Carbon Monoxide Monitoring in Older Adults′ Homes in the West Midlands, United Kingdom

Carbon monoxide (CO) is an odourless, colourless gas that poses public health risk. A proportion of UK homes have low levels of CO that may pose risk to health, particularly in vulnerable groups such as older adults. The present study examined CO concentrations in older adults′ homes in Coventry, United Kingdom, with aims to understand exposure patterns and concentrations and associated sources. One hundred and five older adults (≥ 60 years) were recruited via liaison with West Midlands Fire Service during Safe and Well visits between October 2018 and June 2019. Fire officers installed CO data loggers and alarms and information on home appliances, alarms and smoking were collected. Continuous CO concentrations were monitored in 94 homes over 28 days. CO data were examined in relation to the World Health Organisation (WHO) air quality guidelines and associations between CO sources and presence of CO were explored. Of the 94 monitored homes, 53% had CO; 64% had CO concentrations ≥ 3.5 ppm, 24 % ≥ 8 ppm and 16 % ≥ 10 ppm at least once. Although low mean concentrations (0.15 ppm) were recorded, two homes exceeded WHO guideline limits of 8.7 ppm for ≥ 8 h, and one exceeded 3.5 ppm for ≥ 24 h. Exposure patterns varied, with prolonged low‐level concentrations and short‐lasting peaks up to 29 ppm. Homes monitored in the colder months and those with gas cookers had significantly higher odds of CO in the home, suggesting low‐level CO is associated with gas heating and cooking. Although CO concentrations were largely within current safety exposure limits, chronic low‐level exposures may go unnoticed without long‐term monitoring, potentially impacting health. This highlights the need for longer term monitoring combined with health assessment to build a more complete understanding of risk in domestic settings. Public health interventions are also needed to improve CO awareness.