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

Abstract

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.

Ocular symptoms and tear film break up time (BUT) among junior high school students in Penang, Malaysia – Associations with fungal DNA in school dust

“…The prevalence of weekly eye symptoms was 17.4%, higher than the 11.6% prevalence found in our previous school environment study in Johor Bahru, Malaysia (Norbäck et al, 2016a) and higher than the 6.5% prevalence of dry eye syndrome among adults in Singapore (Tong et al, 2009). In our study, the medians of SBUT and NIBUT were 14.8 and 12.2 s, respectively.…”

“…We have previously demonstrated that there is an association between latitude and the level of indoor fungal DNA and the highest levels of moulds can be found in countries near the equator . In a previous school environment study from Johor Bahru, Malaysia, we found associations between total fungal DNA levels in schools and eye symptoms among the students, especially for the mould Aspergillus versicolor (Norbäck et al, 2016a). Moreover there was an association between the amount of fine dust in the classrooms and eye symptoms (Norbäck et al, 2016b).…”

“…The filter is made of cellulose acetate, and according to the manufacturer it retains 74% of particles 0.3-0.5 m, 81% of particles 0.5-1.0 m, 95% of particles 1-10 m and about 100% of larger particles (>10 m). Vacuuming was performed for 4 min per sample, 2 min on the floor and 2 min on other surfaces (desks, chairs) as in previous school studies (Zhao et al, 2008;Zhang et al, 2011;Norbäck et al, 2016a). Each classroom was divided into two parts, one near the corridor and the one near the windows.…”

Targeted Inspection of Environmental Mycological Load for Mitigation of Indoor Mold toward Improved Public Health

“…These can include EI and long-term sampling, e.g. of settled dust or pumped air, and use of total fungal analyses, such as for ergosterol, beta 1-3 glucan or total molds by the CAMERANEA method [21][22][23] or fungal DNA analysis via quantitative or qualitative polymerase chain reaction (PCR) [21][22][23][24].…”

“…Environmental inspections (EIs) of mycological load have been suggested using a range of fungal-detection techniques, e.g. open Petri dish (OPD) versus active air sampling [19,20] and qualitative identification and quantitative monitoring of diverse fungal species and their mycotoxins [21][22][23][24].…”