Once again the "technical-wool" is being pulled over the untrained citizens eyes; this time in the "clean-fuel program" article (Part I, Jan. 5). There is no such thing as fuel that burns cleanly. Such terminology is a contradiction in terms. All fuel processes in use today use air as their source of oxygen and 80% of that air is nitrogen. Consequently, all combustion processes spew out oxides of nitrogen, more or less, depending upon the temperature of combustion. This applies to such fuels as hydrogen, alcohol, methanol and natural gas as well as gasoline, diesel and fuel oil.
The argument the AQMD uses that 95% of the hydrocarbon smog component is from human combustion processes has long been a very debatable point. Garden odors are unburnt hydrocarbons. Besides that, exactly how much hydrocarbon smog is required for the photo-chemical smog process to produce its damaging components has not been determined. What is know, however, is that oxides or nitrogen or NOX are all created by human combustion processes and that all serious health hazards, i.e. ozone and smog-produced carcinogens are the result of NOX-HC reactions in sunlight.
The point here is that all combustion processes create oxides of nitrogen and it is these products that form the basis of all serious health hazards resulting from smog. Carbon monoxide and unburnt hydrocarbons by themselves are not a serious problem in the concentrations normally occurring. It is time the AQMD faced up to the fundamental chemistry involved and did something about NOX rather than obfuscate the issue in favor of other more easily handled aspects which also contribute little, if anything, toward solving the essential smog problem.
SHELDON C. PLOTKIN
Southern Calif. Federation of Scientists