Crematoria have cut pollutants
Crematoria may be ordered to take action to reduce the amount of mercury from tooth fillings that is released into the atmosphere when bodies are cremated.
The Department for Environment, Food and Rural Affairs has launched a three-month consultation exercise to examine the need for action.
Mercury is a highly toxic heavy metal that cannot be degraded into harmless products.
Exposure to the metal has been linked to damage to the brain and nervous system. It has also been linked to fertility problems.
It is estimated that crematoria release up to 16% of the UK's total mercury emissions.
This despite a cut in emissions from 44.9 tonnes to 8.8 tonnes a year between 1970 and 2000.
The Federation of British Cremation Authorities is concerned that new measures could force the closure of many crematoria.
It says there is insufficient evidence that mercury is emitted in any significant quantities during the cremation process.
Paul Stubbs, technical officer for the federation, told BBC News Online that up to 25% of crematoria would not be in a position to install the air filtration equipment that would be required to reduce mercury emissions.
He said in many cases this would require crematoria to build extensions, which was not possible if the building was already surrounded by graves which could not be disturbed.
Mr Stubbs said tests carried out on crematoria workers had shown no evidence of health problems related to exposure to mercury.
"I have worked in the business for 30 years, and I have suffered nothing untoward," he said.
At present, pacemakers, or other devices that could potentially cause an explosion during the cremation process are removed before the body arrives at the crematorium.
But tooth fillings are left in place.
Crematoria have already spent between £125m and £150m to reduce air pollution during the 1990s.
This was to comply with targets on pollutants such as particulates, hydrogen chloride, carbon monoxide and dioxins.