Asthma symptoms and respiratory infections in Malaysian students-associations with ethnicity and chemical exposure at home and school

Dan Norbäck,Zailina Hashim,Faridah Ali,Jamal Hisham Hashim

doi:10.1016/j.envres.2021.111061

Abstract

Little is known on respiratory effects of indoor chemicals in the tropics. We investigated associations between asthma and respiratory infections in Malaysian students and chemical exposure at home and at school. Moreover, we investigated differences in home environment between the three main ethnic groups in Malaysia (Malay, Chinese, Indian). Totally, 462 students from 8 junior high schools in Johor Bahru participated (96% participation rate). The students answered a questionnaire on health and home environment. Climate, carbon dioxide (CO2), volatile organic compounds (VOC), formaldehyde and nitrogen dioxide (NO2) were measured inside and outside the schools. Multilevel logistic regression was applied to study associations between exposure and health. Totally 4.8% were smokers, 10.3% had wheeze, 9.3% current asthma, and had 18.8% any respiratory infection in the past 3 months. Malay students had more dampness or mould (p < 0.001), more environmental tobacco smoke (ETS) (p < 0.001) and more cats (p < 0.001) at home as compared to Chinese or Indian students. Wheeze was associated with ethnicity (p = 0.02; lower in Indian), atopy (p = 0.002), current smoking (p = 0.02) and recent indoor painting at home (p = 0.03). Current asthma was associated with ethnicity (p = 0.001; lower in Chinese) and para-dichlorobenzene in classroom air (p = 0.008). Respiratory infections were related to atopy (p = 0.002), ethylbenzene (p = 0.02) and para-dichlorobenzene (p = 0.01) in classroom air. Para-dichlorobenzene is used in Asia against insects. In conclusion, chemical emissions from recent indoor painting at home can increase the risk of wheeze. In schools, para-dichlorobenzene can increase the risk of current asthma and respiratory infections while ethylbenzene can increase the risk of respiratory infections.

Highlights

Childhood asthma has increased globally since the mid-20th century (Asher et al, 2006; Dietert and Zelikoff, 2008), especially in Asia (Pawankar et al, 2008)
Current asthma was related to ethnicity (p < 0.001) and was most common in Malay (15.5%) and least common in Chinese students (4.3%)
Wheeze, current asthma, and exposure to damp ness and mould, Environmental tobacco smoke (ETS) and furry pets at home differed between students from the three main different ethnic groups (Malay, Chinese, Indian) in Johor Bahru, Malaysia

Summary

Introduction

Childhood asthma has increased globally since the mid-20th century (Asher et al, 2006; Dietert and Zelikoff, 2008), especially in Asia (Pawankar et al, 2008). Environmental tobacco smoke (ETS) (Burke, 2012) and dampness and mould in the home (Quansah et al, 2012) can be risk factors for asthma. Furry pet allergens at home can influence allergic. Chemical emis sions from new materials used in renovations in homes can increase childhood allergic disease (Mendell, 2007). Three previous studies re ported that recent indoor painting, especially wood painting, can in crease the risk of asthma in adults (Wieslander et al, 1997; Wang et al, 2020) and school children (Fan et al, 2017)

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Results

Conclusion