Acute effects of exposure to vapors of 3-methyl-1-butanol in humans.

UNLABELLED: The secondary alcohol 3-methyl-1-butanol (3MB, isoamyl alcohol) is used, for example, as a solvent in a variety of applications and as a fragrance ingredient. It is also one of the microbial volatile organic compounds (MVOCs) found in indoor air. There are little data on acute effects. The aim of the study was to assess the acute effects of 3MB in humans. Thirty healthy volunteers (16 men and 14 women) were exposed in random order to 1 mg/m(3) 3MB or clean air for 2 h at controlled conditions. Ratings with visual analogue scales revealed slightly increased perceptions of eye irritation (P = 0.048, Wilcoxon) and smell (P < 0.0001) compared with control exposure. The other ratings were not significantly affected (irritation in nose and throat, dyspnea, headache, fatigue, dizziness, nausea, and intoxication). No significant exposure-related effects were found in blinking frequency, tear film break-up time, vital staining of the eye, nasal lavage biomarkers, lung function, and nasal swelling. In conclusion, this study suggests that 3MB is not a causative factor for health effects in damp and moldy buildings. PRACTICAL IMPLICATIONS: 3-Methyl-1-butanol (3MB) is one of the most commonly reported MVOCs in damp and moldy buildings and in occupational settings related to agriculture and composting. Our study revealed no irritation effects at 1 mg/m3, a concentration higher than typically found in damp and moldy buildings. Our study thus suggests that 3MB is not a causative factor for health effects in damp and moldy buildings.

Subjective health complaints and psychosocial work environment among university personnel.

BACKGROUND: Questionnaires are often used to study health problems in working populations. An association between self-reported symptoms and psychosocial strain has been suggested, but results from such studies are difficult to interpret, as a gender difference might be present. The knowledge in this area is not clear. AIMS: To compare the prevalence of subjective health symptoms and their relation to psychosocial work strain among men and women in different age groups, all working as university staff. METHODS: A cross-sectional survey was carried out among university personnel. The questionnaire included a subjective health complaint inventory consisting of 29 items about subjective somatic and psychological symptoms experienced during the last 30 days and psychosocial work factors. Regression analyses were performed. RESULTS: In total, 172 (86%) of 201 eligible employees participated. Women had a higher prevalence of musculoskeletal symptoms than men. Significant differences were found between the genders for headaches, neck pain and arm pain. There was a significant relationship between musculoskeletal symptoms and work strain for both genders. This was found for both men and women below 40 years and among men above the age of 40. No significant difference was found between genders regarding pseudoneurological, gastrointestinal, allergic and flu-like symptoms. CONCLUSIONS: More female than male university personnel reported musculoskeletal symptoms. The musculoskeletal symptoms were associated with high work strain in both genders, but, for women, this was limited to employees under the age of 40. The cause of this gender difference is unknown.

Onset of mucosal, dermal, and general symptoms in relation to biomarkers and exposures in the dwelling: a cohort study from 1992 to 2002.

UNLABELLED: We examined the associations between biomarkers of allergy and inflammation, indoor environment in dwellings, and incidence and remission of symptoms included in the sick building syndrome (SBS) and changes in the home environment of 452 adults who were followed from 1992 to 2002 within the Uppsala part of the European Community Respiratory Health Survey (ECRHS). The 10-year incidence (onset) of general, mucosal, and dermal symptoms was 8.5%, 12.7%, and 6.8%, respectively. Dampness or indoor molds at baseline was a predictor of incidence of general (relative risk [RR] = 1.98), mucosal (RR = 2.28), and dermal symptoms (RR = 1.91). Women had higher incidence of general (RR = 1.74) and mucosal symptoms (RR = 1.71). Indoor painting increased the incidence of general symptoms (RR = 1.62). Bronchial responsiveness (BR), eosinophil counts in blood, total IgE and eosinophilic cationic protein (ECP) in serum at baseline were predictors of incidence of SBS. At follow-up, BR, total IgE, and C-reactive protein (CRP ) were associated with increased incidence of SBS. Moreover, subjects with doctor-diagnosed asthma at baseline had a higher incidence of general (RR = 1.65) and mucosal symptoms (RR = 1.97). In conclusion, female gender, dampness or indoor molds, indoor painting, and biomarkers of allergy and inflammation were associated with a higher incidence of SBS symptoms, in particular mucosal symptoms. PRACTICAL IMPLICATIONS: The focus in Sweden on indoor environment issues over the last few decades has resulted in improvements in dwellings, and reduced tobacco smoking, which could be beneficial for public health. Reducing dampness and molds in the dwelling place is another important way of reducing occurrence of SBS symptoms in the general adult population. The association between the incidence of SBS symptoms and clinical biomarkers of allergy and inflammation suggests a common etiology between inflammatory diseases, including asthma, rhinitis, and SBS. Lastly, good agreement between self-reported and clinically diagnosed atopy indicates that questionnaire data on atopy can be used in epidemiological studies.

