Biomedical subjects

D Norbäck

Publications and source records attributed to D Norbäck.

At least 55 records · Page 3Linked to original sources

PubMed2000

Acoustic rhinometry in epidemiological studies--nasal reactions in Swedish schools.

A cross-sectional study was performed on the relationships between hygienic measurements and nasal investigations in 234 personnel in 12 primary schools in mid-Sweden. Hygienic data included building characteristics, measurements of indoor air pollutants, air change rate, temperature and humidity. Clinical examinations included symptom reports, acoustic rhinometry and nasal lavage, with the determination of biomarker levels for eosinophil cationic protein (ECP), lysozyme, myeloperoxidase (MPO) and albumin. Subjective nasal obstruction was increased in schools with mechanical ventilation (adjusted prevalence OR = 2.0; 95 CI 1.1-3.7) and subjects reporting nasal obstruction had higher levels of dust in the classroom, compared to those not reporting this symptom (p = 0.008 by Mann-Whitney U-test). Congruently, a decreased nasal patency measured by acoustic rhinometric minimum cross-sectional areas (MCA1 and MCA2) was related to the use of mechanical ventilation (p = 0.008 and p = 0.02 respectively, by Mann-Whitney U-test), dust levels (p = 0.03 and p < 0.001 respectively, by Kendall's tau correlation analysis), a lower cleaning frequency of desks (p < 0.001 and p = 0.02 respectively, by Kendall's tau correlation analysis), the use of wet mopping (p < 0.001 and p = 0.04 respectively, by Mann-Whitney U-test) and PVC floor material (p < 0.001 and p = 0.034 respectively, by Mann-Whitney U-test). The cleaning frequency of floors was positively correlated with MCA1 (p = 0.049 by Kendall's tau correlation analysis). In buildings with signs of water damage, flat roof or a concrete slab fundament the personnel had increased ECP, lysozyme or albumin levels in nasal lavage. A reduced nasal patency and an increased inflammatory biomarker response were seen for higher levels of formaldehyde (MCA1, MCA2, VOL1, VOL2, ECP and lysozyme) and nitrogen dioxide (MCA1, VOL2, ECP and lysozyme) in the classrooms. In conclusion, the results indicate that acoustic rhinometry in combination with the determination of nasal lavage biomarkers can be used to study effects on the upper airways of the indoor environment. Actual exposures to indoor air pollutants in Swedish schools can affect the occurrence of subjective nasal obstruction and give clinical signs of reduced nasal patency together with an inflammatory biomarker response in the nasal mucosa.

Acoustics↗

PubMed2000

Buckwheat allergy and reports on asthma and atopic disorders in Taiyuan City, Northern China.

Allergy to common buckwheat (Fagopyrum esculentum) has been reported from Europe and Japan, and a 24 kDa globulin protein has been identified as one of the major allergens. In China also another type, tartary buckwheat (Fagopyrum tartaricum) is grown and consumed. Three groups of individuals in Shanxi province, China, were investigated for buckwheat allergy using skin prick test. The groups were: agricultural researchers with occupational exposure to buckwheat (N = 16); workers in a food industry producing buckwheat noodles (N = 25), and patients with diabetes or cardiovascular disease consuming buckwheat as functional food (N = 20). Information on atopic disorders and adverse food reactions were collected by a doctors-administered questionnaire. One male industrial worker had a positive skin prick test to buckwheat, but no symptoms while eating or handling buckwheat products. In total, 34% consumed buckwheat food at least every week, and 23% had a weekly consumption of tartary buckwheat. The prevalence of doctor's diagnosed asthma was low (1.6%). Four subjects (6.6%) reported a history of allergic rhinitis, with allergy to cedar pollen, carnation and peach.

Adult↗

PubMed1999

Nasal and ocular symptoms, tear film stability and biomarkers in nasal lavage, in relation to building-dampness and building design in hospitals.

