergens were obtained from 1119 adult Greenlanders residing in Denmark, Nuuk (main city in Southern Greenland) and Uummannaq (rural settlement in Northern Greenland). Allergen exposure was assessed by pollen counts, questions on pet keeping and counts of house dust mites in dust samples. The overall prevalence of at least one positive skin prick test was 22.8% in Denmark, 10.6% in Nuuk, and 6.4% in Uummannaq. In Denmark, the total birch pollen counts were 40-1000 times higher compared to Nuuk, whereas the grass pollen count was 13-30 times higher in Denmark compared to Nuuk. Dogs were held indoor with a similar frequency in Denmark and Nuuk, but much less frequently in Uummannaq. In Denmark, house dust mites were found in 72% of house holds (>10/0.1 g dust). Less than 15% of households in Greenland had measurable levels of house dust mites. The prevalence of sensitization to aeroallergens in Inuit Greenlanders differed significantly between Denmark, Nuuk and Uummannaq. These findings correlated with the observed differences in population allergen exposure in the three regions. Furthermore, differences in lifestyle factors such as educational level, stress and ethnic self-identification seemed to be associated with the risk of allergic sensitization in Greenland.
The county of Värmland, Sweden, has shown a high frequency of multiple sclerosis in several investigations. It has been presented in three studies; a period prevalence study in 1925-1934, a mortality study during 1952-1992 and a prevalence investigation in 2002. The aim of this study was to investigate the pattern of industry in this high-risk area for multiple sclerosis. The three investigations were correlated with industry in 1913 and in the 1950s, all analyzed by the Kruskall-Wallis test. Select industries from wood-pulp, paper and iron/mechanical sectors were tested also in whole Sweden. The Spearman rank correlation was used for these data and forestry data in Värmland. In Värmland, industrial data from 1913 revealed that large sawmills were associated with the period prevalence in 1925-1934 and there was a possible correlation with the prevalence for 2002. Wood-pulp factories showed a possible association with the prevalence 1925-1934 and the mortality 1952-1992. Some industries in the 1950s were correlated with the prevalence 2002. Wood and paper industries in Sweden 1913 showed an association with the MS mortality 1952-1992. In summary, data on MS prevalence in Värmland and mortality both in Värmland and all Sweden from the past 100 years suggest an association with wood-related industries in 1913 and in the 1950s, whereas no consistent association was found for other industries.
The assessment of the human risk of mutagens is a constituent of the general assessment of the risk of environment-pollutant chemicals to the population's health. An algorithm of assessing the risk of mutagens is proposed. Stage 1 (hazard identification) is to provide an expert analytical characterization of the mutagenic potential of the chemicals polluting the study object. Stage 2 (hazard characterization) is to analyze the quantitative dependences of the effect of mutagens in gametes and somatic cells of man and mammals. Stage 3 (effect evaluation) is to characterize the sources of pollution and the doses of mutagens affecting the population. Stage 4 (risk characterization) is to calculate the risk of mutagens to the population and individuals.
BACKGROUND: Poor indoor air quality has been suggested to be related to the increase in the prevalence of asthma that has occurred in the western world, especially among children and young persons. Apart from the home, school is the most important indoor environment for children. OBJECTIVES: The aims were to study the prevalence of current asthma among secondary pupils and its relationship to the school environment, but also to personal factors and domestic exposures. METHODS: Data on asthmatic symptoms, other health aspects, and domestic exposures were gathered using a questionnaire which was sent to 762 pupils in the seventh form (13-14 years old) in 11 randomly chosen schools in the county of Uppsala in Sweden. Pupils answering 'yes' to having had asthma diagnosed by a physician, and having had recent asthma attacks, or who used asthma medication were defined as having current asthma. Data on exposures at school were gathered by measurements in 28 classrooms. The relationship between asthma and exposures was analysed by multiple logistic regression. RESULTS: The questionnaire was completed by 627 (82%). Current asthma was found among 40 pupils (6.4%). Current asthma was more common in those who had an atopic disposition, or food allergy, or who had attended a day care centre for several years. Controlling for these factors, current asthma was related to several factors in the school environment. There were more pupils with current asthma in schools that were larger, had more open shelves, lower room temperature, higher relative air humidity, higher concentrations of formaldehyde or other volatile organic compounds, viable moulds or bacteria or more cat allergen in the settled dust. CONCLUSIONS: Although the pupils attended school for a minor part of their time, our study indicates that the quality of the school environment is of importance and may affect asthmatic symptoms.
BACKGROUND: In a previous study inverse associations between asthma and exposure to fungal spores and endotoxins in atopic farmers and positive associations with the same factors in non-atopic farmers were documented. No external reference population had been included. We, therefore, compared this farming population with the general population from an adjacent region. METHODS: Random samples of a farming (n=2,106) and a rural (n=351) and urban (n=727) general population were selected. Atopy was assessed by serum IgE and asthma by questionnaires. RESULTS: The asthma prevalence was 4.0% among farmers, 5.7% in the rural, and 7.6% in the urban population. Atopy was similar (9-10%). Most asthmatics were not atopic, 67-75%. Farmers had asthma less often than the general population OR 0.52 (95% CI 0.36-0.75); both atopic (OR 0.33 (95% CI 0.15-0.69)) and non-atopic asthma (OR 0.60 (95% CI 0.39-0.93)). CONCLUSION: This may indicate a protective effect of the farm environment on asthma but a healthy worker effect may also play a role.
AIMS: Health problems associated with indoor environments have been reported and discussed extensively during the past few decades, not least in Sweden. There is, however, great uncertainty concerning the background prevalence of the symptoms in question. The main objective of the present study was to investigate the prevalence of general, mucosal, and skin symptoms in the Swedish population. METHODS: A survey comprising 3,000 randomly selected Swedes, age 18-64, was carried out. The survey addressed 25 symptoms, principally general, mucosal, and skin symptoms. A number of other areas were covered and individual data registered at Statistics Sweden were added. The response rate was 70% (2,154 cases). RESULTS: The prevalence of symptoms in the Swedish population was found to accord with results in studies based on different kinds of samples. Women reported significantly more single symptoms, as well as sets of symptoms, than men. There was no clear connection between age and symptoms. The prevalence of symptoms was slightly lower among employees compared with non-workers. Office workers did not report symptoms related to "sick building syndrome" (SBS) more frequently than employees not working in offices. SBS symptoms, skin symptoms, and symptoms similar to those reported by individuals with "electric hypersensitivity" were significantly more prevalent among employees with extensive VDU usage. CONCLUSIONS: The prevalence of reported health complaints accords with that which has been found in previous studies. The background prevalence reported here can serve as a reference for further studies. The high prevalence of symptoms among individuals with extensive VDU usage gives cause for further studies.