Carbon monoxide (CO) is a colourless and odourless poisonous gas formed from the incomplete combustion of substances containing carbon. In the United Kingdom, over 22 million homes have mains or liquefied petroleum gas and consequently there is particular concern regarding potential CO poisoning resulting from malfunctioning domestic gas appliances. Although the number of reported cases of CO poisoning in the United Kingdom is relatively small, there is a high probability of misdiagnosis of the condition due to the ambiguous clinical symptoms of CO poisoning; incidence may therefore be much higher than currently reported. This review discusses the current knowledge on human health and toxicological effects following exposure to CO, focusing particularly on the public health impacts associated with gas appliances in UK homes. In determining the possibility of an underlying threat, the biological plausibility of misdiagnosis, in combination with reported cases, is discussed. The implication of misdiagnosis for public health treatment is also briefly summarised.
UK Department of Health: Letters from the Interim Chief Medical Officer and the Chief Nursing officer: Carbon monoxide poisoning: Needless deaths, unnecessary injury. PL/CMO/2010/02, UK, 2010.
2.
European Commission: The INDEX project: Critical Appraisal of the Setting and Implementation of Indoor Exposure Limits in the EU. Final Report, European Commission, Joint Research Centre, Institute for Health and Consumer Protection, Physical and Chemical Exposure unit, I-21020 Ispra (VA), Italy, 2005.
3.
UK Department of Health: Guidance on the effects on health of indoor air pollutants, Committee on the Medical Effects of Air Pollutants, 2004.
WHO: Carbon monoxide. Environmental Health Criteria EHC 213, World Health Organisation, Geneva, 1999.
6.
GreenEShortSShukerLKHarrisonPTC: Carbon monoxide exposure in the home environment and the evaluation of risks to health: Indoor Built Environ1999;8:168–175.
7.
CroxfordBHutchinsonELeonardiGSMcKennaLNicholsonLVolansGWilkinsonP: Real time carbon monoxide measurements from 270 UK homes; in RaleighJJ (eds): Proceedings of Indoor Environmental Quality (IEQ) – Problems, Research, and Solutions, Air and Waste Management Association (A&WMA) and US EPA's Office of Research and Development, North Carolina, USA, 2005.
8.
RawGCowardSBrownVCrumpD: Exposure to air pollutants in English homes: J Exposure Anal Environ Epidemiol2004;14:S85–S94.
9.
YuCWFKimJT: Building environmental Assessment Schemes for Rating of IAQ in sustainable Buildings: Indoor Built Environ2011;20(1):5–15.
Department of Health, UK: Letters from the Interim Chief Medical Officer and the Chief Nursing officer: Recognising Carbon Monoxide Poisoning – ‘Think CO’. PL/CMO/2008/8, PL/CNO/2008/8, UK, 2008.
12.
VerrierADelaunayCCoquetSThéaudinKCabotCGirardDDaoudiJde BelsF: Carbon monoxide poisoning episodes in metropolitan france in 2007: Bulletin Epidemiologique Hebdomadaire2010;1:1–5.
13.
SalamehSAmitaiYAntopolskyMRottDStalnicowiczR: Carbon monoxide poisoning in Jerusalem: epidemiology and risk factors: Clin Toxicol (Phila)2009;47(2):137–141.
14.
DuTZhangYWuJSWangHJiXXuTLiYXuLLewinMR: Domicile-related carbon monoxide poisoning in cold months and its relation with climatic factors: Am J Emergency Med2010;28(8):928–932.
15.
BrownTHolmesPHarrisonPTC: The applicability of epidemiological methods to the assessment of the risks to human health of indoor air pollution: an overview: Indoor Built Environ2010;19(3):311–326.
16.
MoralesEJulvezJTorrentMde CidRGuxensMBustamanteMKunzliNSunyerJ: Association of early-life exposure to household gas appliances and indoor nitrogen dioxide with cognition and attention behavior in preschoolers: Am J Epidemiol2009;169(11):1327–1336.
17.
TekbasOFGulecMOdabasiEVaizogluSAGulerC: Determination of carbon monoxide levels in coffee shops in Ankara: Indoor Built Environ2009;18(2):130–137.
18.
EMKillick: The acclimatization of the human subject to atmospheres containing low concentrations of carbon monoxide: J Physiol1936;87(1):41–55.
19.
PenneyDG: Hemodynamic response to carbon monoxide: Environ Health Perspect1998;77:121–130.
20.
HedbladBEngströmGJanzonEBerglundGJanzonL: COHb% as a marker of cardiovascular risk in never smokers: results from a population-based cohort study: Scand J Public Health2006;34(6):609–615.
21.
BellMLPengRDDominiciFSametJM: Emergency hospital admissions for cardiovascular diseases and ambient levels of carbon monoxide results for 126 united states urban counties, 1999-2005: Circulation2009;120(11):949–955.
22.
DEFRA: The Air Quality Strategy for England, Scotland, Wales and Northern Ireland, Vol. 2, HMSO, Norwich, July 2007.
23.
WHO: Carbon monoxide – Air Quality Guidelines for Europe; in WHO: Air Quality Guidelines for Europe, Copenhagen, Denmark, 1987, pp. 210–220.
24.
YuCCrumpD: Indoor environmental quality – standards for protection of occupational safety, health and environment: Indoor Built Environ2010;19(5):499–502.
London Ambulance Service, NHS Trust: A Feasibility Study into Pre-Hospital Carbon Monoxide Monitoring of Patients: Unpublished, 2009.
27.
