Gui-Hong Cai

Total viable molds and fungal DNA in classrooms and association with respiratory health and pulmonary function of European schoolchildren.

To cite this article: Simoni M, Cai G‐H, Norback D, Annesi‐Maesano I, Lavaud F, Sigsgaard T, Wieslander G, Nystad W, Canciani M, Viegi G, Sestini P. Total viable molds and fungal DNA in classrooms and association with respiratory health and pulmonary function of European schoolchildren. Pediatr Allergy Immunol 2011: 22: 843–852.

Indoor air quality, ventilation and respiratory health in elderly residents living in nursing homes in Europe

Few data exist on respiratory effects of indoor air quality and comfort parameters in the elderly. In the context of the GERIE study, we investigated for the first time the relationships of these factors to respiratory morbidity among elderly people permanently living in nursing homes in seven European countries. 600 elderly people from 50 nursing homes underwent a medical examination and completed a standardised questionnaire. Air quality and comfort parameters were objectively assessed in situ in the nursing home. Mean concentrations of air pollutants did not exceed the existing standards. Forced expiratory volume in 1 s/forced vital capacity ratio was highly significantly related to elevated levels of particles with a 50% cut-off aerodynamic diameter of <0.1 µm (PM0.1) (adjusted OR 8.16, 95% CI 2.24–29.3) and nitrogen dioxide (aOR 3.74, 95% CI 1.06–13.1). Excess risks for usual breathlessness and cough were found with elevated PM10 (aOR 1.53 (95% CI 1.15–2.07) and aOR 1.73 (95% CI 1.17–10.3), respectively) and nitrogen dioxide (aOR 1.58 (95% CI 1.15–2.20) and aOR 1.56 (95% CI 1.03–2.41), respectively). Excess risks for wheeze in the past year were found with PM0.1 (aOR 2.82, 95% CI 1.15–7.02) and for chronic obstructive pulmonary disease and exhaled carbon monoxide with formaldehyde (aOR 3.49 (95% CI 1.17–10.3) and aOR 1.25 (95% CI 1.02–1.55), respectively). Breathlessness and cough were associated with higher carbon dioxide. Relative humidity was inversely related to wheeze in the past year and usual cough. Elderly subjects aged ≥80 years were at higher risk. Pollutant effects were more pronounced in the case of poor ventilation. Even at low levels, indoor air quality affected respiratory health in elderly people permanently living in nursing homes, with frailty increasing with age. The effects were modulated by ventilation. Poor air quality in European nursing homes impairs respiratory health in the elderly permanently living in them http://ow.ly/Es8VQ

Fungal DNA and pet allergen levels in Swedish day care centers and associations with building characteristics.

Pet allergens and mold growth related to damp are common phenomena in day care centers in Sweden but exposure measurements of these factors are lacking. The aim of this study was to investigate the relationship between building construction and indoor environment quality in Swedish day care centers and the potential for exposure to fungi (analyzed by quantitative PCR) and animal allergens (analyzed by ELISA). Measurements were performed in 21 day care centers (103 rooms) from one municipality in Sweden, which were identified as constructions at risk of dampness (85% of the buildings) and with visible damage and mold growth (54% of the buildings). Dust samples were collected using cotton swab and Petri dishes. Total fungal DNA was detected in 99% and 100%, Aspergillus/Penicillium DNA in 54% and 68%, and Stachybotrys chartarum DNA in 4% and 9% of the investigated rooms in cotton swab and Petri dish samples, respectively. The total fungal DNA levels (Geometric Mean, GM) were 4.2 × 10(6) cell equivalents per m(2) and 2.9 × 10(5) cell equivalents per m(2) per day in the swab and Petri dish samples, respectively. The concentrations (GM) of cat (Fel d1), dog (Can f1), and horse (Equ cx) allergens were 9.4, 7.2 ng m(-2) day(-1), and 5.0 unit per m(2) per day, respectively. Total fungal DNA levels were higher in risk construction buildings (p = 0.01), in rooms with linoleum flooring material (p = 0.003), and in buildings with rotating heat exchangers (p = 0.02). There were associations between total fungal DNA levels and cat (p = 0.02), dog (p < 0.001), and horse (p = 0.001) allergens. In conclusion, risk constructions, damp constructions, mould growth, fungal DNA, and animal allergens were common exposure factors in Swedish day care centers. Building constructions that represent a high risk for internal dampness should be avoided in the future, and measures to reduce allergen levels should be considered to protect pet-allergic children from asthmatic problems.

