I was shocked to read Minister Leslie Miller’s statement that switching BEC’s primary fuel from diesel to HFO (Bunker C) would reduce electricity bills by 30%, shocked because the statement fails to mention the health and environmental costs associated with bunker C fuel. It was even more disturbing to read that the use of bunker C for power generation was supported by Abaco’s chief counselors.
The choice of Bunker C to fuel the power plant is understandable when considered solely from an economic standpoint. However, it is important to also recognize problems associated with the shipping, handling and combustion of this fuel, which may, in turn, have important deleterious consequences for the environment and human health. These stem from the nature and components of Bunker C fuel.
Bunker C fuel is a witch’s brew of toxic chemicals. These include asphaltenes, naphthalenes, sulfur, nitrogen-containing compounds and heavy metals. Toxins present include dioxin and furans – among the most toxic substances known. Polyaromatic hydrocarbons (PAH’s) which include benzpyrene, benzanthracene and phenanthracenes, recognized human carcinogens, are present in Bunker C oil at levels up to 5% in total. The refining process of crude oil concentrates these substances in the heavy fractions such as Bunker C which may contain levels up to 15 times greater than those found in crude oil.
PAH’s do not break down easily during combustion and variable concentrations may be present in emissions. PAH’s are persistent and when adsorbed onto soot may contaminate properties miles from the power plant and find their way into ground water.
The sulfur content of fossil fuels serves as a marker for chemicals which are dangerous to human health and the environment. In the U.S. the sulfur content of automotive diesel is limited to 15 parts per million (ppm). According to the U.S. Environmental Protection Authority, bunker C typically contains 27,000 ppm of sulfur. It is an indication of the concern with which authorities regard the safety of heavy oil fuels that the U.S. introduced an environmental control act which prohibits ships burning fuel oil with sulfur content greater than 1,000 ppm within 200 nautical miles of U.S. coasts. Similar regulations have been enacted by countries bordering the North and Baltic Seas and, of course, Bunker C is banned within those countries.
Operating a power plant using Bunker C fuel can be technically difficult and hazardous from the standpoint of human health and environmental protection. This is so because the composition of Bunker C fuel is complex, concentrations of toxins present in this fuel are high, and complete destruction of the toxic components of Bunker C during power plant operation cannot be assumed. The extent to which destruction occurs depends on the particular fuel being used, the use of additives that enhance combustion, the efficiency of the combustion, and the use of scrubbers to eliminate toxic components from the emissions.
Material Safety Data Sheet information indicates that exposure to Bunker C fuel per se is toxic to the skin and eyes. If, in the unfortunate instance that Bunker C contaminates the marine environment, the toxic components of this fuel persist in marine plant life, vertebrates and invertebrates, and eventually pose a hazard to human health when the latter are ingested.
In summary, there is a real possibility that the use of Bunker C oil in the power plant will result in the contamination of fish and other marine organisms and the land environment with trace, albeit critical, levels of human carcinogens. In this instance, it would be prudent for residents of islands that depend on rain catchment for drinking and cooking water to install reverse osmosis filtration for water supplies.
-Clifford I. Chappel, D.V.M., Ph.D.