CheeKJNilsonDPartridgeRHughesASunerSSucovAJayG: Finding needles in a haystack: a case series of carbon monoxide poisoning detected using new technology in the emergency department: Clin Toxicol (Phila)2008;46(5):461–469.
28.
HampsonNBScottKLZmaeffJL: Carboxyhemoglobin measurement by hospitals: implications for the diagnosis of carbon monoxide poisoning: J Emergency Med2006;31(1):13–16.
29.
DavutogluVGunayNKocogluHGunayNYildirimCCavdarMTarakciogluM: Serum levels of NT-ProBNP as an early cardiac marker of carbon monoxide poisoning: Inhalation Toxicol2006;18(2):155–158.
30.
KinoshitaTSugiharaSMatsusueEFujiiSAmetaniMOgawaT: Pallidoreticular damage in acute carbon monoxide poisoning: diffusion-weighted MR imaging findings: Am J Neuroradiol2005;26(7):1845–1848.
31.
LamKKFungHTKamCW: The severity and prognostic markers of 148 cases of carbon monoxide poisoning by burning charcoal: Hong Kong J Emergency Med2006;13(1):6–16.
CardellachFGarrabouGInorizaJMMartíMJOliuGLópezSt: Acute carbon monoxide poisoning: treatment with normobaric or hyperbaric oxygen and its correlation with mitochondrial complex IV activity from peripheral blood lymphocytes. Libro de resúmenes, 46th Society of Toxicology (SOT) Annual Meeting, EEUU:,Charlotte,2007.
34.
National Health Service: HTA programme: Systematic Review 2 – July 2008. The clinical and cost effectiveness of hyperbaric oxygen therapy: Quality Improvement, Scotland, 2008.
35.
SandersRWKatzKDSuyamaJAkhtarJO'TooleKSCorllDLadenburgerRN: Seizure during hyperbaric oxygen therapy for carbon monoxide toxicity: a case series and five-year experience: J Emergency Med2009; in press, doi:10.1016/j.jemermed.2008.12.017.
36.
WeaverLKValentineKJHopkinsRO: Carbon monoxide poisoning: risk factors for cognitive sequelae and the role of hyperbaric oxygen: Am J Respir Crit Care Med2007;176(5):491–497.
37.
ScheinkestelCDBaileyMMylesPSJonesKCooperDJMillarILTuxenDV: Hyperbaric or normobaric oxygen for acute carbon monoxide poisoning: a randomised controlled clinical trial: Med J Aust1999;170(5):203–210.
38.
WeaverLK: Hyperbaric oxygen in carbon monoxide poisoning; Letters – Authors of study clarify points that they made: Br Med J2000;321:109doi: 10.1136/bmj.321.7253.109.
39.
WolfSJLavonasEJSloanEPJagodaAS: Clinical policy: critical issues in the management of adult patients presenting to the emergency department with acute carbon monoxide poisoning: Ann Emergency Med2008;51(2):138–152.
40.
MathieuDNolfMDurocherASaulnierFFrimatPFuronDWattelF: Acute carbon monoxide poisoning. Risk of late sequelae and treatment by hyperbaric oxygen: J Toxicol Clin Toxicol1985;23(4–6):315–324.
41.
SmithJSBrandonS: Morbidity from acute carbon monoxide poisoning at three year follow up: Br Med J1973;1:318–321.
42.
BaroisAGrosbuisSGoulonM: Les intoxications aiguës par l'oxyde de carbone et les gaz de chauffage: Rev Prat1979;29:1211–1231, cited in WHO (1999).
43.
HSE: A review of carbon monoxide incident information for 2003/04, produced from the full investigation of incidents which had resulted from the use of piped natural gas and LPG within Great Britain, Health and Safety Executive, Research Report 439, HMSO, Norwich, 2006.
44.
HSE: A review of carbon monoxide incident information, for 2005/06, produced from the full investigation of incidents which had resulted from the use of piped natural gas and LPG, within Great Britain. Health and Safety Executive, RR634, HMSO, Norwich, 2008.
45.
SánchezBAÁlvarezCCÁlvarezCS: Carbon monoxide intoxication: Puesta al Dia en Urgencias, Emergencias y Catastrofes2005;6(2):91–98.
BasarabMLeonardiGSRugglesR: Developing best practice response to carbon monoxide incidents: a toolkit for health protection frontline staff: Chem Hazards Rep2008;13:14–17. Available at: http://www.hpa.org.uk/web/HPAwebFile/HPAweb_C/1222068844046.
50.
MandalSRugglesRMurrayVLeonardiGGoodfellowFSchweigerMBradleyN: Developing best practice response to carbon monoxide incidents: a toolkit for health protection frontline staff: Chem Hazards Rep2008;13:18–21. Available at: http://www.hpa.org.uk/web/HPAwebFile/HPAweb_C/1222068844046.
51.
UK CLG: Study of the provision of carbon monoxide detectors under the building regulations, BD 2754, 2009.
52.
CroxfordBHutchinsonELeonardiGSMcKennaLNicholsonLVolansGWilkinsonP: Real time carbon monoxide measurements from 270 UK homes: Proceedings of the A and WMA Indoor Environmental Quality: Problems, Research and Solutions Conference2006; 1:400–412.
53.
CroxfordB: Gas appliance check project: A report on a project funded by the UK Health and Safety Executive, 2006. Available at: www.hse.gov.uk/gas/domestic/uclgasfinal.pdf (accessed September 6, 2006)
54.
CroxfordBLeonardiGSKreisI: Self-reported neurological symptoms in relation to CO emissions due to problem gas appliance installations in London: a cross-sectional survey: Environ Health2008;7:34.
