ABSTRACT
In order to determine whether short-term World Health Organization (WHO) guideline limits for carbon monoxide (CO) are exceeded in the home environment, a number of sensors were constructed capable of real-time measurement. These were deployed for a period of 7 days to continuously monitor CO concentrations in 44 non-smoking households using either gas, coal, electricity, liquid propane gas, or oil for heating fuel in South Wales. The mean environmental concentrations over the period monitored were less than 1 p.p.m and WHO short-term limits were not exceeded in any household. In another 20 homes containing a smoker the mean concentrations measured over a period of 2 days ranged from 0.1 to 21 p.p.m and WHO short-term limits were exceeded in one household.