A Short History of Hydrogen Sulfide
From the sewers of Paris to physiological messenger
In 1713, a remarkable Italian physician named Bernardino Ramazzini published De Morbis Artificum, or Diseases of Workers. In Chapter 14, titled “Diseases of Cleaners of Privies and Cesspits,” he describes a painful inflammation of the eyes which was common among such workers. The inflammation often led to secondary bacterial invasion, and sometimes to total blindness. Displaying amazing insight, Ramazzini hypothesized that when the cleaners disturbed the excrement in the course of their work, an unknown volatile acid was produced, which was irritating to the eyes. It was also at least partially responsible for the odor of excrement, and it is now known to be generated wherever organic matter undergoes putrefaction.
Ramazzini further postulated that that same acid was causing copper and silver coins which the workers had in their pockets to turn black on their surfaces—an eerie resonance with the phenomena recently observed by U.S. homeowners. Around 1777, a series of accidents—some of them fatal—began to occur in Paris due to a gas emanating from its sewer system. The commission appointed to study the cases made its findings public in 1785. The report described two distinct types of poisonings: a mild form involving inflammation of the eyes and mucous membranes as already described by Ramazzini, and a severe form that was characterized by a fulminating (rapidly developing) asphyxia. It is little wonder that the French Romantic writer Victor Hugo (1802–1885) referred to the Parisian sewers as “the intestine of the Leviathan.” Many years were to pass, however, before chemical analyses would establish the presence of hydrogen sulfide in the sewers and implicate it as the cause of the accidents.
The history of exposures has focused on sewers and the workplace, but the corrosive effects of hydrogen sulfide are common knowledge in Rotorua, New Zealand, which was built over centuries in a geothermally active area. The constant exposure to low, environmental levels of hydrogen sulfide produces such damage even as residents enjoy spas, indoor heating and cooking with the hot gases.
Today, the American Conference of Industrial Hygienists has set the so-called threshold limit value for its presence in the workplace at 10 parts per million (ppm) of hydrogen sulfide in air for eight hours a day, five days a week over a working lifetime. The U.S. National Institute for Occupational Safety and Health estimated in 1977—some 200 years after the Paris accidents—that 125,000 workers in at least 77 occupations, including drilling for petroleum, tanneries and the paper industry, may be at risk of exposure to hydrogen sulfide.