Can air pollution affect tear film stability? A cross-sectional study in the aftermath of an explosion accident.

BACKGROUND: After an explosion and fire in two tanks containing contaminated oil and sulphur products in a Norwegian industrial harbour in 2007, the surrounding area was polluted. This caused an intense smell, lasting until the waste was removed two years later. The present study reports examinations of tear film break up time among the population. The examinations were carried out because many of the people in the area complained of sore eyes. The purpose of the study was to assess the relationship between living or working close to the polluted area and tear film stability one and a half years after the explosion. METHODS: All persons working or living in an area less than six kilometres from the explosion site were invited to take part in the study together with a similar number of persons matched for age and gender living more than 20 kilometres away. Three groups were established: workers in the explosion area and inhabitants near the explosion area (but not working there) were considered to have been exposed, and inhabitants far away (who did not work in the explosion area) were considered to be unexposed. A total of 734 people were examined, and the response rate was 76 percent. Tear film stability was studied by assessing non-invasive break-up time (NIBUT) using ocular microscopy. In addition Self-reported Break Up Time (SBUT) was assessed by recording the time the subject could keep his or hers eyes open without blinking when watching a fixed point on a wall. Background information was obtained using a questionnaire. Non-parametric Wilcoxon-Mann-Whitney-tests with exact p-values and multiple logistic regression analyses were performed. RESULTS: Both NIBUT and SBUT were shorter among the male exposed workers than among the inhabitants both near and far away from the explosion area. This was also found for SBUT among males in a multiple logistic regression analysis, adjusting for age and smoking. CONCLUSIONS: Reduced tear film stability was found among workers in an area where an explosion accident had occurred.

Respiratory symptoms, perceived air quality and physiological signs in elementary school pupils in relation to displacement and mixing ventilation system: an intervention study.

UNLABELLED: Schools may be poorly ventilated and may contain furry pet allergens, particles and microorganisms. We studied health effects when changing from mixing ceiling ventilation to two types of displacement ventilation, front ventilation system (FVS) and floor master system (FMS). The study included pupils in three elementary school classes (N = 61), all with floor heating. One class received blinded interventions; the two others were unchanged (controls). Ventilation flow and supply air temperature was kept constant. The medical investigation included tear film stability (BUT), nasal patency and a questionnaire containing rating scales. When changing from mixing ventilation to FVS, the pupils (N = 26) perceived better air quality (P = 0.006) and less dyspnoea (P = 0.007) as compared to controls (N = 35), and BUT was improved (P = 0.03). At desk level, mean CO(2) was reduced from 867 to 655 ppm. Formaldehyde and viable bacteria were numerically lower, while total bacteria and molds were higher with displacement ventilation. There was no difference in symptoms or signs when changing from FVS to FMS. Cat (Der p1), dog (Can f1) and horse allergen (Equ cx) were common in air at all conditions. In conclusion, displacement ventilation may have certain positive health effects among pupils, as compared to conventional mixing ceiling systems. PRACTICAL IMPLICATIONS: Displacement ventilation may be a suitable ventilation principle for achieving good indoor environment in classrooms. The type of supply air diffuser does not seem to be of major importance. The combination of floor heating and displacement ventilation can be a useful way of avoiding the previously described problem of thermal discomfort.

