Risk Analysis - Mercury in Liquefied Petroleum Gas

Inhalation of Mercury from Combusted LPG

The case that was analyzed is the risk to an individual from inhalation of mercury that originated in LPG burned in a cooking stove. The following rationale and assumptions were adopted.

• 1. It was assumed that the mercury species in combusted gas was elemental mercury. The species of mercury that exist in LPG combustion gases have not been determined. Mercury compounds in coal, for example, are mostly sulfides and when coal is burned, the combusted species include elemental mercury, mercuric oxides and some amount bound to particulates. Because the dominant species in LPG is elemental mercury, it was suspected and assumed that the species present in combustion gases is the elemental species also.



• 2. It was assumed in the following analysis that all of the mercury in the combusted LPG would be transferred to the atmosphere via combustion and thus available to be inhaled by an individual in proximity to the combustion source.



• 3. The conditions of exposure were considered uniform and constant, i.e. dynamic factors such as the effects of variations in climate on ventilation were not considered.



• 4. The case of LPG use in a temperate climate was examined, meaning that LPG would be typically used for cooking, not heating.



• 5. The situation chronic exposure (24 hour per day, 365 day per year) was considered for a person living in a residence and using a cooking stove routinely. Occupational exposures were not considered.



• 6. Dermal absorption of mercury was not considered as an exposure pathway.