A study by Liverpool John Moores University (LJMU) has warned people of the dangers of carbon monoxide (CO).

The research found that 120 homes in Liverpool and Coventry contained high levels of the substance, despite inhabitants being unaware of its presence.

Dr Andrew Shaw, lead academic on the study for LJMU’s built environment and sustainable technologies (BEST) research institute, said that there is a significance risk of the number of CO-related incidents increasing in homes.

"The longer-term data loggers showed that there is a significant presence of low-level CO in homes that may not trigger a CO alarm but could still potentially lead to long-term health problems," Dr Shaw explained.

These findings come after Wayne Marshall, a builder from Seven Sisters, was prosecuted by the Health and Safety Executive after carrying out inefficient chimney repairs that led to a carbon monoxide leak.

Mr Marshall was assigned to fix the joint chimney in March 2010.