Traffic-related air pollution, oxidative stress genes, and asthma (ECHRS)

BACKGROUND: Traffic-related air pollution is related with asthma, and this association may be modified by genetic factors. OBJECTIVES: We investigated the role of genetic polymorphisms potentially modifying the association between home outdoor levels of modeled nitrogen dioxide and asthma. METHODS: Adults from 13 cities of the second European Community Respiratory Health Survey (ECRHS II) were included (n = 2,920), for whom both DNA and outdoor NO(2) estimates were available. Home addresses were geocoded and linked to modeled outdoor NO(2) estimates, as a marker of local traffic-related pollution. We examined asthma prevalence and evaluated polymorphisms in genes involved in oxidative stress pathways [gluthatione S-transferases M1 (GSTM1), T1 (GSTT1), and P1 (GSTP1) and NAD(P)H:quinine oxidoreductase (NQO1)], inflammatory response [tumor necrosis factor alpha (TNFA)], immunologic response [Toll-like receptor 4 (TLR4)], and airway reactivity [adrenergic receptor beta2 (ADRB2)]. RESULTS: The association between modeled NO(2) and asthma prevalence was significant for carriers of the most common genotypes of NQO1 rs2917666 [odds ratio (OR) = 1.54; 95% confidence interval (CI), 1.10-2.24], TNFA rs2844484 (OR = 2.02; 95% CI, 1.30-3.27). For new-onset asthma, the effect of NO(2) was significant for the most common genotype of NQO1 rs2917666 (OR = 1.52; 95% CI, 1.09-2.16). A significant interaction was found between NQO1 rs2917666 and NO(2) for asthma prevalence (p = 0.02) and new-onset asthma (p = 0.04). CONCLUSIONS: Genetic polymorphisms in the NQO1 gene are related to asthma susceptibility among persons exposed to local traffic-related air pollution. This points to the importance of antioxidant pathways in the protection against the effects of air pollution on asthm

Volatile organic compounds (VOC), formaldehyde and nitrogen dioxide (NO2) in schools in Johor Bahru, Malaysia: associations with rhinitis, ocular, throat and dermal symptoms, headache and fatigue

This paper studied associations between volatile organic compounds (VOC), formaldehyde, nitrogen dioxide (NO2) and carbon dioxide (CO2) in schools in Malaysia and rhinitis, ocular, nasal and dermal symptoms, headache and fatigue among students. Pupils from eight randomly selected junior high schools in Johor Bahru, Malaysia (N = 462), participated (96%). VOC, formaldehyde and NO2 were measured by diffusion sampling (one week) and VOC also by pumped air sampling during class. Associations were calculated by multi-level logistic regression adjusting for personal factors, the home environment and microbial compounds in the school dust. The prevalence of weekly rhinitis, ocular, throat and dermal symptoms were 18.8%, 11.6%, 15.6%, and 11.1%, respectively. Totally 20.6% had weekly headache and 22.1% fatigue. Indoor CO2 were low (range 380–690 ppm). Indoor median NO2 and formaldehyde concentrations over one week were 23 μg/m3 and 2.0 μg/m3, respectively. Median indoor concentration of toluene, ethylbenzene, xylene, and limonene over one week were 12.3, 1.6, 78.4 and 3.4 μg/m3, respectively. For benzaldehyde, the mean indoor concentration was 2.0 μg/m3 (median < 1 μg/m3). Median indoor levels during class of benzene and cyclohexane were 4.6 and 3.7 μg/m3, respectively. NO2 was associated with ocular symptoms (p < 0.001) and fatigue (p = 0.01). Formaldehyde was associated with ocular (p = 0.004), throat symptoms (p = 0.006) and fatigue (p = 0.001). Xylene was associated with fatigue (p < 0.001) and benzaldehyde was associated with headache (p = 0.03). In conclusion, xylene, benzaldehyde, formaldehyde and NO2 in schools can be risk factors for ocular and throat symptoms and fatigue among students in Malaysia. The indoor and outdoor levels of benzene were often higher than the EU standard of 5 μg/m3

Endotoxin, ergosterol, muramic acid and fungal DNA in dust from schools in Johor Bahru, Malaysia — associations with rhinitis and sick building syndrome (SBS) in junior high school students