OBJECTIVES: To study the relationships between dampness in concrete floors and building design on the one hand, and symptoms and medical signs of the eyes and nose in hospital workers, on the other. METHODS: Four hospitals for geriatrics were selected to represent buildings with different ages and design, irrespective of symptom prevalence. The first building was built in 1925. The second, built in 1985, was known to have dampness in the floor. Conventional building techniques were used in the third building, built in 1993, and the last building was built in 1994, and was specially designed to include high ceilings, and minimal use of fluorescent lighting and interior plastic materials. The interior surfaces were painted with water-based beeswax glazing. All staff (n=95) working day shifts were invited to take part in a medical examination of the eyes and nose including acoustic rhinometry and nasal lavage, and a medical questionnaire, and 93% participated. Measurements of temperature, relative air humidity, air flow, illumination, volatile organic compounds (VOCs), molds, and bacteria were carried out in all buildings, together with measurements of formaldehyde, respirable dust, carbon monoxide (CO), carbon dioxide (CO(2)), nitrogen dioxide (NO(2)) and ozone. Statistical analyses were performed by bivariate analysis, and linear, ordinal, and logistic multiple regressions, adjusting for age, gender, tobacco smoking, atopy, and the perceived psychosocial work environment. RESULTS: Dampness in the upper concrete floor surface (75-84%), ammonia under the floor [3 parts per million (ppm)], and 2-ethyl-1-hexanol in the air were detected in the two buildings built in 1985 and 1993. Increased occurrences of ocular and nasal symptoms, an increased concentration of lysozyme in nasal lavage, and decreased tear film stability were found in the subjects working in the damp buildings. Those in the specially designed building had fewer ocular and nasal symptoms, and increased tear film stability. All buildings had low levels of formaldehyde, molds, bacteria, ozone, and NO(2). The lowest total concentration of VOCs, and the highest concentration of specific VOCs of microbial origin, were found in the building with special design. CONCLUSION: The study provides new evidence of the role of dampness-related alkaline degradation of di-(2-ethylhexyl) phthalate (DEHP) in polyvinyl chloride (PVC) building material. Emissions related to degradation of DEHP due to dampness in the floor, indicated by increased 2-ethyl-1-hexanol in the air, seem to increase both the secretion of lysozyme from the nasal mucosa and the occurrence of ocular and nasal symptoms. The indoor environment of the specially designed building with high ceilings and no fluorescent lighting or interior plastics seemed to have a positive influence on the nasal and ocular mucous membranes.

Adult↗

PubMed1999

Urinary cotinine concentration in flight attendants, in relation to exposure to environmental tobacco smoke during intercontinental flights.

OBJECTIVES: To measure and compare the urinary cotinine concentration (U-cotinine) in non-smoking cabin attendants (C/A) working with the Scandinavian Airlines System, before and after work on intercontinental flights with exposure to environmental tobacco smoke (ETS). METHODS: The study material consisted of 24 cabin attendants and one pilot, all volunteers and all without exposure to ETS in the home, working on 15 intercontinental flights. Information on age, gender and occupation was gathered, as well as possible sources of ETS exposure in other places, outside work and during previous flights, during a 3-day period prior to the investigation. Urine samples were taken before departure and after landing, on board, and were kept frozen (-20 degrees C) until analysis. Cotinine was analyzed by a previously developed gas chromatographic method, using mass spectrometry (MS) with selected-ion monitoring (SIM). The difference in U-cotinine before and after the flight was compared. Moreover, the change in U-cotinine during the flight was related to occupation (work in the forward or aft galley) and observed degree of smoking during each flight. RESULTS: The median U-cotinine was 3. 71 microg/g crea; 2.4 microg/l (unadjusted) (interquartile range 2. 08-8.67 microg/g crea) before departure, and 6.37 microg/g crea; 7.1 microg/l (interquartile range 3.98-19 microg/g crea) after landing, a significant difference (P < 0.003). C/A in the aft galley had a significantly higher concentration of U-cotinine after landing than subjects working in the front of the aircraft (P=0.01). In C/A working in the aft galley, the median increase of U-cotinine was 3. 67 microg/g crea; 3.2 microg/l (interquartile range 0.04-13.8 microg/g crea) during flight. In contrast, those seven subjects working in the forward part of the aircraft had no increase in U-cotinine during the flight (median increase 0.97 microg/g crea; 0. 5 microg/l interquartile range 0.27-2.65 microg/g crea). CONCLUSION: Tobacco smoking in commercial aircraft may cause significant exposure to environmental tobacco smoke among C/A working in the aft galley, despite high air exchange rates and spatial separation between smokers and non-smokers. This agrees with earlier studies, as well as measurements on the aircraft, showing a higher degree of ETS-related air pollution in the aft galley than in the forward galley. The average cotinine concentration in urine was similar to that in other groups with occupational exposure to ETS, e.g., restaurant staff, police interrogators and office workers. Since smoking in commercial aircraft may result in an involuntary exposure to ETS among non-smokers, it should be avoided.

