Prolonged exposure to low-level carbon monoxide increasingly impairs cognitive ability in older adults, a new study has found.
A three-year project, led by Beth Cheshire as part of her PhD at Lancaster University, investigated the effects of CO on older people and found that the negative effect of ageing on cognition was worsened by greater overall exposure.
Beth says: “The results provide preliminary evidence of the neuropsychological effects of chronic low-level CO exposure in older adults.”
Older adults are more vulnerable to CO exposure because of a combination of factors, from increased susceptibility to pre-existing disease, and they’re also likely to spend more time at home, further increasing the risk.
Working with West Midlands Fire Service, the study collected CO levels over one month in 106 older adult homes in Coventry (all below levels that would trigger a CO alarm: 50 parts per million for 60 to 90 minutes). Follow-up CO monitoring and assessments were carried out at seven months to examine any longer-term impacts of exposure.
Seventy of these homes (66 per cent) had some CO present over the initial one-month monitoring period. Of these, 78 participants completed the follow-up at seven months, of which 47 (60 per cent) had some CO present. These results indicate a high prevalence of low-level CO within older adult homes in Coventry. However, the CO levels did not exceed those currently recommended to be safe by the WHO in any home.
Adrian McConnell, head of Charitable Operations at the CO Research Trust, which funded the project, says: “Determining the levels at which low-level chronic exposures become harmful would be invaluable in informing policy, guidelines and safety technology in order to keep those most vulnerable safe. There is a significant knowledge gap in this area, which is why we were keen to fund this project. However, it is clear that there is more work to be done.”
Identifying specific cognitive areas that are affected by chronic low-level CO exposure would also provide information on possible patterns of impairment that would help clinicians to diagnose low-level CO exposure, says the Trust.