Scientists discover link between dementia and open fires in the home

Scientists have found a link between cognitive decline in older people and coal and peat open fires in the home.

A study carried out by Lancaster University and The Irish Longitudinal Study on Ageing (TILDA) at Trinity College Dublin, revealed having open fires in the home negatively impacts cognitive health, with older women most affected as a consequence of that age group typically having spent more time at home.

The study was focused on Ireland where there are far greater numbers of open fire users than in other Western European countries. Nearly 7,000 people, aged 50 and over, took part in the study, and cognitive decline was analysed by widely-used cognitive tests including word recall and verbal fluency.

Dr Vincent O’Sullivan, joint lead researcher from Lancaster University Management School, said: “This collaborative study has found strong evidence of the health risks that open fire usage poses not just to older adults, but to people of all ages. We provide evidence that outlines the health risks open fires pose to cognitive function, and supports policies banning or restricting the use of open fires as a heat source, for example the UK government’s announcement earlier this year to phase out coal and wet wood use in 2021.

She points out that “traditionally, public health concerns about air pollution have been raised in relation to its negative effect on the heart and lungs” and adds: “Our research however demonstrates why cognitive function should be a key concern for policymakers to address, especially in Ireland, where open fire use is very common.”

Previous studies have shown air pollution is linked to harmful health conditions such as stroke, heart disease and lung cancer, as well as chronic and acute respiratory diseases like asthma.

Now, a growing body of scientific evidence has found links between air pollution and damage to neurodevelopment and cognitive function. Coal fires are one of the largest sources of fine particulate matter (PM2.5) with the smallest of these air pollution particles finding their way into the lungs and then the bloodstream.

Findings from the study of Irish people found peat-fuelled open fires emit higher particulate matter (PM) concentrations than coal and wood fires and magnetic content in particulate matter emitted from open fires is similar to that of roadside particulate matter.

As well as a link between open fire usage and cognition among older Irish people, scientists also found exposure to particulate matter from indoor open fire usage is similar to outdoor commuting exposure.

Professor Barbara Maher, joint lead researcher from Lancaster University, said: “Indoor air pollution forms when soot, particles and gases linger in the air inside a building, affecting the quality of the air inhaled into the lungs – the finest particles can even enter the brain directly through the olfactory nerves. We know that exposure to indoor air pollution affects both respiratory and cardiovascular health, but, before now, little was known about how it affects cognitive function in older adults.”

She added: “We discovered that the level of exposure to particulate matter from open fires is comparable to and may well exceed the levels people are exposed to from roadside sources. This is very concerning, not only for elderly people but especially for those who stay at home during the working day and use coal in their open fires.”

Government regulations implemented in Ireland earlier this year banned the use of smoky coal in all Irish towns with populations over 10,000 people. The regulations became law in July 2020, in an attempt to reduce air pollution in the country, promote public health and improve health outcomes.

To view the full paper published in the journal Environmental Research, ‘Indoor particulate air pollution from open fires and the cognitive function of older people’, visit: https://doi.org/10.1016/j.envres.2020.110298