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Letter: Danger of Woodstove Soot

To the Editor:

Now that winter is fast approaching, Upper Valley residents who burn wood for heat need to be aware of the danger of fireplace and woodstove soot, tars and creosote. These black combustion materials contain carcinogenic polycyclic aromatic hydrocarbons.

As first observed by the London physician Dr. Percivall Pott in 1775, exposure to fireplace soot and tars led to scrotal cancer in chimney sweeps, the first documented occupational cancer. These typically young boys cleaned the fireplaces and chimneys from the inside, and, lacking good personal hygiene, they developed this often-fatal skin cancer from their soot-covered clothes. Much later, studies in 1915-1925 by Japanese and English chemists clearly demonstrated that soot and tars cause skin cancer in rabbits, mice and other animals. In 1933, one of the causative chemicals, benzo[a]pyrene, was isolated from coal tar and found to be a supremely deadly carcinogen. We know now that this prototypical compound, along with myriad other carcinogenic polycyclic aromatic hydrocarbons, form when any organic (carbon-containing) material is burned, including tobacco, fossil fuels, garbage, forests, even food. Indeed, benzo[a]pyrene may be a cause of lung cancer in humans.

One needs to avoid contact with the black soot when removing the ashes from the fireplace or woodstove — prevention by avoidance of contact. I would also use care when handling the ashes. Leave the actual chimney cleaning to the experts.

Gordon W. Gribble

Professor of organic chemistry, Dartmouth College