Health Impact Evaluation

In this article we look into the public health impact of wood and solid fuel burning in London, as calculated by Ricardo Energy & Environment in the health impact evaluation commissioned as part of the London Wood Burning Project.

Air pollution is regarded as the largest environmental risk for health, and exposure to pollutants can affect us both at the point of exposure or over a prolonged period of time for long-term exposure.

We are all affected by air pollution but children, older people, and people with existing health conditions are more vulnerable[i]. Lower-income neighbourhoods and communities with a higher proportion of Black, Asian and minority ethnic residents are also statistically more likely to live in areas with worse air quality, so air pollution contributes to health inequalities[ii].

We know that wood and solid fuel burning is an important source of air pollution in London, amongst other sources such as road vehicles, gas heating and construction. We also know that air pollution causes many thousands of deaths and hospitalisations every year. However, it can be more challenging to apportion cumulative health outcomes  to the different sources of air pollution, and this can stand in the way of awareness campaigns and policy changes to clean up our air to protect everyone’s health.

One of the aims of the London Wood Burning Project is to raise public awareness about air pollution from home wood and solid fuel burning. To create an honest, accurate and meaningful campaign it was necessary to gain a better understanding of the specific public health burden associated with particulate matter (PM2.5) air pollution from domestic burning.

We commissioned Ricardo Energy & Environment to undertake a health impact evaluation to quantify this, including an estimation of the healthcare costs and economic impacts linked to the share of mortality and ill-health caused by wood and solid fuel burning in London.

The evaluation followed best practice methodology and used the most up-to-date set of air quality modelling data for London (the London Atmospheric Emissions Inventory or ‘LAEI’[iii]) as well as population statistics and guidance from the Committee on the Medical Effects of Air Pollutants (COMEAP) to investigate impacts across a range of health pathways with a robust and quantified relationship between pollution exposure and health effects.

This included asthma, lung cancer, stroke, coronary heart disease and diabetes, and the study was able to provide an estimate of the number of new cases and hospital admissions attributable to exposure to PM2.5 from wood burning as well as coal and oil burning (because emissions from coal and oil are combined in the LAEI dataset).

The annual health burden from domestic wood burning in London was found to include:

  • 284 deaths
  • 80 respiratory hospital admissions
  • 60 new cases of stroke
  • 50 new cases of coronary heart disease
  • 30 new cases of lung cancer
  • 90 new cases of asthma in children

Cumulatively this leads to the sobering statistic that wood burning causes more than 3,400 years of lost life each year, linked to a three-week reduction in life expectancy at birth for all persons in London. Years of life lost is a measure of premature mortality used to enumerate and compare the relative importance of different causes of premature death within a population.

Turning to financial implications, the quantification of healthcare costs found that wood burning imposes a £187 million burden on London every year, with a further £10 million in economic losses. This equates to a £24 cost per Londoner, every year.

The dispersed nature of particulate matter air pollution means that the health impacts from wood burning – and other pollution sources – are not constrained to the locality of emissions but are instead dispersed among the population. As a result, the health effects are borne across a wide area and can affect people regardless of whether or not they burn wood or other solid fuels at home themselves. In this way, wood burning contributes to the health inequality caused by air pollution in London.

It can be difficult to make sense of the health risks linked to air pollution, but it can be helpful to think of it in the same way that we think about the risks linked to other activities like smoking or driving. We know that smoking causes health damage, but it is not the case that every single smoker will die as a result of a health condition associated with tobacco or cigarettes. The expression of health impacts related to smoking is instead a reflection of the burden of illness and mortality as measured across a population.

We may often hear comparison of the risks of injury or death from driving compared to train travel or flying, and most people realise that our choosing to drive does not guarantee that we will experience a road accident, but it does increase the risk compared to us choosing not to drive or travelling by an alternative means.

We can think of wood burning in a similar way: if we are able to choose how to heat our home, our choice to avoid burning wood or solid fuels will help to reduce air pollution from heating and this will reduce the overall air pollution health risk that we experience. Our air is a shared resource, so our choice about heating also affects our neighbours and our community, and a choice to use gas or electric heating will be better for everyone’s health over the long term.

You can find out more by reading the full Health Impact Evaluation, or the Executive Summary for an overview of the methods and the findings.

[i] Office for Health Improvement & Disparities: Air pollution: applying All Our Health

[ii] Office for National Statistics: Does exposure to air pollution increase the risk of dying from the coronavirus (COVID-19)?

[iii] Greater London Authority: London Atmospheric Emissions Inventory (LAEI) 2019

Member London Boroughs