by Angela K. Spivey, University of North Carolina School of Medicine
Suicide rates two and three times the average in North Carolina counties may be linked to releases of hydrogen sulfide and other airborne chemicals from a nearby paper mill and possibly other industrial sites, according to a University of North Carolina at ChapelHill psychiatrist. The findings of a new study were presented in November to the US Psychiatric and Mental Health Congress.
The study’s lead author is Dr. Richard H. Weisler, adjunct professor of psychiatry at UNC’s School of Medicine, adjunct assistant professor of psychiatry at Duke University Medical Center and volunteer with the Blue Ridge Environmental Defense League, or BREDL.
“We clearly know there have been increases in suicides during this time period when there were also operational changes at the paper mill,” said Weisler. “The 1997 spike in suicides in Haywood County corresponded to a switch to Bleach Filtrate Recycle in late 1996. Whether there is a connection between the increased suicides and operational changes has yet to be determined.”
The Haywood County mill uses Bleach Filtrate Recycle, or BFR, to help remove chlorine and other toxins from the waste discharged into the Pigeon River. But Weisler and co-authors said they questioned whether or not a cleaner river comes at the cost of dirtier air.
“The burning of chlorinated compounds that BFR potentially entails, as well as a possible increase in plant volume, may have led to increased releases of dioxins and other harmful compounds into the air,” Weisler said. “The switch to BFR, which involves burning of black liquor, may have resulted in an increase in air quality problems.”
“Black liquor” is chemical and wood waste produced when turning wood into paper pulp. Some paper mills, including the Haywood County mill, burn black liquor to produce electricity. The Haywood County mill has reported releases of many chemicals, including more than 93,000 pounds of hydrogen sulfide in 2003. Studies of industries such as asphalt plants, paper mills and sewage treatment plants have shown that exposure to occupational levels of hydrogen sulfide (10 parts per million for a 10-minute ceiling) can result in nervousness, mania, dementia and violence, Weisler said. It is unknown whether levels lower than those to which nearby residents are exposed also would influence brain chemistry. “I think it has to be explored,” Weisler added.
In animal studies, hydrogen sulfide has been shown to be a neurotoxin, altering levels of brain chemicals such as serotonin, norepinephrine, dopamine, aspartate, GABA and glutamate, the authors reported. “We speculate that hydrogen sulfide may serve as a marker for other potentially neurotoxic compounds being released in this mountain valley,” Weisler said.
Other chemical releases reported by the paper mill include carbon disulfide, dimethyl disulfide, dimethyl sulfide and methyl mercaptan.
“We hope there will be relevant and sensitive air monitoring, as well as a whole reassessment of whether or not burning the black liquor and using Bleach Filtrate Recycle is really the best approach to clean up the Pigeon River,” Weisler said.
—University of North Carolina School of Medicine News Release, November 2005 h t t p : / / w w w . u n c . e d u / n e w s / a r c h i v e s / n o v 0 5 / haywood110705.html
[From WS November/December 2005]