Mercury emissions from crematoria

A previous preliminary pilot study indicated that concentrations of mercury in crematoria soils might be significantly higher than controls. The source of the contamination has been assumed to be dental amalgam from cremated cadavers. Amalgam fillings contain 50% mercury, which under cremation conditions is totally vaporised and emitted from the stack either as the metallic vapour or in the oxidised form. Mercury is a cumulative poison with varying biochemical effects according to concentration and species, inter alia. Although much research has centred on the affects of dental amalgam in the living, the problems arising from disposal in the dead have been largely overlooked. This study investigated mercury emissions from crematoria by means of soil and air sampling programmes. The extent of exposure to the mercury by the crematoria workers was then determined by a hair-sampling programme. The soil monitoring and analysis programme involved five crematoria and measurements were made both by using a mercury vapour meter and flameless atomic absorption techniques. Levels in each case were significantly higher than controls and gave good overall correlation with cremation output. Air measurements varied and in one case exceeded the occupational exposure standard. In all cases the levels exceeded a proposed ambient air level goal of 1 µg m-3. Hair levels in crematorium workers were significantly in excess of controls (p<0.05). Three percent of workers had levels in excess of 6 ppm, which is considered the tolerable’ limit. The risk to workers and the surrounding population, in particular children, including the unborn, may be too great to be ignored. The Environmental Protection Act, in its Process Guidance Note for Crematoria: PG 5/2 (91), failed to give consideration to mercury emissions; the use of control procedures should be addressed to modify further emissions.