| 1. |
- Olin, Anna-Carin, 1960, et al.
(author)
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Nitric oxide (NO) in exhaled air after experimental ozone exposure in humans.
- 2001
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In: Respiratory medicine. - : Elsevier BV. - 0954-6111 .- 1532-3064. ; 95:6, s. 491-5
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Journal article (peer-reviewed)abstract
- We hypothesized that ozone, a common air pollutant, potent in producing airway inflammation, would increase the production of exhaled nitric oxide (NO). If so, measurement of exhaled NO could potentially be a valuable tool in population studies of air pollution effects. Eleven healthy non-smoking volunteers were exposed to 0.2 ppm ozone (O3) and filtered air for 2h on two separate occasions. Exhaled NO and nasal NO were measured before and on five occasions following the exposures. Changes in exhaled and nasal NO after ozone exposure were adjusted for changes after air exposure. There was a slight decrease in exhaled NO (-0.6; -3.1-1.2 ppb) (median and 95% confidence interval) and of nasal NO (-57; -173-75 ppb) directly after the ozone exposure. No significant changes in exhaled or nasal NO were however found 6 or 24 h after the exposure. Within the examined group, an O3 exposure level proven to induce an airway inflammation caused no significant changes in exhaled or nasal NO levels. Hence, the current study did not yield support for exhaled NO as a useful marker of ozone-induced oxidative stress and airway inflammation after a single exposure. This contrasts with data for workers exposed to repeated high peaks of ozone. The potential for exhaled NO as a marker of oxidative stress therefore deserves to be further elucidated.
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| 2. |
- Andersson, Eva, 1955, et al.
(author)
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Adult-onset asthma and wheeze among irritant-exposed bleachery workers.
- 2003
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In: American journal of industrial medicine. - : Wiley. - 0271-3586. ; 43:5, s. 532-538
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Journal article (peer-reviewed)abstract
- Background Whether new-onset asthma is associated with irritant exposure is unclear. The aim was to investigate if occupational exposure to irritant gases, especially repeated peak exposure (gassings), increased the risk of obstructive airways disease. Methods Data on airway symptoms and exposure among bleachery (n=101) and paper department workers (n=314) were collected by a questionnaire. Incidence rates and hazard ratios (HR) (Cox regression) were calculated. Non-responders were interviewed by telephone. Results The incidence rate for adult-onset physician-diagnosed asthma among bleachery workers reporting gassings giving rise to respiratory symptoms was 7.6/103 person-years and for those without gassings 2.2/103 person-years, compared to 1.0/103 person-years for paper workers. In a Cox regression model for asthma (n=12), stratified for sex, HR for gassings were 5.6 (95% confidence intervals (CI) 1.6–20), for hay fever 3.0 (95% CI 0.8–11), and for ever smoking 0.7 (95% CI 0.2–2.4). The same model for adult-onset wheeze gave HR of 5.2 (95% CI 2.2–12), 1.7 (95% CI 0.6–5.4), and 1.1 (95% CI 0.5–2.7), respectively. Conclusions Repeated peak exposure to irritant gases, here studied as gassings in the pulp industry, increased the risk for both adult-onset asthma and wheeze.
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| 4. |
- Gunnbjornsdottir, M. I., et al.
(author)
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Obesity and nocturnal gastro-oesophageal reflux are related to onset of asthma and respiratory symptoms
- 2004
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In: Eur Respir J. - : European Respiratory Society (ERS). ; 24:1
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Journal article (peer-reviewed)abstract
- 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.
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| 5. |
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| 6. |
- Hoffman, C. D., et al.
(author)
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Exposure to ozone gases in pulp mills and the onset of rhinitis
- 2004
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In: Scand J Work Environ Health. ; 30:6
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Journal article (peer-reviewed)abstract
- OBJECTIVE: Rhinitis is a common upper respiratory disease influenced by both genetic and environmental factors. It is also accepted that allergic rhinitis may precede asthma, a disease with more serious consequences. The purpose of this study was to determine whether the risk of noninfectious rhinitis is increased after accidental gassings with ozone among bleachery workers in two pulp mills. METHODS: Bleachery workers (N=120) from two Swedish pulp mills using ozone as their bleaching agent were compared with control workers (N=80) not exposed to ozone in two adjacent paper mills. All of the participants were mailed a respiratory questionnaire that included items about asthma, noninfectious rhinitis, self-reported gassings, and smoking. Hazard ratios (HR) were calculated with proportional hazards regression models. RESULTS: The bleachery workers who reported gassings from ozone were found to be at increased risk of noninfectious rhinitis [HR 3.4, 95% confidence interval (95% CI) 1.3-8.7] when compared with control workers. Bleachery workers without self-reported ozone gassings were not at increased risk (HR 0.9, 95% CI 0.3-2.4). CONCLUSION: Acute exposure to high levels of ozone increases the risk of noninfectious rhinitis. This finding supports the view that peak exposures to irritants should be prevented in pulp mills.