Acute effects of exposure to 1 mg/m(3) of vaporized 2-ethyl-1-hexanol in humans.

The objective was to assess acute effects from controlled exposure of volunteers to 2-ethyl-1-hexanol, a volatile organic compound that is often found in indoor air. Sixteen males and fourteen females were in random order exposed to 1 mg/m(3) of vapors of 2-ethyl-1-hexanol or to clean air (control exposure) in an exposure chamber during 2 h at rest. The subjects performed symptom ratings on Visual Analog Scales. During exposure to 2-ethyl-1-hexanol subjective ratings of smell and eye discomfort were minimally but significantly increased. Ratings of nasal irritation, throat irritation, headache, dyspnoea, fatigue, dizziness, nausea, and intoxication were not significantly affected. No exposure-related effects on measurement of blinking frequency by electromyography, measurement of the eye break-up time, vital staining of the eye, nasal lavage biomarkers, transfer tests, spirometric and rhinometric measures were seen. No differences in response were seen between sexes or between atopics and non-atopics. Practical Implications It is important to assess acute effects in volatile organic compounds like 2-ethyl-1-hexanol. 2-ethyl-1-hexanol is often found in indoor air generated by degradation of plastic building materials or in new buildings. There are associations between 2-ethyl-1-hexanol in indoor air and respiratory effects, eye irritation, headache, and blurred vision. A controlled chamber exposure study in acute effects was performed. In conclusion, this study showed weak subjective symptom of irritation in the eyes.

Healthy hire effect, job selection and inhalation exposure among young adults with asthma.

The aim of the present study was to assess whether asthma onset prior to entering the workforce influences whether a person holds a subsequent job with asthma-related inhalation exposures. The data of 19,784 adults from the European Community Respiratory Health Survey were analysed. For each respondent, a current or previously held job was linked to a job exposure matrix assigning high, low or no exposure to dust, gases or fumes. Jobs were also categorised according to the risk of exposures related to occupational asthma. Associations between asthma and subsequent occupational exposures were assessed using logistic regression models, with a random intercept for study centre and fixed adjustment for age, sex, type of study sample and smoking status. Of the respondents, 8% (n = 1,619) reported asthma with onset before completion of full-time education. This population was at decreased risk of having a job with high (odds ratio 0.79; 95% confidence interval 0.68-0.92) or low (0.91; 0.80-1.03) exposure to dust, gases or fumes. The associations were consistent across exposure types (dusts, gases or fumes) and for jobs with a high risk of occupational asthma. Adults with asthma onset prior to entering the workforce may be less likely to hold jobs involving inhalation exposures.

School air quality related to dry cough, rhinitis and nasal patency in children.

Controls for indoor air quality (IAQ) in schools are not usually performed throughout Europe. The aim of this study was to assess the effects of IAQ on respiratory health of schoolchildren living in Norway, Sweden, Denmark, France and Italy. In the cross-sectional European Union-funded HESE (Health Effects of School Environment) Study, particulate matter with a 50% cut-off aerodynamic diameter of 10 microm (PM(10)) and CO(2) levels in a day of normal activity (full classroom) were related to wheezing, dry cough at night and rhinitis in 654 children (10 yrs) and to acoustic rhinometry in 193 children. Schoolchildren exposed to PM(10) >50 microg x m( -3) and CO(2) >1,000 ppm (standards for good IAQ) were 78% and 66%, respectively. All disorders were more prevalent in children from poorly ventilated classrooms. Schoolchildren exposed to CO(2) levels >1,000 ppm showed a significantly higher risk for dry cough (OR 2.99, 95% CI 1.65-5.44) and rhinitis (OR 2.07, 95% CI 1.14-3.73). By two-level (child, classroom) hierarchical analyses, CO(2) was significantly associated with dry cough (OR 1.06, 95% CI 1.00-1.13 per 100 ppm increment) and rhinitis (OR 1.06, 95% CI 1.00-1.11). Nasal patency was significantly lower in schoolchildren exposed to PM( 10) >50 microg x m(-3) than in those exposed to lower levels. A poor IAQ is frequent in European classrooms; it is related to respiratory disturbances and affects nasal patency.