Fungal DNA in hotel rooms in Europe and Asia--associations with latitude, precipitation, building data, room characteristics and hotel ranking.

There is little information on the indoor environment in hotels. Analysis of fungal DNA by quantitative PCR (qPCR) is a new method which can detect general and specific sequences. Dust was collected through swab sampling of door frames in 69 hotel rooms in 20 countries in Europe and Asia (2007-2009). Five sequences were detected by qPCR: total fungal DNA, Aspergillus and Penicillium DNA (Asp/Pen DNA), Aspergillus versicolor (A. versicolor DNA), Stachybotrys chartarum (S. chartarum DNA) and Streptomyces spp. (Streptomyces DNA). Associations were analysed by multiple linear regression. Total fungal DNA (GM = 1.08 × 10(8) cell equivalents m(-2); GSD = 6.36) and Asp/Pen DNA (GM = 1.79 × 10(7) cell equivalents m(-2); GSD = 10.12) were detected in all rooms. A. versicolor DNA, S. chartarum DNA and Streptomyces DNA were detected in 84%, 28% and 47% of the samples. In total, 20% of the rooms had observed dampness/mould, and 30% had odour. Low latitude (range 1.5-64.2 degrees) was a predictor of Asp/Pen DNA. Seaside location, lack of mechanical ventilation, and dampness or mould were other predictors of total fungal DNA and Asp/Pen DNA. Hotel ranking (Trip Advisor) or self-rated quality of the interior of the hotel room was a predictor of total fungal DNA, A. versicolor DNA and Streptomyces DNA. Odour was a predictor of S. chartarum DNA. In conclusion, fungal DNA in swab samples from hotel rooms was related to latitude, seaside location, ventilation, visible dampness and indoor mould growth. Hotels in tropical areas may have 10-100 times higher levels of common moulds such as Aspergillus and Penicillium species, as compared to a temperate climate zone.

Furry pet allergens, fungal DNA and microbial volatile organic compounds (MVOCs) in the commercial aircraft cabin environment

There has been concern about the cabin environment in commercial aircraft. We measured cat, dog and horse allergens and fungal DNA in cabin dust and microbial volatile organic compounds (MVOCs) in cabin air. Samples were collected from two European airline companies, one with cabins having textile seats (TSC) and the other with cabins having leather seats (LSC), 9 airplanes from each company. Dust was vacuumed from seats and floors in the flight deck and different parts of the cabin. Cat (Fel d1), dog (Can f1) and horse allergens (Equ cx) were analyzed by ELISA. Five sequences of fungal DNA were analyzed by quantitative PCR. MVOCs were sampled on charcoal tubes in 42 TSC flights, and 17 compounds were analyzed by gas chromatography mass spectrometry (GC-MS) with selective ion monitoring (SIM). MVOC levels were compared with levels in homes from Nordic countries. The weight of dust was 1.8 times larger in TSC cabins as compared to LSC cabins (p < 0.001). In cabins with textile seats, the geometric mean (GM) concentrations of Fel d1, Can f1 and Equ cx were 5359 ng g(-1), 6067 ng g(-1), and 13 703 ng g(-1) (GM) respectively. Levels of Fel d1, Can f1 and Equ cx were 50 times, 27 times and 75 times higher respectively, in TSC cabins as compared to LSC cabins (p < 0.001). GM levels of Aspergillus/Penicillium DNA, Aspergillus versicolor DNA, Stachybotrys chartarum DNA and Streptomyces DNA were all higher in TSC as compared to LSC (p < 0.05). The sum of MVOCs in cabin air (excluding butanols) was 3192 ng m(-3) (GM), 3.7 times higher than in homes (p < 0.001) and 2-methyl-1-butanol and 3-methyl-1-butanol concentrations were 15-17 times higher as compared to homes (p < 0.001). Concentrations of isobutanol, 1-butanol, dimethyldisulfide, 2-hexanone, 2-heptanone, 3-octanone, isobutyl acetate and ethyl-2-methylbutyrate were lower in cabin air as compared to homes (p < 0.05). In conclusion, textile seats are much more contaminated by pet allergens and fungal DNA than leather seats. The use of seats with smooth surfaces should be encouraged. The MVOC levels differed between cabin air and homes.

