Endogenous sulfite is generated as a consequence of the body’’s
normal processing of sulfur-containing amino acids. In addition,
as discussed below, sulfite can be produced by neutrophils.
Sulfites occur as a consequence of fermentation and also naturally
in a number of foods and beverages. As food additives,
sulfating agents were first used in 1664, and approved for use in
the United States in the 1800s. Sulfite is also noted as a water
treatment additive, for example, to control oxygen levels in
power plant boiler water. Further, sulfur dioxide is acommonair
pollutant produced by numerous processes (burning sulfurbearing
coal, smelting sulfide ores, etc.), and may enter the body
via inhalation. Sulfur dioxide has been reported to react with
water in the ambient air and in the respiratory tract’s mucous
membranes to form sulfite and bisulfite ions.