Sick building syndrome in relation to domestic exposure in Sweden--a cohort study from 1991 to 2001.

BACKGROUND: Most studies on sick building syndrome (SBS) are cross-sectional and have dealt with symptoms among office workers. There are very few longitudinal cohort studies and few studies on SBS in relation to domestic exposures. The aim of this study was to investigate changes in SBS symptoms during the follow-up period and also to investigate changes in different types of indoor exposures at home and relate them to SBS symptoms in a population sample of adults from Sweden. We also wanted to investigate if there was any seasonal or regional variation in associations between exposure and SBS. METHODS: A random sample of 1,000 people of the general population in Sweden (1991) was sent a self administered questionnaire. A follow-up questionnaire was sent in 2001. RESULTS: An increased risk for onset of any skin symptoms (risk ratio (RR) 2.32, 1.37-3.93), mucosal symptoms (RR 3.17, 1.69-5.95) or general symptoms (RR 2.18, 1.29-3.70) was found for those who had dampness or moulds in the dwelling during follow-up. In addition people living in damp dwellings had a lower remission of general symptoms and skin symptoms. CONCLUSIONS: Dampness in the dwelling is a risk factor for new onset of SBS symptoms. Focus on indoor environment improvements in dwellings can be beneficial both for the inhabitants and the general population. Reducing dampness in buildings is an important factor for reducing SBS symptoms in the general population.

Symptoms, complaints, ocular and nasal physiological signs in university staff in relation to indoor environment - temperature and gender interactions.

UNLABELLED: Symptoms, signs, perceptions, and objective measures were studied in university buildings. Two problem buildings with a history of dampness and complaints were compared with two control buildings. Health investigations among university staff were performed at the workplace (n = 173) including tear film stability [non-invasive break-up time (NIBUT) and self-reported break-up time (SBUT)], nasal patency (acoustic rhinometry), nasal lavage fluid analysis [NAL: eosinophil cationic protein (ECP), myeloperoxidase (MPO), lysozyme and albumin] and atopy by total serum IgE and IgE antibodies (Phadiatop). Exposure assessment included inspections, thermal and atmospheric climate at 56 points modelled for all work sites. Multiple regressions were applied, controlling for age and gender. Exposure differences between problem buildings and controls were small, and variations between rooms were greater. Workers in the problem buildings had more general and dermal symptoms, but not more objective signs than the others. Adjusted day NIBUT and SBUT increased at higher night air temperatures, with B (95% CI) 0.6 (0.04-1.2) and 1.3 (-0.02 to 2.5), respectively. Higher relative humidity at mean day air temperature <22.1 degrees C was associated with adjusted NIBUT and SBUT, with B (95% CI) 0.16 (0.03-0.29) and 0.37 (-0.01 to 0.75), respectively. Air velocity below recommended winter values and reduced relative humidity in the range of 15-30% were associated with dry air and too low temperature. PRACTICAL IMPLICATIONS: Thermal climate in university buildings may be associated with both perceptions and physiological signs. Reduced night time air temperature, increased difference in air temperature between day and night, and fast changes in air temperature might impair indoor environment. This may have implication for energy-saving policies. It might be difficult to identify the exposure behind, and find the reason why, some buildings are defined as 'problem buildings'.

Perception of cabin air quality in airline crew related to air humidification, on intercontinental flights.