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| 7. |
- Olin, Anna-Carin, 1960
(author)
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Exhaled Nitric Oxide in epidemiological and experimental studies
- 2002
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Doctoral thesis (other academic/artistic)abstract
- The overall purpose with this thesis has been to contribute to the assessment of theutility of exhaled nitric oxide (eNO) in epidemiological studies. The specific aims have been toinvestigate whether eNO increases after occupational exposure to high peaks of ozone, or afterexperimental exposure to ozone in ambient concentrations. The aim has also been to seewhether occupational exposure to ozone increases the risk of asthma or rhinitis. A furtherintention has been to examine the association between atopy and exhaled NO. The influence ofintake of nitrate-rich food on exhaled NO was also studied.Two cross-sectional studies of bleachery workers were carried out, where in the first 56bleachery workers and 39 controls were examined and in the second, performed three yearslater, 228 bleachery workers and 63 controls. All were examined with measurements of exhalednitric oxide (eNO), lungfunction, questionnaires and blood samples. How atopy andsensitization were related to eNO and respiratory symptoms among the non-smoking subjectswas also studied. Furthermore eNO was measured after experimental exposure to ozone where11 healthy volunteers were randomly exposed to 200 ppb ozone or filtered air for two hours.eNO was measured before and directly afterwards, as well as six and 24 hours later. The effectof intake of a meal rich in nitrate on the concentration of nitrate in plasma and eNO, wasexamined in 16 healthy volunteers, who had been on a low nitrate diet for three days.There was no difference in eNO between bleachery workers and controls in either of the twostudies. Within the exposed group, those who had reported ozone exposure followed byrespiratory symptoms ( gassings ) had elevated levels of eNO (58.8 vs. 90.0 nL/min, p=0.019).The same was found in the second study, although only four or more gassings were associatedwith increased eNO (0 gassing: 15.7 ppb, 1-3 gassings: 14.1 ppb and >3 gassings 19.2 ppb,p=0.037). In the second study there were significantly increasing prevalences of rhinitis, adultonsetasthma and current asthma symptoms with increasing frequency of gassings. The atopicsubjects without asthma and rhinitis had eNO levels within the range of non-atopic subjects.Among the atopic subjects reporting symptoms of asthma or rhinitis, only those sensitized toperennial allergen had elevated NO levels. No significant changes of eNO were found afterexperimental exposure to ozone, when adjusting for changes of eNO after filtered air. eNO andplasma nitrate levels were increasing significantly up to two hours after the nitrate-rich meal,with a median increase of 47% (range 7-89%). The increase of eNO and plasma nitrate wascorrelated (rs=0.57, p=0.03).To conclude: gassings from ozone seem to be associated with increased prevalence of adultonset asthma, current asthma symptoms and rhinitis. eNO appears to be a marker for airwayinflammation after repeated occupational exposure to ozone, but not after experimentalexposure to ozone in ambient concentrations. Sensitization to perennial allergens and reportedsymptoms of asthma or rhinitis were found to be associated with higher levels of eNO. Intakeof nitrate- rich food may increase the levels of eNO, and should be restricted or noted beforemeasuring eNO.
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| 8. |
- Olin, Anna-Carin, 1960, et al.
(author)
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Exhaled nitric oxide: relation to sensitization and respiratory symptoms.
