Association between home insulation and hospital admission rates: retrospective cohort study using linked data from a national intervention programme
BMJ 2020; 371 doi: https://doi.org/10.1136/bmj.m4571 (Published 29 December 2020) Cite this as: BMJ 2020;371:m4571Linked Editorial
Housing as a public health investment
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Dear Editor,
Re: Association between home insulation and hospital admission rates: retrospective cohort study using linked data from a national intervention programme
This really interesting study found major health benefits of retrofitting insulation in New Zealand (NZ) homes.
Warmer, more comfortable homes (thanks to improved insulation) have other advantages. They save lives by reducing the need for wood heating. In NZ, 56% of all health costs of man-made air pollution were attributed to home wood heating – an estimated NZ$4,425 per wood heater per year.[1]
In 2005, NZ attempted to solve its pollution problem by introducing stricter wood stove standards than currently required anywhere else in the world. Sadly, the efforts failed. Average real-life emissions of new wood stoves were almost 8 times worse than lab test measurements, with virtually no relationship between real-life and lab test emissions.[2] The magnitude of NZ’s health problems was demonstrated by the ‘Growing up in NZ’ study, which reported a 7% increased risk of non-accidental hospital emergency presentations in children under 3 for every additional wood-heater per hectare.[3]
Similar health problems are now emerging in the UK. Dr Nick Hopkinson, medical director at the Asthma UK and British Lung Foundation highlighted the seriousness of the issue in Jan 2021, saying: 'To protect yourself and others, especially children who are particularly vulnerable as their lungs are smaller and still developing, avoid buying a wood-burning stove or using an open fire if you have another source of fuel to cook and heat your home with’. [4]
Experience in NZ implies that the current UK proposals for new stove standards and dry fuel are unlikely to make any real difference. The emissions limits for Eco-design stove (Table 2 of the Air Quality Expert Group’s Report[5]) are much higher than the 1.5 g/kg required since 2005 in all urban areas of NZ.
PM2.5 is the UK’s most health-hazardous air pollutant, associated with 32,900 premature deaths in 2018, five times worse than NO2 (6,000) and O3 (1,000).[6] Domestic wood combustion accounted for just 5.7% of the UK’s PM2.5 emissions in 1990, compared to 38% in 2018.[7]
Since 2014, UK PM2.5 emissions from all other sources fell by 5,746 tonnes (71.96 to 66.21 kt), but this was insufficient to offset the 6,492 tonne increase in wood stove emissions (34.18 to 40.68 kt), leading to 1,100 more PM2.5-related premature deaths in 2018 than 2016.[7] Yet only about 7.5% of UK households used wood heating in 2015 and only 2.5% used it as sole heating.[8]
Good choices depend on good advice. Sarah MacFadyen, head of policy at Asthma UK said: ‘We also need to see politicians doing more to raise awareness on the health dangers of wood and coal burning as part of a national health campaign on toxic air so people can make the best choices for their own health as well as the health of others around them’.[4]
Using a Defra-approved wood stove ‘nearly tripled harmful indoor pollution’.[9] The researchers recommended a health warning at the point of sale for new residential stoves to indicate the risks posed to users.[10]
Given the above, and that wood smoke contains the same and very similar toxic chemicals to cigarette smoke, health professionals should ideally reinforce Asthma UK’s message not to use wood stoves by supporting policies to: 1) not allow new stoves to be installed because of their really high health costs – thousands of pounds per stove per year and 2) provide subsidies to remove existing wood stoves.
We now know of the strong links between PM2.5 pollution and increased risk of Covid-19, that alternatives such as electric heat pumps help slow down global warming and provide cheaper heating for everyone who buys firewood. Consequently 1) and 2) above would be a win-win-win for the entire community!
Dr Dorothy L Robinson
Additional Information
1. Robinson, D.L. Accurate, Low Cost PM2.5 Measurements Demonstrate the Large Spatial Variation in Wood Smoke Pollution in Regional Australia and Improve Modeling and Estimates of Health Costs. Atmosphere 2020, 11, 856.
2. AAQG. Health Cost of Allowing New Wood Heaters – over $3,000 per heater per year; Australian Air Quality Group. Available at: http://woodsmoke.3sc.net/files/Health_Costs_Allowing_New_Wood_Heaters_Ap... 2020.
3. Lai, H.K.; Berry, S.D.; Verbiest, M.E.A.; Tricker, P.J.; Atatoa Carr, P.E.; Morton, S.M.B.; Grant, C.C. Emergency department visits of young children and long-term exposure to neighbourhood smoke from household heating – The Growing Up in New Zealand child cohort study. Environmental Pollution 2017, 231, 533-540, doi:https://doi.org/10.1016/j.envpol.2017.08.035.
4. Taylor, M. Avoid using wood burning stoves if possible, warn health experts. Guardian 1 Jan, 2021.
5. Air Quality Expert Group. The Potential Air Quality Impacts from Biomass Combustion. Available at: http://uk-air.defra.gov.uk/assets/documents/reports/cat11/1708081027_170... 2017.
6. EEA. European Environment Agency. Air quality in Europe — 2020 report. EEA Report No 09/2020. Available at: https://www.eea.europa.eu/publications/air-quality-in-europe-2020-report; 2020.
7. NAEI. UK emissions data selector. Available at http://naei.beis.gov.uk/data/data-selector?view=pms (select domestic combustion). Available online: (accessed on 1 August 2020).