Adult↗

PubMed1999

Inflammation markers in nasal lavage, and nasal symptoms in relation to relocation to a newly painted building: a longitudinal study.

INTRODUCTION: There is a need to evaluate possible health effects of ventilation improvements and emissions from new buildings, in longitudinal studies. New methods to study biological effects on the eyes and upper airways are now available. MATERIAL AND METHODS: A longitudinal study was performed on 83 trained social workers in two offices in Uppsala, Sweden. The exposed group (n = 57) moved to a newly redecorated building nearby. Low emitting building material had been used, including a new type of solvent-free water-based paint. The control group (n = 26) worked in the same office during the study period (November 1995 to February 1996). Hygiene management was carried out in both offices, at the beginning and the end of the investigation. Tear film stability (BUT) was measured. Nasal patency was measured by acoustic rhinometry, and eosinophilic cationic protein (ECP), myeloperoxidase (MPO), lysozyme and albumin were analyzed in nasal lavage fluid (NAL). RESULTS: The relocation resulted in an increase in the personal outdoor airflow rate from 11 to 22 l/s. Indoor concentrations of terpenes were higher in the new building, and powdering of the new linoleum floor was observed. Measurements showed low levels of volatile organic compounds (VOC), formaldehyde, carbon dioxide (CO(2)), nitrogen dioxide, respirable dust, and microorganisms in the air of all buildings. The move resulted in an increased nasal patency and an increase of ECP and lysozyme in NAL, after adjusting for changes in the control group. No changes were observed for nasal or ocular symptoms. A seasonal effect, with a decrease of ECP, was observed in the control group. CONCLUSSION A well-ventilated office building can be redecorated without any major ocular or nasal effects, or measurable increase of indoor air pollution if low-emitting building materials are selected. In agreement with previous evidence, the improved ventilation flow may explain the increase of nasal patency. The increase of ECP and lysozyme in NAL suggested an inflammatory effect in the new building. Since this building had increased ventilation flow, increased concentrations of terpenes, and powdering from the polish on the new linoleum floor, identification of causative agents was difficult. The hygiene measures did not give any evidence that emissions from the new type of solvent-free water-based paints or building dampness were responsible for the observed nasal effects. Considering the higher emissions of VOC reported from older types of water-based latex paints and solvent-based wall paints, the new type of solvent-free water-based paint seems to be a good choice from the hygiene point of view.

Adult↗

PubMed1999

Asthma-related work disability in Sweden. The impact of workplace exposures.

