Household characteristics associated with environmentally persistent free radicals in house dust in two Australian locations

Wen Ray Lee¹Prakash Dangal²Gaurav Langan¹Nina Lazarevic³Zhiwei Xu⁴Stephania Cormier⁵Slawo Lomnicki²Peter David Sly¹Dwan Vilcins^1*

• ¹Child Health Research Centre, Faculty of Medicine, The University of Queensland, Brisbane, Queensland, Australia
• ²Department of Environmental Sciences, College of the Coast & Environment, Louisiana State University, Baton Rouge, Louisiana, United States
• ³National Centre for Epidemiology and Population Health, College of Health and Medicine, Australian National University, Canberra, Australian Capital Territory, Australia
• ⁴School of Medicine and Dentistry, Griffith Health, Griffith University, Birtinya, Queensland, Australia
• ⁵Pennington Biomedical Research Center, Baton Rouge, Louisiana, United States

The association between air pollution and adverse health outcomes has been extensively studied, and while oxidative stress is likely to be involved, the underlying mechanism(s) remain unclear. Recent studies propose environmentally persistent free radicals (EPFRs) as the missing connection between air pollution and detrimental health impacts. However, the indoor environment is rarely considered in EPFR research. We measured EPFRs in household dust from two locations in Australia and investigated household characteristics associated with the presence of EPFRs. Lasso penalised regression models were used to identify important household characteristics.We used unpenalized linear regression and exact post-selection inference to obtain coefficient estimates of each identified household characteristic. We found that usage of extractor fan while cooking, traffic-related air pollution and ambient PM2.5, indoor combustion activities, season, housing structures, ventilation and cleaning habits were important household characteristics associated with EPFRs in Australian homes. Increased usage of extractor fan while cooking was consistently associated with lowered EPFR concentrations in household dust for both Australian locations.