Psychological and contextual drivers of indoor air quality behaviours in a deprived urban community: Evidence from participatory research

• Perceived severity, not vulnerability, predicts indoor air quality behaviours. • Mould and damp act as contextual cues for indoor air quality behaviours. • Participatory research can support behaviour change and boost self-efficacy. • Cooking and heating behaviours show increased probability of change over time. • Self-efficacy became a stronger predictor of behaviour over time. Indoor air pollution poses significant health risks, disproportionately affecting deprived communities that often face higher levels of exposure. This study, conducted as part of the WellHome project, employed a longitudinal design and a participatory research approach, directly involving 110 residents of a deprived urban area in West London in indoor air quality research. It tested an adapted Health Belief Model (HBM), tailored to indoor air quality behaviours, to examine how perceived vulnerability, perceived severity, self-efficacy, perceptions of indoor and outdoor air quality, and contextual cues to action relate to behavioural changes aimed at improving indoor air quality. It also assessed whether these factors predicted behaviour change over time, and explored patterns across various household behaviours, such as cooking, cleaning, heating, smoking, personal care, home fragrance use, window opening, and air purifier use. Results show that self-efficacy, perceived severity, perceptions of indoor and outdoor air quality, and cues to action were significantly associated with behaviour change, while perceived vulnerability was not. Notably, the influence of self-efficacy on behaviour increased over time, underscoring its role in sustaining long-term change. Visible cues, such as mould and damp, emerged as strong contextual triggers for action. Among the behaviours assessed, changes were most frequently reported in window opening, cooking, and cleaning, although a clear increase in change over time was only observed for cooking and heating. These findings suggest that a participatory approach can be effective in promoting healthier indoor environments in vulnerable communities.