Mercury from crematoriums: human health risk assessment and estimate of total emissions in British Columbia.

OBJECTIVES Mercury occurs in the environment as a result of natural processes and human activities, including when individuals with amalgam dental fillings are cremated. This work aimed to estimate the quantity of mercury emitted to the atmosphere from crematoriums in British Columbia (BC) and assess the human health risk. METHODS A BC-specific emissions factor for mercury from crematoriums was developed and applied to an estimate of the quantity of mercury released annually to the atmosphere from crematoriums. The maximum ground-level mercury vapour concentrations resulting from crematorium emissions were estimated. RESULTS In BC, it is estimated that approximately 1.20 g of mercury is emitted to the atmosphere per body cremated and about 30,000 cremations were conducted in the province in 2016. It is estimated that almost 36 kg of elemental mercury was released to the atmosphere as a result. The maximum estimated peak short-term and long-term average ground-level mercury vapour concentrations associated with crematorium emissions were 0.31 μg/m3 and 7.9 × 10-3 μg/m3 respectively, which are far lower than the reference concentration (hazard quotient of less than 1). CONCLUSION Mercury from crematoriums accounts for more than 7% of total mercury emissions to the atmosphere in BC, but risk assessment found no indication that ground-level exposures to elemental mercury vapour from crematoriums poses a significant risk to human health. If the number of cremations increases, it might reach considerable levels, highlighting the need for developing a national plan similar to other countries.