West London Healthy Home and Environment Study (WellHome)

Children growing up in the UK today represent an 'indoor child generation', with most of their activities taking place within enclosed spaces, primarily homes and schools, with chemically diverse and often complex air quality environments. Despite its importance in human exposure terms, links between indoor air quality in its widest sense and public health is a under-researched area, particularly in the UK, with historically greater emphasis placed on outdoor air quality. Given the high incidence rates of childhood respiratory diseases in the UK we need a greater focus on eliminating the known triggers for the exacerbation of respiratory conditions such as asthma including the chemical and biological components of air pollution.

Furthermore, although epidemiological research has taught us a great deal about the health effects of air pollution, this has not been matched by toxicological research to define underlying mechanistic pathways. Given progress in both sciences is required to develop understanding of sources and risks we will develop enhanced toxicological approaches to lay the foundation for more effective policy development in years ahead. The ambition of this work is to go beyond a simple comparison of the toxicity of airborne particulate collected at different indoor environments, by integrating toxicological observations across microenvironments into an overall hazard to the individual, hence providing a tool to inform future policy.

Moving from the outdoor to indoor environment presents significant challenges to public health research, an ecological problem becomes a personal one; our homes are private spaces where we choose how to behave - smoking, cooking, heating, cleaning, ventilating - and policies encroaching upon that choice can be unpopular and/or inappropriate for specific subgroups. Furthermore, socio-economic circumstances can play a significant role in how much choice we have - housing quality, neighbourhood, insulation, home technology - leading to disparities in exposure as a function of socioeconomic status.

As such, the challenges that have faced the research community in addressing the most health relevant components of the outdoor aerosol are significantly magnified by adding a consideration of indoor air, where there are additional sources and unique chemical entities. Often, these additional sources are influenced or dictated by individual and household behaviours within the home. We will reduce the complexity of this challenge by focusing on established indoor and outdoor asthma triggers. Asthma affects one in five households in the UK and often these are children in deprived communities.

The programme of research in WellHome creates an innovative long-term research and information resource within an engaged urban community to advance knowledge and awareness of residential air quality, its health impacts and methods to ensure reduced exposure to harmful agents. This community research hub will be designed to directly address the challenges faced by urban communities, with a focus on households with sensitive inhabitants. The programme will be created with, and for, the urban population based in West London, a community with a relatively low socio-economic status and high ambient air pollution concentrations.

Through focusing on the indoor:outdoor continuum in a manageable number of homes with a vulnerable child, our intensive monitoring approach, toxicological assessments of chemical and biological PM with activity/time linked health data will provide a novel approach to the issue. Information gained from this community will be generalisable to other inner-city communities throughout England and the devolved administrations of the UK hence extending its usefulness beyond this project and leaving a valuable legacy.