The influence of air humidification in aircraft, on perception of cabin air quality among airline crew (N = 71) was investigated. In-flight investigations were performed in the forward part and in the aft part on eight intercontinental flights with one Boeing 767 individually, equipped with an evaporation humidifier combined with a dehumidifying unit, to reduce accumulation of condensed water in the wall construction. Four flights had the air humidification active when going out, and turned off on the return flight. The four others had the inverse humidification sequence. The sequences were randomized, and double blind. Air humidification increased relative air humidity (RH) by 10% in forward part, and by 3% in aft part of the cabin and in the cockpit. When the humidification device was active, the cabin air was perceived as being less dry (P = 0.008), and fresher (P = 0.002). The mean concentration of viable bacteria (77-108 cfu/m(3)), viable molds (74-84 cfu/m(3)), and respirable particles (1-8 microg/m3) was low, both during humidified and non-humidified flights. On flights with air humidification, there were less particles in the forward part of the aircraft (P = 0.01). In conclusion, RH can be slightly increased by using ceramic evaporation humidifier, without any measurable increase of microorganisms in cabin air. The cabin air quality was perceived as being better with air humidification. PRACTICAL IMPLICATION: Relative air humidity is low (10-20%) during intercontinental flights, and can be increased by using ceramic evaporation humidifier, without any measurable increase of microorganism in cabin air. Air humidification could increase the sensation of better cabin air quality.

Indoor molds, bacteria, microbial volatile organic compounds and plasticizers in schools--associations with asthma and respiratory symptoms in pupils.

UNLABELLED: We investigated asthma and atopy in relation to microbial and plasticizer exposure. Pupils in eight primary schools in Uppsala (Sweden) answered a questionnaire, 1014 (68%) participated. Totally, 7.7% reported doctor-diagnosed asthma, 5.9% current asthma, and 12.2% allergy to pollen/pets. Wheeze was reported by 7.8%, 4.5% reported daytime breathlessness, and 2.0% nocturnal breathlessness. Measurements were performed in 23 classrooms (May-June), 74% had <1000 ppm CO(2) indoors. None had visible mold growth or dampness. Mean total microbial volatile organic compound (MVOC) concentration was 423 ng/m(3) indoors and 123 ng/m(3) outdoors. Indoor concentration of TMPD-MIB (2,2,4-trimethyl-1,3-pentanediol monoisobutyrate, Texanol) and TMPD-DIB (2,2,4-trimethyl-1,3-pentanediol diisobutyrate, TXIB), two common plasticizers, were 0.89 and 1.64 microg/m(3), respectively. MVOC and plasticizer concentration were correlated (r = 0.5; P < 0.01). Mold concentration was 360 cfu/m(3) indoors and 980 cfu/m(3) outdoors. At higher indoor concentrations of total MVOC, nocturnal breathlessness (P < 0.01) and doctor-diagnosed asthma (P < 0.05) were more common. Moreover, there were positive associations between nocturnal breathlessness and 3-methylfuran (P < 0.01), 3-methyl-1-butanol (P < 0.05), dimethyldisulfide (P < 0.01), 2-heptanone (P < 0.01), 1-octen-3-ol (P < 0.05), 3-octanone (P < 0.05), TMPD-MIB (P < 0.05), and TMPD-DIB (P < 0.01). TMPD-DIB was positively associated with wheeze (P < 0.05), daytime breathlessness (P < 0.05), doctor-diagnosed asthma (P < 0.05), and current asthma (P < 0.05). In conclusion, exposure to MVOC and plasticizers at school may be a risk factor for asthmatic symptoms in children. PRACTICAL IMPLICATIONS: Despite generally good ventilation and lack of visible signs of mold growth, we found an association between respiratory symptoms and indoor MVOC concentration. In addition, we found associations between asthmatic symptoms and two common plasticizers. The highest levels of MVOC, TMPD-MIB, and TMPD-DIB were found in two new buildings, suggesting that material emissions should be better controlled. As MVOC and plasticizers concentrations were positively correlated, while indoor viable molds and bacteria were negatively correlated, it is unclear if indoor MVOC is an indicator of microbial exposure. Further studies focusing on health effects of chemical emissions from indoor plastic materials, including PVC-floor coatings, are needed.

Changes of symptoms, tear film stability and eosinophilic cationic protein in nasal lavage fluid after re-exposure to a damp office building with a history of flooding.

