It is the first project funded by the Goh Keng Swee Foundation, a private charitable organisation set up in the name of Singapore's former deputy prime minister by his wife Phua Swee Liang last November.

The idea is the brainchild of the Active Retirees' Association (ARA), a group set up in 2003 for those aged 50 and above, which organises voluntary activities for its more than 100 members.

ARA president Jackson Chia Sze Soon, 65, said its volunteers had noticed many seniors were burning joss sticks at home when volunteers were doing house visits for the elderly.

He said, 'Some of the flats are full of smoke and soot. These people are facing a risk but they are not aware of the risks.'

These dangers were highlighted in a study conducted by the National University of Singapore's (NUS) department of community, occupational and family medicine, and was reported in The Straits Times last August.

The study found that burning incense at home over long hours for more than 40 years significantly increased one's risk of contracting cancers in the upper respiratory tract, including cancers of the nose or sinuses, tongue, mouth and windpipe.

However, Mr Chia said, it was hard to persuade the elderly to open their doors and windows for ventilation: 'They are very reluctant to open the door; they don't want people to peep in.'

So, the association came up with the alternative of installing smoke absorbers.

Read the full report in Saturday's edition of The Straits Times.