Irish Roman Catholics have been warned that churchgoing could pose a threat to their health because incense contains potentially dangerous chemicals.
A minister in the Dublin government has said that altar boys and girls could be particularly at risk.
Dr Jim McDaid, a transport minister, highlighted the threat in the context of plans to ban smoking in the workplace from the start of next year, which he supports.
Dr McDaid, who once ran a medical practice, said he was not against the use of incense but added: "We all know that carbon is a carcinogenic agent and, wherever you have smoke, you are actually looking at carbon molecules. And wherever you have carbon molecules and happen to be inhaling them, then there is that chance that you will be doing damage.
"This [incense burning] is something I have mentioned in the past to a number of clergy."
A spokesman for the Dublin archdiocese said: "Obviously anything that sends a cloud of smoke into a child's face is something we would be concerned about."
She added, however, that while incense had been widely used in the past during Benediction and High Mass, nowadays it was most often used at funerals.
Fr John McCann, the Master of Ceremonies to the Archbishop of Dublin, said he believed there was growing awareness about the potential effects of incense. He added: "In a small church building you have to be aware, particularly if there are servers suffering from asthma."