Tam E K, Liu J, Bigby B G, Boushey H A
Cardiovascular Research Institute, University of California, San Francisco 94143-0130.
Am Rev Respir Dis. 1988 Dec;138(6):1559-64. doi: 10.1164/ajrccm/138.6.1559.
We examined whether brief exposures to moderately high concentrations of sulfur dioxide (SO2) causes acute increases in nasal symptoms and nasal resistance in subjects with chronic rhinitis. We studied 19 subjects with allergic rhinitis and 3 subjects with chronic intermittent rhinorrhea, nasal congestion, and sneezing without any other manifestation of allergy. We found that the change in nasal resistance and symptoms caused by nasal inhalation of 4 ppm of SO2 for 10 min was no greater than the changes caused by nasal inhalation of conditioned room air. In a second set of experiments, we examined whether allergic subjects with demonstrable bronchomotor responsiveness to SO2 also had nasal responsiveness to the gas. We studied 8 subjects with a history of both asthma and allergic rhinitis. Each subject developed symptoms of dyspnea or wheezing and an increase in specific airway resistance of at least 8 L x cm H2O/L/s after breathing 1 or 2 ppm of SO2 by mouthpiece at 20 L/min, and did not develop these changes after breathing room air under the same conditions. No subject, however, developed more nasal symptoms or a greater increase in nasal airway resistance after tidally breathing SO2 through the nose than after breathing room air, even when the concentration of SO2 delivered to the nose was double the concentration delivered through the mouthpiece to the lower airways. We conclude that brief exposure to SO2 at a concentration of 4 ppm or less is unlikely to cause significant nasal dysfunction in most subjects with chronic rhinitis, and that in subjects with both allergic rhinitis and asthma, responsiveness to SO2 is not uniform throughout the respiratory tract.
我们研究了短期暴露于中等高浓度的二氧化硫（SO₂）是否会导致慢性鼻炎患者的鼻部症状急性增加和鼻阻力升高。我们研究了19名变应性鼻炎患者和3名患有慢性间歇性鼻溢、鼻塞和打喷嚏但无任何其他变应性表现的患者。我们发现，经鼻吸入4 ppm的SO₂ 10分钟所引起的鼻阻力和症状变化并不比经鼻吸入经调节的室内空气所引起的变化更大。在第二组实验中，我们研究了对SO₂有明显支气管运动反应性的变应性受试者对该气体是否也有鼻反应性。我们研究了8名有哮喘和变应性鼻炎病史的受试者。每位受试者在以20 L/min的流速通过咬嘴经口呼吸1或2 ppm的SO₂后，均出现呼吸困难或喘息症状以及特定气道阻力至少增加8 L·cm H₂O/L/s，而在相同条件下呼吸室内空气时则未出现这些变化。然而，即使经鼻给予的SO₂浓度是经咬嘴给予下呼吸道的浓度的两倍，也没有受试者在经鼻潮式呼吸SO₂后比呼吸室内空气后出现更多的鼻部症状或更大的鼻气道阻力增加。我们得出结论，在大多数慢性鼻炎患者中，短期暴露于浓度为4 ppm或更低的SO₂不太可能导致明显的鼻功能障碍，并且在患有变应性鼻炎和哮喘的受试者中，对SO₂的反应性在整个呼吸道中并不一致。