- 2004
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In: Clinical and experimental allergy : journal of the British Society for Allergy and Clinical Immunology. - : Wiley. - 0954-7894. ; 34:2, s. 221-6
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Journal article (peer-reviewed)abstract
- BACKGROUND: Conflicting data have been presented as to whether nitric oxide (NO) in exhaled air is merely reflecting atopy rather than airway inflammation. OBJECTIVE: To investigate the relationship between exhaled NO (eNO) and nasal NO (nNO), respiratory symptoms, and atopy, in the context of a cross-sectional study of the respiratory health of bleachery workers. METHODS: Two hundred and forty-six non-smoking bleachery and paper-mill workers answered a questionnaire and were examined by measurements of eNO and nNO and spirometry, outside the pollen season. Blood samples were collected and analysed for specific IgE against common aeroallergens (birch, timothy, cat and house dust mite). Atopy was defined as a positive Phadiatop trade mark test. RESULTS: The atopic and the non-atopic subjects without asthma or rhinitis had similar levels of eNO. Subjects reporting asthma or rhinitis who were also sensitized to perennial allergens had higher levels of eNO, whereas those sensitized to only seasonal allergens had similar eNO levels as non-atopic subjects with asthma or rhinitis. In multiple linear regression models adjusted for nNO, eNO was associated with asthma and sensitization to perennial allergens. CONCLUSION: The results indicate that only atopic subjects who have recently been exposed to the relevant allergen have elevated levels of eNO. Atopic subjects who are not being exposed to a relevant allergen or have never experienced symptoms of asthma or rhinitis show normal eNO. These data indicate that eNO relates to airway inflammation in atopic subjects.
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| 9. |
- Olin, Anna-Carin, 1960, et al.
(author)
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Prevalence of asthma and exhaled nitric oxide are increased in bleachery workers exposed to ozone.
- 2004
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In: The European respiratory journal : official journal of the European Society for Clinical Respiratory Physiology. - 0903-1936. ; 23:1, s. 87-92
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Journal article (peer-reviewed)abstract
- The aims of the present study were to determine whether exposure to high peaks of ozone resulted in an increased prevalence of asthma or respiratory symptoms among bleachery workers and whether nitric oxide (NO) was elevated in the exhaled air of these workers. Bleachery workers (n=228) from three Swedish pulp mills who had been exposed to ozone, together with 63 unexposed control subjects, were investigated by means of spirometry, Phadiatop, exhaled and nasal NO and answers to a questionnaire concerning respiratory symptoms and exposure. Exposure to an ozone peak that gave rise to respiratory symptoms was defined as a "gassing". Bleachery workers reporting four or more gassings involving ozone had an increased prevalence of adult-onset asthma, wheeze, and current asthma symptoms. They also had a higher median concentration of exhaled NO in comparison with those who reported no such gassings (19.2 versus 15.7 parts per billion). No such associations were found in respect of nasal NO. The results from this study show that bleachery workers who have been repeatedly exposed to ozone gassings have an increased prevalence of adult-onset asthma. The results also indicate exhaled nitric oxide may be a marker of airway inflammation in bleachery workers who have been exposed to high peaks of ozone.
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| 10. |
- Olin, Anna-Carin, 1960, et al.
(author)
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Respiratory health among bleachery workers exposed to ozone and chlorine dioxide
- 2002
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In: Scand J Work Environ Health. ; 28:2
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Journal article (peer-reviewed)abstract
- OBJECTIVES: This study investigated the possibility of occupational exposure to ozone increasing the risk of obstructive airway disease among bleachery workers. : Bleachery workers (N = 129) from two Swedish pulp mills using ozone for bleaching were studied together with referents (N = 80) from adjacent paper mills. The pulp mills had previously used chlorine dioxide as the bleaching agent. Testings included spirometry, methacholine challenge testing, and questionnaires. Area samplings showed sporadic ozone levels exceeding 0.9 ppm. RESULTS: There was a greater prevalence of wheezing (25%) among the bleachery workers with a history of gassings (from ozone, chlorine, or sulfur dioxide) than among those without gassings (18%) and among the referents (13%). Among the current smokers the fraction with a slightly increased bronchial responsiveness to methacholine was greater among the bleachery workers reporting gassings than among those that had not been gassed. For the period from 1992 to 1996, when the mills were using ozone, there was an increased incidence rate of wheezing among the workers in the bleachery (incidence rate ratio 2.3, 95% confidence interval 1.6-5.8). CONCLUSIONS: Repeated exposure to irritants increases the risk of asthma-like symptoms. This finding reinforces the view that repeated peak exposures to irritants must be prevented in pulp mills.
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