Sulfur dioxide tranfers via inhalation reported in lymphocytes from 42 workers at an Indian fertilizer plant who were exposed to an average concentration of 41.7 mg/m3 (15.92 ppm) of sulfur dioxide (Yadav and Kaushik 1996).
Generally, asthma patients suffer with sulfite sensitivity who are steroid dependent. Sulfite sensitivity has also been related to allergy. It is generally not found in persons who are both non-allergic and non-asthmatic. Even in patients who are sensitive to inhaled sulfites, the ingestion of foods containing sulfite (like beer and wine) may not cause a reactions, since the reaction depends on a number of factors.
The mechanism by which inhaled sulfites trigger bronchospasm. It may be due to the formation of sulphur dioxide within the airways that affects the airway mucosa, then activation extends the allergic antibody (IgE) underlying release of histamine.
Some asthma medications contain sulfites. Sulfite can suffer bronchospasm in a dose-related manner. In particular, both isoproterenol and isoetharine are contained sulfite in unacceptable dosage to trigger bronchospasm in most patients with asthma. Bronchospasm can also surge in those with asthma who are even not sulfite sensitive.
Furthermore, molybdenum deficiency was detected in most patients relating to legumes deficiency such as soybeans, navy beans and lentils that some people in developed countries avoid . Molybdenum is the trace element contained in the enzyme sulfite oxidase which detoxifies sulfite to the inert and harmless sulfate (Pfeiffer, 1983; Sohler, 1983). In addition to molybdenum, some pantothenic acid, found to have a significant protective action against sulfur dioxide poisoning (Hoetzel, 1961) would also be useful.
Usual symptoms which have been detected as commonly experienced by sulfite-sensitve individuals include wheezing, labored breathing, chest-tightness, cough, faintness, extreme shortness of breath, respiratory arrest, loss of consciousness, blue discoloration of skin, flushing, angioedema, hives, laryngeal edema, hypotension, generalized itching, contact dermatitis, episodic swelling of hands, feet and eye areas, mood changes, clammy skin, abdominal cramps, nausea, diarrhea and anaphylactic shock.
Anaphylaxis can result in collapse of circulatory system and throat swelling, then death would occur. In the United States, including six death cases was recorded. While in Canada, 10 sulphite-related adverse reactions and one death, thought to be sulphite related (Yang and Purchase, 1985).