UNLABELLED: The aim was to study health effects in office workers (N = 18) in a medical case book archive with dampness caused by flooding. They were first investigated in a building without dampness (exposure free for 10 days). Then all returned to the damp building, and were re-investigated after 2 days. We measured tear film break up time (BUT), nasal patency, biomarkers in nasal lavage (NAL), and dynamic spirometry. Both buildings had low CO(2) (380-600 ppm), low levels of respirable particles (8-10 microg/m(3)), and formaldehyde (5-7 microg/m(3)). The flooded building had slightly higher (149 ng/m(3) vs. 94 ng/m(3)) levels of microbial volatile organic compounds (MVOC). After 2 days of re-exposure, there was an increase of ocular (P < 0.001), nasal (P = 0.002), and throat symptoms (P < 0.001), dyspnea (P = 0.006), headache (P = 0.002), nausea (P = 0.04), and tiredness (P = 0.01). The median BUT decreased from 16 to 8 s (P = 0.003), and eosinophilic cationic protein (ECP) in NAL increased slightly (P = 0.04). A separate test of the weekday effect showed slight improvements, or no change of symptoms and signs from Monday to Wednesday. In conclusion, subjects previously exposed to building dampness had an increase of symptoms, reduced tear film stability, and signs of eosinophilic inflammation in the nasal mucosa after 2 days of re-exposure. PRACTICAL IMPLICATIONS: The study is in agreement with previous cross-sectional studies, suggesting that building dampness may cause mucosal irritation, general symptoms such as headache and tiredness, impaired tear film stability, and eosinophilic inflammation in the airway mucosa. From a preventive point of view, health consequences of water leakage and flooding should not be neglected. The measurements of molds and microbial volatile organic compounds could not identify any obvious exposure contrast between the damp building and the dry control building. This illustrates the limitations of air measurements of microbial exposures in damp buildings.

Pet keeping and dampness in the dwelling: associations with airway infections, symptoms, and physiological signs from the ocular and nasal mucosa.

UNLABELLED: The aim was to utilize data from a study of occupational indoor environments to analyze symptoms and physiological signs in relation to the home environment. A medical investigation was performed at the workplace among university staff (n = 173) from four university buildings in Bergen, in March 2004. Tear film break up time (BUT) was measured by two methods. Nasal patency was measured by acoustic rhinometry. Nasal lavage fluid analysis (NAL) included eosinophilic cationic protein (ECP); myeloperoxidase (MPO), lysozyme and albumin. Atopy was assessed by total serum IgE and specific IgE (Phadiatop). Totally 21%, 21%, 18%, 11%, and 27% had weekly ocular, nasal, facial dermal symptoms, headache and tiredness, respectively, 15% had a damp dwelling, and 20% had a cat or dog. Multiple linear or logistic regressions were applied, controlling for age gender, smoking, and environmental factors. Building dampness was associated with increased NAL-lysozyme (P = 0.02) and an increase of airway infections [odd ratio (OR) = 3.14, P = 0.04]. Pet keeping was associated with difficulties to concentrate (OR = 5.10, P = 0.001), heavy headedness (OR = 4.35, P = 0.004), four more days with tiredness per month (P = 0.04), and less airway infections (OR = 0.32; P = 0.02). In conclusion, pet keeping was associated with more central nervous system (CNS)-symptoms but less airway infections. Dampness in the dwelling may have inflammatory effects on the airway mucosa, possibly mediated via increased infection proneness. PRACTICAL IMPLICATIONS: The main health focus on pet keeping has been allergen exposure. Our study indicates that effects on airway infections and other types of symptoms should also be considered. The findings support the view that measures should be taken to reduce building dampness in dwellings.

Asthma, eczema, and reports on pollen and cat allergy among pupils in Shanxi province, China.

