Differential exposures to housing risk factors are frequently inversely associated with social position. In England, 35% of people in the lowest income quintile live in ‘non-decent’ housing, compared to 24% in the highest income quintile. ‘Non-decent’ describes housing that is not warm enough, in a state of disrepair or does not have modern facilities.[i] In Cambodia, toilet facilities are available to 29% of households in the lowest income quintile, compared to 79% of the households in the highest income quintile.[ii] In Africa, 90% of the households in the lowest income quintile use solid fuels for cooking, while about half of households in the highest income quintile use solid fuels for cooking.[iii]
Differential health outcomes. There are major inequalities in health outcome for illnesses related to housing. In New Zealand those living in the most deprived neighbourhoods have almost three times the risk of being hospitalised with a serious infectious disease compared with those living in the most affluent areas.[iv] In the United States, repeated hospitalizations for childhood asthma are correlated with children residing in the census tracts with the highest proportion of crowded housing conditions, largest number of racial minorities, and highest neighborhood-level poverty.[v] Exposure to household air pollution, which, as noted, is higher in low-income countries and households, almost doubles the risk for childhood pneumonia. Over half of deaths among children less than 5 years old from acute lower respiratory infections (ALRI) are due to particulate matter inhaled from indoor air pollution from household solid fuel.[vi]
Differential consequences: Through a number of pathways, inadequate housing affects other social outcomes. Reducing crowding has been linked to improved educational outcomes, as children are able to study more effectively when there is more space in their home.[vii][viii] Improving thermal comfort through installing insulation and heating has been shown to reduce days off school and work. This indicates that people miss out on education and employment opportunities partly due to illnesses caused by cold housing.[ix] Socio-economic circumstances affect the extent to which people can access adequate housing, and inadequate housing can exacerbate economic inequalities by harming education and employment opportunities.
Differential vulnerabilities. Children, the elderly, and those with a disability or chronic illness are more likely than other people to spend much of their time at home, and are therefore most exposed to health risks associated with housing.[x] In settings where solid fuels are used for cooking and heating, women and children are particularly exposed to risks associated with injury and poor air quality, because they spend more time near the domestic hearth.[xi] Children are more vulnerable to indoor exposures to dangerous substances such as lead, due to their behaviour, the low level of immune system capacity, and the fact that they have – relative to body weight – a much higher intake of pollutants than adults.[xii]
Analysis of exposure over the life-course to advantage and disadvantage shows that these negative and positive factors and processes accumulate over time, influencing epigenetical, psychosocial, physiological, and behavioural attributes among individuals as well as social conditions in families, communities, and social groups including gen- der. This accumulation of advantage and disadvantage leads to social and economic inequities and consequently to inequitable mental and physical health outcomes. These processes are dynamic, in the sense that the accumulation of positive and negative influences takes place throughout life.
[i] Department for Communities and Local Government. 2015. English Housing Survey 2013/2014. London: Department for Communities and Local Government.
[iii] Global health observatory, urban health [website]. Geneva: World Health Organization; 2015 (http://www.who.int/gho/urban_health/en/, accessed 5 December 2015). http://www.who.int/kobe_centre/measuring/urban-global-report/ugr_full_report.pdf?ua=1
[v] Liu SY, Pearlman DN. Hospital readmissions for childhood asthma: the role of individual and neighborhood factors. Public Health Rep. 2009;124(1):65---78. 25.
[vi] WHO 2014
[vii] Braconi 2001
[ix] Howden Chapman 2007 and 2008 BMJ
[x] Baker, M, M Keall, E. L. Au, and P Howden-Chapman. 2007. “Home Is Where the Heart Is - Most of the Time.” New Zealand Medical Journal 120 (1264): 67–69.
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Leech JA, Nelson WC, Burnett RT, et al. It's about time: a comparison of Canadian and American timeactivity patterns. J Expo Anal Environ Epidemiol. 2002;12:42732.
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Briggs DJ, Denman AR, Gulliver J, et al. Time activity modelling of domestic exposures to radon. J Environ Manage. 2003;67:10720
[xii] Bearer CF Environmental health hazards: how children are different from adults. Future Child. 1995 Summer-Fall;5(2):11-26.