Dampness, indoor mould, fungal DNA and respiratory health – molecular methods in indoor epidemiology

Dampness, indoor mould, fungal DNA and respiratory health - molecular methods in indoor epidemiology

Respiratory symptoms and fractional exhaled nitric oxide (FeNO) among students in Penang, Malaysia in relation to signs of dampness at school and fungal DNA in school dust.

Few health studies exist on dampness and mould in schools in the tropics. We studied associations between fraction of exhaled nitric oxide (FeNO), respiratory symptoms and airway infections among students and dampness and fungal DNA in schools in Malaysia. A total of 368 randomly selected students from 32 classrooms in 8 secondary schools in Penang, Malaysia, participated (58% participation rate). Information on current respiratory symptoms and the home environment was collected by a standardised questionnaire. FeNO was measured by NIOX MINO (50ml/min). The classrooms were inspected and dust was collected by vacuuming on special filters and was analysed for five fungal DNA sequences by quantitative PCR. Linear mixed models and 3-level multiple logistic regression (school, classroom, student) were applied adjusting for demographic data and the home environment. Totally 10.3% reported doctors diagnosed asthma, 15.1% current wheeze, 12.4% current asthma, 37.3% daytime breathlessness, 10.2% nocturnal breathlessness, 38.9% airway infections and 15.5% had pollen or furry pet allergy. The geometric mean of FeNO was 19.9ppb and 45% had elevated FeNO (>20ppb). Boys had higher levels of FeNO. Chinese had less daytime breathlessness than Malay (OR=0.30: p<0.001). Indoor carbon dioxide levels were low (380-720ppm). Dampness was observed in 18% of the classrooms and was associated with respiratory infections (OR=3.70; 95% CI 1.14-12.1) and FeNO (p=0.04). Aspergillus versicolor DNA was detected in 67% of the classrooms. Higher numbers of Aspergillus versicolor DNA in classroom dust were associated with wheeze (p=0.006), current asthma (p=0.002), respiratory infections (p=0.005) and elevated FeNO levels (p=0.02). In conclusion, respiratory symptoms were common among the students and the high FeNO levels indicate ongoing airway inflammation. Building dampness and the mould Aspergillus versicolor in schools in Malaysia can be risk factors for impaired respiratory health among the students.

Cat, Dog and Horse Allergens in Swedish Day Care Centres-Associations with Fractional Exhaled Nitric Oxide (FeNO) among Day Care Centre Staff

PURPOSE To study associations between cat, dog and horse allergens in day care centres and fractional exhaled nitric oxide (FeNO), eosinophilic cationic protein (ECP) in serum, lung function (FEV1) and dyspnoea in day care centre staff. Totally 62 subjects, all females, from five Swedish day care centres participated (participation rate 90%). METHODS Dust was collected by vacuum cleaning and Petri dish sampling and analysed for cat (Fel d 1), dog (Can f 1) and horse (Ecu cx) allergens by ELISA. Dyspnoea was measured on an analogue rating scale. FeNO, serum ECP and symptom ratings were log-transformed. Associations were analysed by linear mixed models, adjusting for personal and home environment factors. RESULTS Geometric mean (GM) value for allergens in vacuumed dust were 1199 ng/g for Fel d 1, 666 ng/g for Can f 1 and 478 U/g for Equ cx, respectively. GM value for allergens in Petri dish samples (ng/m2 per day) was 29.8 for Fel d 1 and 9.1 for Can f 1, respectively. Cat allergen (Fel d 1) were positively associated with FeNO both in vacuumed dust (p=0.03) and in Petri dish samples (p=0.03). Dog allergen (Can f 1) in Petri dish samples was negatively associated with FeNO (p=0.02). Horse allergen (Equ cx) in vacuumed dust was negatively associated with FeNO (P=0.03). CONCLUSION Cat, dog and horse allergens were commonly found and cat allergen in day care centres can be a risk factor for lower airway inflammation, measured as FeNO, while dog and horse allergens were associated with lower FeNO.