The major air pollutants of the 1952 incident were primairly sulfur dioxide (SO₂), along with carbon monoxide (CO), nitrogen oxides (NO_x), and ozone (O₃). These pollutants accounted for about 98% of air pollution then (and now as well) worldwide (see e.g., Costa and Amdur, 1996; Elsom, 1996).

SO₂ is an intermediate in the formation of sulfuric acid. This irritant affects predominantly the upper airway, and is a common air pollutant produced by the combustion of pyrite (FeS₂) available in coal and fuel oil. These sources add millions of tons of SO₂ to the global atmosphere each year. Acid rain results if the pH of the deposition is lowered by this air pollutant.

CO is a potent chemical asphyxiant, in that it can readily bind to hemoglobin to prevent oxygenation of the blood for systemic transport. The two most common oxides of nitrogen are nitric oxide (NO) and nitrogen dioxide (NO₂), the latter of which can be readily converted from the former through the so-called photochemical smog formation (2NO + O₂ Ž 2NO₂). This conversion consists of complex chain reactions involving light energy and unstable reactive intermediate species. Inhalation of NO₂ causes severe irritation of the innermost parts of the lungs resulting in primarily pulmonary edema and fatal bronchiolities fibrosa obliterans (Manahan, 1989). O₃ is a reactive and toxic form of elemental oxygen. The production of pollutant atmospheric ozone occurs readily under the conditions of photochemical smog formation discussed above.