Sulphur dioxide is irritating to the eyes, throat and respiratory tract. Short-term overexposure causes inflammation and irritation, resulting in burning of the eyes, coughing, difficulty in breathing and a feeling of chest tightness. Asthmatic individuals are especially sensitive to SO₂ (Baxter, 2000) and may respond to concentrations as low as 0.2-0.5 ppm. (quoted from ivhhn.org).
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二酸化硫黄への呼吸器曝露による健康への影響

(Baxter, 2000; Nemery, 2001; NIOSH 1981; Wellburn, 1994)

Exposure limits (ppm)	Exposure limits mg/m3	Equivalent in USEPA AQI	Health Effects
1-5	2.8-14.1	1 - 7	Threshold for respiratory response in healthy individuals upon exercise or deep breathing
3-5	4 - 7		Gas is easily noticeable. Fall in lung function at rest and increased airway resistance
5	14.1	7	Increased airway resistance in healthy individuals
6	17	8	Immediate irritation of eyes, nose and throat
10	28	14	Worsening irritation of eyes, nose and throat
10-15	28-42	14-21	Threshold of toxicity for prolonged exposure
20+	56+	28+	Paralysis or death occurs after extended exposure
150	420	134	Maximum concentration that can be withstood for a few minutes by healthy individuals