8. UK DECC. Summary results of the domestic wood use survey. Department of Energy & Climate Change. Energy Trends: March 2016, special feature article. Available at: www.gov.uk/government/publications/energy-trends-march-2016-special-feat... 2016.
9. Carrington, D. Wood burners triple harmful indoor air pollution, study finds. 19 Dec. https://www.theguardian.com/environment/2020/dec/18/wood-burners-triple-...? 2020.
10. Chakraborty, R.; Heydon, J.; Mayfield, M.; Mihaylova, L. Indoor Air Pollution from Residential Stoves: Examining the Flooding of Particulate Matter into Homes during Real-World Use. Atmosphere 2020, 11, doi:10.3390/atmos11121326.
Competing interests: No competing interests
Dear Editor,
This well conducted and concluded study has implications for NZ and possibly for region(s) with similar climate and housing conditions. Other than respiratory infections, vascular response in terms of elevation of Blood Pressure is known and recognised. Interventional approach can be twofold -
a) assistance and provision for existing housing dwellings towards better protective insulation, which can be cumbersome.
b) Prospective legislative regulation that provides an inbuilt mechanism assuring optimal health protection. Assurance of protection from chronic environmental seasonal hazards is a part of SDGs.
Dr Murar E Yeolekar, Mumbai
Competing interests: No competing interests
Dear Editor
This study contributes to an existing body of knowledge on the adverse effects of poor housing on health, as the authors acknowledge. Unfortunately, as such, it is unlikely it will bring about a change, if that change has not already happened, based on what we already know.
The question at hand is why more has not been done to address the issue of poor housing (and everything that goes with deprivation)? To paraphrase an accepted phrase in sporting parlance, the obvious answer to all your questions is money.
When asked outright, most people would accept that there is a limited pot of money available for health care, if we accept that intervening in housing conditions is healthcare. What is not accepted is that the extent to which we must therefore choose wisely how this money is used (not to be confused with the "choosing wisely" programme), These choices will impinge on treatment availability, more so than many already accessing first world health treatments might like, doctors and patients alike. In the old days these types of limitations were called rationing or, its close cousin, stewardship.
To maintain the current investment patterns we enjoy, we rely on behaviours that appear to offer salvation from spiralling costs, such as the twin religions of leader-ism and more (and more) innovation. Largely these are things we sell each other as a panacea to the idea we should be doing something different, because more of the same will not do.
There is a third popular talking point, shifting our focus to illness prevention, but we have yet to deal with the idea that we cant have everything we have now in hospitals, and more, and more, and we can also find more money for investing in illness prevention.
Every year in the region I work in we admit up to a hundred children under the age of two years with preventable respiratory disease, and almost without exception we can map these children to areas of high deprivation. We know who they are and where they are.
Every year a relatively small group of people try valiantly to address this issue but without the kinds of funding and effort that continues to be poured into people at the end of their lives, at great cost. In comparison to the almost billion dollars it takes to operate hospital type services locally, the funding applied to improving basic living conditions is tiny. At least through health organisations.
It is easy to understand why it would be hugely unpopular politically to redirect funding from doing things of relatively low value for parts of the population that vote and are vociferous, and to put it into caring for people who would most benefit but are disenfranchised or simply too young to speak up for themselves. Easy to understand but not excusable.
The answer to all our problems cannot be more money. Courage will be required to spend the money where it does the most good. We know where and we know who.
Now we just need courage.
Competing interests: No competing interests
The Warmer the Healthier
Dear Editor
This research paper by Caroline Fyfe et al entitled “Association between home insulation and hospital admission rates: retrospective cohort study using linked data from a national intervention program,” was quite informative and crisp in showing how proper house insulation can reduce hospital admissions (relative rate ratio 0.89, 95% confidence interval 0.88 to 0.90) (Fyfe, 2020). Previous research by Philippa Howden-Chapman et al also concluded that hospital admissions especially among people with respiratory illnesses (asthma) (Howden-Chapman. P., 2007), benefited tremendously from house insulation. Vulnerable groups like children suffer most in colder climates since their body loses heat at a faster rate.
The Howden-Chapman et al study also found that parents who had home insulation reported a reduction in asthmatic symptoms, wheeze (adjusted odds ratio 0.51, 0.32 to 0.81) and dry cough (0.50, 0.31 to 0.82) (Howden-Chapman. P., 2007) in their children. In other vulnerable groups age ≥65yrs, Caroline Fyfe et al found that the most pronounced effect for ischemic heart disease related hospital admissions in those older than 65 years. Older people (≥65 years) have a greater vulnerability to cold housing because of comorbidities and more time spent in the home environment (Hamilton IG, 2017). This information from the study can be applied to other continents such as Europe and North America, where governments can put policies in place to create safer housing and safeguarding their vulnerable populations.
Bibliography
Fyfe, C. e. (2020). Association between home insulation and hospital admission. The BMJ, 371. doi:https://doi.org/10.1136/bmj.m4571
Hamilton IG, O. A. (2017). Old and cold? Findings on the determinants of indoor temperatures in English dwellings during cold conditions. Energy and Buildings, 142-57.
Howden-Chapman. P., e. a. (2007). Effect of insulating existing houses on health inequality:. The BMJ, 334. doi:doi:10.1136/bmj.39070.573032.80
Competing interests: No competing interests