Work disability due to respiratory disease, especially asthma, is common and costly among working age adults. The goal of this analysis was to characterize the risk factors for such disability. We analyzed data from the Swedish part of the European Community Respiratory Health Survey (ECRHS), a random population-based sample of adults age 20 to 44, enriched with symptomatic subjects at increased likelihood of having asthma. We analyzed structured interview data available for 2,065 subjects and further analyzed methacholine challenge and skin prick test data for 1,562 of these. We defined respiratory work disability as reported job change or work loss due to breathing affected by a job. We used binary generalized linear modeling with a log link to estimate disability risk. Eighty-four subjects (4%) reported such work disability. This increased to 13% among those with asthma (45 of 350 subjects). Adjusting for covariates, occupations at high risk for asthma were associated with disability (prevalence ratio [PR] 1.8; 95% confidence interval [CI] 1.1 to 3.0), as was self-reported regular exposure to environmental tobacco smoke (ETS) at work (PR 1.8; 95% CI 1.1 to 3.1) and self- reported job exposure to vapors, gases, dust, or fumes (VGDF) (PR 4.3; 95% CI 2.2 to 8.6). Workplace ETS exposure was also associated with methacholine challenge-positive asthma reported to be symptomatic at work among male subjects (PR 4. 2; 95% CI 1.8 to 9.8), whereas high asthma-risk occupations were associated with this outcome among female subjects (PR 2.7; 95% CI 1. 05 to 7.1). Respiratory work disability, defined as breathing-related job change due to work loss, was associated with workplace exposures themselves, even after taking into account other covariates. Better control of workplace exposures, including workplace ETS, may reduce work disability caused by respiratory conditions, especially adult asthma.

Adult↗

PubMed1999

Nasal patency and lavage biomarkers in relation to settled dust and cleaning routines in schools.

OBJECTIVES: This study determined the relations between settled dust and cleaning routines in classrooms on one hand, and nasal symptoms, nasal cavity dimensions, and the concentration of selected biomarkers of inflammation in nasal lavage on the other. METHODS: Measurements of settled dust via standardized vacuum cleaning and an investigation of the cleaning routines were performed in 12 randomly selected primary schools in the municipality of Uppsala. Clinical examinations including acoustic rhinometry and nasal lavage were performed in the school environment among 279 school personnel working in the main buildings of the schools. Eosinophil cationic protein (ECP), myeloperoxidase (MPO), lysozyme, and albumin were analyzed in the lavage fluid. The relationships between the medical and hygienic data were analyzed both bivariately and with a multiple regression model controlling for age, gender, smoking, atopy, room temperature, and urban vicinity of the school. RESULTS: The amount of settled dust was positively related to subjective nasal obstruction and smaller nasal cavity dimensions measured with acoustic rhinometry. The noses were less patent, and the levels of ECP or lysozyme in the lavage were increased for the subjects in schools with a lower frequency of floor mopping, a lower frequency of desk cleaning, and where wet mopping was used. CONCLUSIONS: Our results indicate that the actual dust levels in Swedish classrooms can affect the occurrence of nasal obstruction among school personnel. A beneficial effect on the clinical signs of the nasal mucosa was observed for a higher frequency of both floor mopping and desk cleaning, whereas the use of wet mopping seemed disadvantageous in comparison with dry mopping. These findings illustrate the need for adequate cleaning procedures to minimize the environmental effects on the airway mucosa.

Air Pollution, Indoor↗

PubMed1999

Current asthma and biochemical signs of inflammation in relation to building dampness in dwellings.