OBJECTIVES: To study self-reported asthma, eczema, and pollen and furry pet allergy among pupils (9-20 years) in Shanxi province, China, in relation to dietary and environmental factors. METHODS: A standardised questionnaire was distributed to pupils in two primary and two secondary schools, one in Taiyuan city (3.0 milj. inhabitants), the others in Qingxu county, a rural area 30 km outside Taiyuan. Totally, 2,116 pupils (90%) participated. RESULTS: Fifty percent were girls, 61% had been growing up on the countryside, 18% lived in Taiyuan now, 1.7% had ever had asthma, 0.8% had doctor's diagnosed asthma, 1.4% pollen allergy, 1.7% cat allergy, and 0% had dog allergy. Multiple logistic regression was applied, controlling for age, gender, diet, indoor exposures, rural childhood, and current urban residency. Girls had less eczema (OR = 0.51; 95%CI 0.28-0.92). Pupils in the city had more eczema (OR = 5.05; 95% CI 1.11-23.3). Those with a rural childhood had less asthma (OR = 0.17; 95% CI 0.05-0.60), eczema (OR = 0.15; 95% CI 0.13-0.66) and pollen/cat allergy (OR = 0.50; 95%CI 0.25-0.99). None of the indoor variables was related to asthma or allergy. Children with frequent fruit consumption had less asthma (OR = 0.40; 95% CI 0.19-0.82) and pollen/cat allergy (OR = 0.49; 95% CI 0.29-0.84). Those with frequent fish consumption had less asthma (OR = 0.32; 95% CI 0.11-0.97). Those with frequent hamburgers consumption had more asthma (OR = 2.05; 95% CI 1.09-3.87) and eczema (OR = 1.85; 95% CI 1.12-3.04). CONCLUSION: Asthma, eczema, and pollen or pet allergy was uncommon, compared with western countries and other areas in China. Pupils with a rural childhood had less asthma and allergy, which is consistent with the "hygiene hypothesis". Fruit and fish consumption may reduce, and fast food consumption may increase the risk for asthma. Finally, the higher prevalence of asthma and eczema among younger children, born in the 1990s, indicates a cohort effect similar to that observed in western countries.

Personal and psychosocial factors and symptoms compatible with sick building syndrome in the Swedish workforce.

A random sample of 1000 subjects (20-65 years of age) received a postal questionnaire regarding sick building syndrome (SBS), including the three-dimensional model of demand-control-support (DCS). The response rate was 70% (n = 695), and 532 were occupationally active. Female gender and atopy were the main predictors of symptoms. Eye symptoms were more common at low social support combined with strained work situation [odds ratio (OR) 2.37], and at high social support combined with active work situation (OR 3.00). Throat symptoms were more common at low social support combined with either passive (OR 1.86) or strained situation (OR 2.42). Tiredness was more common at low social support combined with either passive (OR 2.41), strained (OR 2.25), or active situation (OR 1.87), and at high social support combined with active work situation (OR 1.83). Low social support combined with either passive (P = 0.01) or strained job situation (P = 0.01) was associated with a higher symptom score (SC). The lowest SC was found at a relaxed work situation, irrespective of social support. In conclusion, female gender, low age, asthma, atopy and psychosocial work environment are associated with symptoms. The three-dimensional model can predict symptoms compatible with SBS, but in a more complex way than earlier research indicated. Practical Implications A multi-disciplinary approach, including psychosocial stress factors as well as personal factors such as gender, age, atopy and asthma, and indoor exposures, should be applied in studies on symptoms compatible with sick building syndrome (SBS). Males and females perceive psychosocial work conditions differently, and may react differently to job stressors. The psychosocial work environment can be as important as gender and atopy as a predictor of SBS symptoms.

Obesity and nocturnal gastro-oesophageal reflux are related to onset of asthma and respiratory symptoms.

Several studies have identified obesity as a risk factor for asthma in both children and adults. An increased prevalence of asthma in subjects with gastro-oesophageal reflux (GOR) and obstructive sleep apnoea syndrome has also been reported. The aim of this investigation was to study obesity, nocturnal GOR and snoring as independent risk factors for onset of asthma and respiratory symptoms in a Nordic population. In a 5-10 yr follow-up study of the European Community Respiratory Health Survey in Iceland, Norway, Denmark, Sweden and Estonia, a postal questionnaire was sent to previous respondents. A total of 16,191 participants responded to the questionnaire. Reported onset of asthma, wheeze and night-time symptoms as well as nocturnal GOR and habitual snoring increased in prevalence along with the increase in body mass index (BMI). After adjusting for nocturnal GOR, habitual snoring and other confounders, obesity (BMI >30) remained significantly related to the onset of asthma, wheeze and night-time symptoms. Nocturnal GOR was independently related to the onset of asthma and in addition, both nocturnal GOR and habitual snoring were independently related to onset of wheeze and night-time symptoms. This study adds evidence to an independent relationship between obesity, nocturnal gastro-oesophageal reflux and habitual snoring and the onset of asthma and respiratory symptoms in adults.

