SODIUM METABISULFITE AND SO2 RELEASE - AN UNDER-RECOGNIZED HAZARD AMONG SHRIMP FISHERMEN

Since the introduction of sodium metabisulfite as a food preservative, it has been associated with several idiosyncratic reactions (eg, bron chospasm, oculonasal symptoms, and urticaria/angioedema) in sulfite-se nsitive individuals. The pathogenic mechanism of these reactions is no t yet understood. We report the case of two crewmen on a shrimp trawle r who were found dead in the ship's hold. Their deaths had occurred wh ile they were applying dry sodium metabisulfite, referred to as ''shri mp dip'' in the shrimping industry. Postmortem examinations showed dif fuse pulmonary edema consistent with death secondary to asphyxia. Asso ciated findings were visceral congestion. Although it is possible to m easure death from sodium metabisulfite with available records, its pot ential morbidity cannot be estimated. It is known that sodium metabisu lfite can react with acids and water, releasing toxic sulfur dioxide ( SO2) gas. In addition, SO2 gas reacts with respiratory tissue forming sulfurous acid, and inducing a pulmonary reaction causing hypoxemia. F urthermore, sodium metabisulfite, compared with sodium bisulfite, has a much greater propensity to release SO2 gas. We conclude that there i s a need for improved education regarding the potential side effects o f sodium metabisulfite, thus eliminating needless occupational morbidi ty and mortality.