SETTING: Study of current asthma in adults in relation to the indoor environment. OBJECTIVES: To assess the effect of building dampness in dwellings on the occurrence of current asthma, and biochemical signs of inflammation. DESIGN: A nested case-control study with 98 prevalent cases of asthma and 357 controls, within a stratified random population sample (20-45 years) from the Uppsala, Sweden, part of the European Community Respiratory Health Survey (ECRHS). Current asthma was defined as a combination of bronchial hyperresponsiveness and at least one asthma symptom (wheeze or attacks of breathlessness). Statistical calculations were made by multiple linear or logistic regression, adjusting for age, sex and smoking. RESULTS: Building dampness was found in 27% of dwellings. Current asthma was more common among subjects living in damp dwellings (odds ratio [OR] 1.8; 95% confidence interval [CI] 1.1-3.0), particularly with dampness in the floor construction (OR = 4.6; 95% CI 2.0-10.5). The average forced expiratory flow in one second (FEV1) was lower and peak expiratory flow (PEF) variability was higher in subjects from dwellings with floor dampness, and blood eosinophil count was increased in damp dwellings. No relation was found between immediate type allergy to house dust mites and current asthma or building dampness. Immediate type allergy to moulds (Cladosporium or Alternaria) was more prevalent in damp dwellings (9.3% vs 3.9%), and was related to current asthma (OR = 3.4; 95% CI 1.4-8.5). CONCLUSIONS: Building dampness is common in dwellings in Sweden, and seems to be related to an increase in current asthma and biochemical signs of inflammation. Immediate type allergy to house dust mites does not seem to be the explanation, but immediate type allergy to moulds could explain some of the findings.

Adult↗

PubMed1998

Nasal patency and biomarkers in nasal lavage--the significance of air exchange rate and type of ventilation in schools.

OBJECTIVES: The aim of the present study was to examine the relationships between the ventilation rate and the type of ventilation system, on the one hand, and objective nasal measures, on the other. METHODS: A standardized investigation, including acoustic rhinometry and nasal lavage, was performed in the school environment. All 279 school personnel working in the main buildings of 12 randomly selected primary schools in the municipality of Uppsala were invited, and 234 (84%) participated. The dimensions of the nasal cavity were measured with acoustic rhinometry. Eosinophil cationic protein (ECP), myeloperoxidase (MPO), lysozyme, and albumin were analyzed in the lavage fluid. The air exchange rate and the room temperature were measured in the classrooms. Relationships between nasal symptoms, nasal patency, and the concentration of biomarkers, on the one hand, and the type of ventilation system, the air exchange rate, and the temperature, on the other, were analyzed by both crude bivariate analysis and multiple regression models, controlling for the type of ventilation, the air exchange rate, room temperature, age, gender, smoking, atopy, and the urban vicinity of the school. RESULTS: A lower degree of nasal patency as measured by acoustic rhinometry and increased levels of ECP and lysozyme in nasal lavage were associated with a lower air exchange rate in the schools. Although mechanically ventilated schools had higher air exchange rates, they were associated with more nasal symptoms, and nasal mucosal swelling and with increased lavage levels of ECP and lysozyme as compared with schools with natural ventilation only. In contrast, 12 subjects working in a school with mechanical displacement ventilation had more patent noses and lower levels of inflammatory markers as compared with the personnel in schools with natural ventilation only. CONCLUSION: Our results indicate that both a low air exchange rate and mechanical ventilation systems based on dilution can be associated with reduced nasal patency and an inflammatory biomarker response of the nasal mucosa among school personnel. The only school with sufficient ventilation according to the current Swedish recommendations had a displacement system and the fewest signs of nasal reactions among the personnel.

Albumins↗

PubMed1998

Symptoms related to the sick building syndrome in a general population sample: associations with atopy, bronchial hyper-responsiveness and anxiety.

OBJECTIVE: The sick building syndrome (SBS) is a term mainly applied to irritative symptoms in the eyes, skin and upper airways that are experienced in certain environments. The aim of this study was to investigate the characteristics of subjects from the general population that report SBS-related symptoms. METHODS: The study comprised a randomly selected population of 418 individuals aged 20-45 years. The subjects underwent a structured interview, skin prick tests, a methacholine provocation test and answered two questionnaires respectively assessing psychiatric status and the presence of SBS symptoms. RESULTS: Eighty-seven subjects (21%) reported one or more SBS symptom weekly. Most common were general symptoms reported by 10% of the population. Female sex (odds ratio [OR] = 2.1), atopy (OR = 2.2) and anxiety (OR = 2.6) were significant independent risk factors for reporting at least one SBS-related symptom. Anxiety (OR = 3.2) and depression (OR = 4.4) were significant predictors for general symptoms, while bronchial hyper-responsiveness was a significant predictor for pharyngeal symptoms (dryness in the throat, sore throat and irritating cough) (OR = 5.4). CONCLUSIONS: Sick building symptoms are common in the general population and among women, while atopy and anxiety increase the risk of reporting such symptoms. Psychological factors are mainly related to general symptoms, while bronchial hyperresponsiveness is connected with pharyngeal symptoms.