Biomarkers and chemosensory irritations.

OBJECTIVES: A literature review on studies in humans, applying physiological methods to monitor environmentally induced reactions in eyes and upper respiratory tract. The focus was on chemical exposures, but other occupational factors and indoor exposures were included. METHODS: Original articles were gathered from Medline until November 2000, combined with peer-reviewed publications from other sources. RESULTS: Ocular methods included measurement of tear film break-up time (BUT), blink frequency, detection of corneal damage, by vital staining, and cells or inflammatory markers in tear fluid. Nasal methods included acoustic rhinometry, rhinostereometry, and nasal peak expiratory flow. In addition, nasal lavage with isotonic sodium chloride solution was applied to measure concentrations of leucocytes, or biomarkers of secretion or inflammation in nasal lavage fluid (NAL). Most occupational studies were on nasal effects of organic or inorganic dust. There were few studies on occupational exposure to organic solvents or chemical irritants. Some studies demonstrated associations between ocular and nasal physiological response and the indoor environment. Finally, there were some exposure-chamber studies on effects of specific volatile organic compounds (VOCs). Little is known about adaptation at repeated ocular or nasal exposure to irritants. CONCLUSION: Physiological measurements can be valuable complements to symptom registration, but there is a need for standardised investigations. There is a lack of studies on ocular and nasal physiological responses in relation to specific chemical compounds. Experimental studies, with repeated exposure and longer follow-up time on biomarkers, are needed. Finally, there is a need for longitudinal epidemiological studies to elucidate if observed effects should be interpreted as variation within normal physiology, or as early signs of impaired ocular and respiratory health.

Experimental exposure to propylene glycol mist in aviation emergency training: acute ocular and respiratory effects.

OBJECTIVES: Propylene glycol (PG) (1-2 propanediol; CAS No 57-55-6) is a low toxicity compound widely used as a food additive, in pharmaceutical preparations, in cosmetics, and in the workplace-for example, water based paints, de-icing fluids, and cooling liquids. Exposure to PG mist may occur from smoke generators in discotheques, theatres, and aviation emergency training. Propylene glycol may cause contact allergy, but there is sparse information on health effects from occupational exposure to PG. METHODS: Non-asthmatic volunteers (n=27) were exposed in an aircraft simulator to PG mist over 1 minute, during realistic training conditions. Geometric mean concentration of PG was 309 mg/m3 (range 176-851 mg/m3), with the highest concentrations in the afternoon. The medical investigation was performed both before and after the exposure (within 15 minutes). It included an estimate of tear film stability break up time, nasal patency by acoustic rhinometry, dynamic spirometry, and a doctor's administered questionnaire on symptoms. RESULTS: After exposure to PG mist for 1 minute tear film stability decreased, ocular and throat symptoms increased, forced expiratory volume in 1 second/forced vital capacity (FEV1/FVC) was slightly reduced, and self rated severity of dyspnoea was slightly increased. No effect was found for nasal patency, vital capacity (VC), FVC, nasal symptoms, dermal symptoms, smell of solvent, or any systemic symptoms. Those exposed to the higher concentrations in the afternoon had a more pronounced increase of throat symptoms, and a more pronounced decrease of tear film stability. In four subjects who reported development of irritative cough during exposure to PG, FEV1 was decreased by 5%, but FEV1 was unchanged among those who did not develop a cough. Those who developed a cough also had an increased perception of mild dyspnoea. CONCLUSION: Short exposure to PG mist from artificial smoke generators may cause acute ocular and upper airway irritation in non-asthmatic subjects. A few may also react with cough and slight airway obstruction.