Mercury in smoke from biomass fires

Litter and green vegetation were collected in 7 locations in the contiguous United States, analyzed for mercury, and burned under controlled condition s at the US Forest Service Fire Science laboratory in Missoula, MT. Among f uels, leaf and 3needle litter contained the highest concentration (up to 71 ng/g on dry weight) of mercury. The combustion of litter and green vegetati on resulted in essentially complete release of mercury stored in the fuel. Mercury is emitted primarily as elemental mercury, > 95% for most bums, wit h particulate mercury (TPM) accounting for the remainder. From the laborato ry experiments we project that mercury emitted from temperate/boreal forest fires and from all biomass burning is an important source components for t he atmospheric mercury budget.