Adult↗

PubMed1998

Pulmonary reactions after exposure to 3-methylfuran vapour, a fungal metabolite.

A case of obstructive pulmonary reaction with flu-like symptoms after exposure to 3-methylfuran is described. This compound is produced by fungi, and can be found in buildings with mould growth. Previous studies have shown that exposure to the substance might increase the prevalence of respiratory symptoms, and is pneumotoxic to animals at high concentrations.

Air Pollutants↗

PubMed1997

Asthma and the indoor environment: the significance of emission of formaldehyde and volatile organic compounds from newly painted indoor surfaces.

As a part of the worldwide European Community Respiratory Health Survey, possible relations between asthma and emissions from newly painted indoor surfaces were studied. The participants (n = 562) answered a self-administered questionnaire, with questions on symptoms and indoor exposures, including indoor painting, during the last 12 months. The participants also underwent a structured interview, spirometry, peak flow measurements at home (PEF), methacholine provocation test for bronchial hyper-responsiveness (BHR), and skin prick tests. In addition, serum concentration of eosinophilic cationic protein (S-ECP), blood eosinophil count (B-EOS), and total immunoglobulin E (S-IgE) were measured. Current asthma was defined as a combination of BHR and at least one asthma-related symptom (wheezing and attacks of breathlessness). The information gathered on indoor painting was compared with exposure measurements of formaldehyde and volatile organic compounds (VOC) performed in a selected sample of the dwellings (n = 62). Relations between exposures, asthma and clinical signs were calculated by multiple linear or logistic regression, adjusting for possible influence of age, gender and tobacco smoking. The prevalence of asthma was increased among subjects with domestic exposure to newly painted surfaces (OR = 1.5; 95% CI 1.0-2.4), particularly newly painted wood details (OR = 2.3; 95% CI 1.2-4.5) and kitchen painting (OR = 2.2; 95% CI 1.1-4.5). Moreover, blood eosinophil concentrations were significantly elevated among subjects living in newly painted dwellings. A significantly increased prevalence of symptoms related to asthma, but not BHR, was observed in relation to workplace exposure to newly painted surfaces. The indoor concentration of aliphatic compounds (C8-C11), butanols, and 2,2,4-trimethyl 1,3-pentanediol diisobutyrate (TXIB) was significantly elevated in newly painted dwellings. The total indoor VOC was about 100 micrograms/m3 higher in dwellings painted in the last year. A significant increase in formaldehyde concentration was observed in dwellings with newly painted wood details. Our results indicate that exposure to chemical emissions from indoor paint is related to asthma, and that some VOCs may cause inflammatory reactions in the airways. To improve asthma management, and to counteract the increasing frequency of asthma, the significance of the indoor environment should not be neglected. Our study suggests that the contribution of emissions from paint to indoor concentrations of formaldehyde and VOCs should be as low as possible.

Adult↗

PubMed1997

Airway symptoms among house painters in relation to exposure to volatile organic compounds (VOCS)--a longitudinal study.

