Health Effects of TRS Compounds, 1995 Environmental Conference Proceedings

Vickie L. Tatum

NCASI

The reduced sulfur gases hydrogen sulfide, methyl mercaptan, dimethyl disulfide and dimethyl sulfide, are produced in kraft pulp mills during pulp digestion and may be released, generally at low levels, into the atmosphere. Although high concentrations of H2 S are acutely toxic, exposure to low (less than 20 ppm) concentrations of H2 S is not generally associated with significant adverse health effects. Based upon animal studies, both methyl mercaptan and dimethyl disulfide appear to be somewhat less toxic than hydrogen sulfide, but produce similar effects, while dimethyl sulfide is about 100 times less toxic. Epidemiological studies overall have not demonstrated significant health effects or increased risk of cancer in kraft pulp mill workers or mill community residents. Based on known mechanisms of toxicity of reduced sulfur compounds, it appears unlikely that any adverse health effects would result from exposures to current ambient air levels of reduced sulfur gases within kraft pulp mills or surrounding communities. However, some individuals have associated minor physical symptoms with exposure to low levels of reduced sulfur gases. A number of non-physiological odor-related mechanisms are suggested as potential explanations for these reported effects.