This paper studied associations between ocular symptoms, rhinitis, throat and dermal symptoms, headache and fatigue in students by ethnicity and in relation to exposure to chemical microbial markers and fungal DNA in vacuumed dust in schools in Malaysia. A total of 462 students from 8 randomly selected secondary schools in Johor Bahru, Malaysia, participated (96% response rate). Dust was vacuumed from 32 classrooms and analysed for levels of five types of endotoxin as 3-hydroxy fatty acids (C10, C12, C14, C16 and C18 3-OH), muramic acid, ergosterol and five sequences of fungal DNA. Multiple logistic regression was applied. Totally 11.9% reported weekly ocular symptoms, 18.8% rhinitis, 15.6% throat and 11.1% dermal symptoms, 20.6% headache and 22.1% tiredness. Totally 21.1% reported pollen or furry pet allergy (atopy) and 22.0% parental asthma or allergy. Chinese students had less headache than Malay and Indian had less rhinitis and less tiredness than Malay. Parental asthma/allergy was a risk factor for ocular (odds ratio = 3.79) and rhinitis symptoms (OR = 3.48). Atopy was a risk factor for throat symptoms (OR = 2.66), headache (OR = 2.13) and tiredness (OR = 2.02). There were positive associations between amount of fine dust in the dust samples and ocular symptoms (p < 0.001) and rhinitis (p = 0.006). There were positive associations between C14 3-OH and rhinitis (p < 0.001) and between C18 3-OH and dermal symptoms (p = 0.007). There were negative (protective) associations between levels of total endotoxin (LPS) (p = 0.004) and levels of ergosterol (p = 0.03) and rhinitis and between C12 3-OH and throat symptoms (p = 0.004). In conclusion, the amount of fine dust in the classroom was associated with rhinitis and other SBS symptoms and improved cleaning of the schools is important. Endotoxin in the school dust seems to be mainly protective for rhinitis and throat symptoms but different types of endotoxin could have different effects. The ethnic differences in symptoms among the students deserve further attention

Fractional exhaled nitric oxide (FeNO) among office workers in an academic institution, Malaysia – associations with asthma, allergies and office environment

Objective: There are few studies on fractional exhaled nitric oxide (FeNO) and respiratory symptoms among adults in tropical areas. The aim was to study associations between FeNO and selected personal factors, respiratory symptoms, allergies, office characteristics and indoor office exposures among office workers (n = 460) from a university in Malaysia. Methods: Information on health was collected by a questionnaire, skin prick test and FeNO measurement. Temperature, relative air humidity, carbon monoxide and carbon dioxide were measured in the offices. Settled dust was vacuumed in the offices and analyzed for endotoxin, (1,3)-β-glucan and house dust mites allergens, namely Dermatophagoides pteronyssinus (Der p 1) and Dermatophagoides farinae (Der f 1). Two-level linear mixed models and multiple logistic regression were used to analyze the associations. Results: One-fourth (25.9%) of the office workers had elevated FeNO level (≥25 ppb) and 61.5% had HDM, cat, seafood or pollen allergy. Male gender (p < 0.001), current smoking (p = 0.037), height (p < 0.001) and atopy (p < 0.001) were associated with FeNO. The amount of vacuumed dust was associated with FeNO among atopic subjects (p = 0.009). Asthma and rhinitis symptoms were associated with FeNO (p < 0.05), especially among atopic subjects. In particular, a combination of atopy and elevated FeNO were associated with doctor-diagnosed asthma (p < 0.001), rhinitis (p < 0.001) and airway symptoms last 12 months (p < 0.001). Conclusion: Gender, smoking, height and atopy are important risk factors for elevated FeNO levels. A combination of allergy testing and FeNO measurement could be useful in respiratory illness epidemiology studies and patient investigations in tropical areas

Latitude, Birth Date, and Allergy

BACKGROUND: The space and time distribution of risk factors for allergic diseases may provide insights into disease mechanisms. Allergy is believed to vary by month of birth, but multinational studies taking into account latitude have not been conducted. METHODS AND FINDINGS: A questionnaire was distributed in 54 centres to a representative sample of 20- to 44-y-old men and women mainly in Europe but also including regions in North Africa, India, North America, Australia, and New Zealand. Data from 200,682 participants were analyzed. The median prevalence of allergic rhinitis was 22%, with a substantial variation across centres. Overall, allergic rhinitis decreased with geographical latitude, but there were many exceptions. No increase in prevalence during certain winters could be observed. Also, no altered risk by birth month was found, except borderline reduced risks in September and October. Effect estimates obtained by a multivariate analysis of total and specific IgE values in 18,085 individuals also excluded major birth month effects and confirmed the independent effect of language grouping. CONCLUSION: Neither time point of first exposure to certain allergens nor early infections during winter months seems to be a major factor for adult allergy. Although there might be effects of climate or environmental UV exposure by latitude, influences within language groups seem to be more important, reflecting so far unknown genetic or cultural risk factors