The increased use of water-based paint (WBP) for indoor application during the last decade has drastically changed the exposure conditions for Swedish house painters. WBP has a lower emission of volatile organic compounds (VOCs) than solvent-based paint (SBP), but contains more reactive compounds, such as biocides, glycol ethers, and other high molecular solvents. The aim of this study was to compare the incidence of airway symptoms and self-reported asthma in house painters with a different degree of use of WBP and SBP. The incidence of seven general airway symptoms, and three work-related symptoms, was analysed by means of a self-administered questionnaire, in a cohort of 207 house painters followed from 1989 to 1992. Different airway symptoms were compared with clinical information obtained by a methacholine challenge test and dynamic spirometry in a selected subgroup of 44 painters. Information on the degree of use of SBP and WBP was used to estimate the total exposure to volatile organic compounds (TVOC) for each individual. In total, 175 men in the cohort worked as painters during the study period. No increase of asthma or respiratory symptoms was observed among those 50 painters with a pure exposure to WBP (estimated TVOC 1-3 mg m-3). Most painters (N = 125) had a mixed exposure to SBP and WBP, the main source of the TVOC being the limited use of SBP. WBP was perceived as less irritative than SBP, but complaints on airway irritation from WBP increased during the study period. The most pronounced increase of airway irritation in relation to both SBP and WBP, was observed among those 35 painters with the highest solvent exposure (estimated TVOC 100-380 mg m-3). An increase of respiratory symptom index and shortness of breath, in relation to estimated TVOC exposure was also observed. Selection effects were detected. Painters leaving their job during the study period had more non-specific hyper-reactivity symptoms, and more airway irritation from WBP, as compared to painters remaining at their occupation. Our study indicates that VOC emissions from SBPs may contribute to the development of respiratory symptoms and airway irritation. We found no increase of respiratory symptoms among painters exposed only to WBPs. There were, however, indications that VOC exposure from WBPs may cause airway irritation in some subjects. Because of selection effects, cross-sectional studies on respiratory symptoms in relation to occupational exposure to paint emissions may be inconclusive.

Adult↗

PubMed1997

Occurrence of Neuropsychiatric Symptoms at Low Levels of Occupational Exposure to Organic Solvents and Relationships to Health, Lifestyle, and Stress.

The objective of this study was to elucidate the effects of alcohol consumption, medical disorders, stressful life events, and solvent exposure on neuropsychiatric symptoms in a population with low levels of occupational exposure to organic solvents. The prevalence of neuropsychiatric symptoms was assessed by Questionnaire 16 (Q16) in 54 miners under notice of dismissal and 124 men in an age-matched random sample from the local population. When the Q16 results were dichotomized at six symptoms (of the 16 possible), regular use of medicine was significantly related to the Q16 score, with an adjusted odds ratio (adjOR) of 4.0, 95% confidence interval (95% CI) 1.2-13. There were also positive relationships to the number of years in work with exposure to organic solvents (adjOR 2.2 per 10 years, 95% CI 1.3-3.8), liters of pure alcohol consumed per month (adjOR 2.8, 95% CI 0.78-10), and unemployment (adjOR 2.4, 95% CI 0.80-7.2). The influences on neuropsychiatric symptoms of various common exposures other than occupational solvent exposure must be considered when questionnaires are used for screening or for studies of possible neurotoxic effects in solvent-exposed workers.

Journal Article↗

PubMed1997

Nasal congestion in relation to low air exchange rate in schools. Evaluation by acoustic rhinometry.

Upper airway symptoms are common, but there is little information available on clinical findings in relation to indoor air pollution. This pilot study was conducted to test whether increased levels of indoor air pollutants in schools may correlate to a swelling of the nasal mucosa. The assumption was made that the degree of swelling could be related to the degree of decongestive effect of xylometazoline, and measured by acoustic rhinometry. The study was performed among 15 subjects in a school with low air exchange rate (0.6 air changes/h) and 12 subjects in a school with high air exchange rate (5.2 air changes/h). Hygienic measurements were performed in both schools. Acoustic rhinometry was performed for each individual under standardized forms. Cross-sectional areas and volumes of the nasal cavity were measured before and after decongestion with xylometazoline hydrochloride. Absolute values of the minimal cross-sectional area were lower in the school with poor ventilation. The decongestive effect of xylometazoline was significantly higher in the school with low air exchange, when correction for the influence of age was made. A diminished decongestive effect was seen with increasing age. The exposure measurements showed that indoor concentrations of volatile organic compounds, bacteria and moulds were higher in the school with low ventilation. In conclusion, raised levels of indoor air pollutants due to inadequate ventilation in schools may affect the upper airways and cause a swelling of the nasal mucosa, and acoustic rhinometry could be a useful objective method to measure human nasal reactions to the indoor environment.

