Air pollution and respiratory health in patients with COPD

I've just added a new resource to the network, and wanted to bring it to everyone's attention (I know my notifications only tell me about topics rather than new resources, but apologies if you end up seeing this twice!). 

The study, titled "Air pollution and respiratory health in patients with COPD: should we focus on indoor or outdoor sources?", by Evangelopoulos et al, was published on-line in Thorax on 7/10/24. In this study, the researchers continuously measured individual exposure to indoor and outdoor-generated air pollution, in 76 patients with COPD, for an average of 134 days. They compared this with information collected daily about patient's symptoms and peak flow readings. The study found that exposure to both indoor and outdoor sources was associated with increased exacerbations and respiratory symptoms. For example, an increase by the IQR in exposure to NO2 was associated with a 33% increase in the odds of an exacerbation. The association was stronger for indoor (odds ratio 1.19) compared to outdoor (odds ratio 1.12) air pollution. Higher NO2 and carbon monoxide exposure were both associated with more reported respiratory symptoms. The most common source of NO2 indoors is from gas cookers (and to a lesser extent, heating), whilst outdoors it is road transport.

The authors conclude "Regulating day-to-day exposure to both indoor and outdoor sources of gaseous pollution is important to the respiratory health of patients with COPD in London. There are actions that patients can take to reduce these exposures as well as legislative interventions. Those caring for patients with COPD should be aware of these actions and provide appropriate advice. Those with respiratory conditions should avoid the use of gas cookers where possible."

I found this a really eye-opening study. As well as reminding me of the importance of outdoor air pollution, it made me re-consider the potential risks of things that many of us take for granted, like using a gas-cooker (which I did until a few years ago), and having gas central heating (which I still do). I had never thought to explore the cooking or heating sources that patients with COPD use (unless considering home oxygen of course!). But this paper has made me realise that these factors, along with outdoor air pollution, could be contributing to patient's symptoms and exacerbations. I am now wondering if I should start asking patients about their cooking and heating sources, along with their exposure to outdoor air pollution, especially if they are frequently exacerbating. It might not be possible for patients to change these, but making them aware of the potential risk from them is the first step. This will allow them to consider whether they want to reduce their exposure and think about how they could do this (for example avoiding being in the kitchen when the gas cooker is being used, improved ventilation, ensuring the gas boiler is regularly serviced, and considering using quieter travel routes). I would be really interested to hear from anyone who does already discuss these factors with these patients, or offers any advice to patients about how to reduce their exposure to indoor air pollution.