Acoustic Stimulation↗

PubMed1997

Asthma among secondary schoolchildren in relation to the school environment.

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.

Adolescent↗

PubMed1996

Local cold exposure of the hands from cryosectioning work in histopathological and toxicological laboratories: signs and symptoms of peripheral neuropathy and Raynaud's phenomenon.

OBJECTIVES: To study relations between cryosectioning work, skin temperature, early signs of neuropathy in the hands, and vasospastic and neurological symptoms. Microtome work is carried out at histological and toxicological laboratories all over the world. It implicates local cold exposure of -20 degrees C on the hands of exposed laboratory technicians. METHODS: Thirty nine laboratory technicians who use microtomes at the preclinical and clinical laboratories at the University of Uppsala, Sweden were studied. An equal number of nonexposed laboratory technicians served as controls, matched for workplace, sex, age, and smoking habits. Information on symptoms, type of work, and personal factors were assessed by means of a self administered questionnaire. Two point discrimination ability was tested, and vibration perception threshholds were measured for both hands by a bio-thesiometer. Also, skin temperature was measured during cryosectioning work in those 15 technicians performing cryosectioning work during the study period. RESULTS: Most laboratory technicians did not use any gloves during cryosectioning work, and direct contact with frozen materials sometimes occurred and resulted in a rapid cooling of the skin. In six of 15 exposed subjects (40%), the mean skin temperature during microtome work was below 20 degrees C. A later rise in skin temperature, due to a compensatory vasodilation, was found in two subjects. The group exposed to cold had signs of early neuropathy on the right hand, indicated both by vibrametry and two point discrimination test. Significant work related differences in clinical signs within the group exposed to cold was also found. No differences between exposed and nonexposed people were found for symptoms of Raynaud's phenomenon, numbness, or musculosceletal complaints. CONCLUSION: Our study shows that cryosectioning laboratory work may cause adverse health effects--for example, peripheral neuropathy--and measures should be taken to protect the hands from the local cold exposure.

Adult↗

PubMed1995

Asthmatic symptoms and indoor levels of micro-organisms and house dust mites.

As a part of a worldwide investigation on the prevalence of respiratory symptoms, we have performed a study on the relationship between the indoor environment and asthma-like symptoms in the population of a central Swedish municipality. The study comprised 88 individuals, aged 20-45 years who underwent a structured interview, spirometry, a methacholine provocation test, skin-prick tests and blood samples for measurements of serum concentrations of eosinophil cationic protein (S-ECP), blood eosinophil count and total immunoglobulin E (S-IgE). In the homes, the room temperature, air humidity, respirable dust, house dust mites (HDM) and airborne micro-organisms were measured. The relative humidity in all the homes was found to be above 33%. HDM were found in 13% of homes. In the homes of the 47 subjects with asthma related symptoms, significantly higher total levels of bacteria and mould (P < 0.05) and a higher proportion of detected HDM (OR = 5.3) was found than in subjects with no asthma related symptoms, after adjustment for age, sex, smoking, indoor temperature and air humidity. HDM were found to be an independent risk factor for asthma related symptoms (OR = 7.9) and nocturnal breathlessness (OR = 6.2) (P < 0.05), while the total level of bacteria was a risk factor for asthma related symptoms and wheezing (P < 0.05). We conclude that although HDM is relatively infrequently found in the homes of central-Sweden, the presence of HDM is related to asthmatic symptoms. A relation between levels of airborne bacteria and asthma related symptoms was also found.

Adult↗