Salome C M, Brown N J, Marks G B, Woolcock A J, Johnson G M, Nancarrow P C, Quigley S, Tiong J
Institute of Respiratory Medicine, Royal Prince Alfred Hospital, Sydney, NSW, Australia.
Eur Respir J. 1996 May;9(5):910-8. doi: 10.1183/09031936.96.09050910.
Nitrogen dioxide (NO2) is one of a number of nitrogen compounds that are by-products of combustion and occur in domestic environments following the use of gas or other fuels for heating and cooking. In this study, we examined the effect of two levels of NO2 on symptoms, lung function and airway hyperresponsiveness (AHR) in asthmatic adults and children. In addition, in the same subjects, we examined the effects of the same levels of NO2 mixed with combustion by-products from a gas space heater. The subjects were nine adults, aged 19-65 yrs, and 11 children, aged 7-15 yrs, with diagnosed asthma which was severe enough to require daily medication. All subjects had demonstrable AHR to histamine. Exposures were for 1 h on five separate occasions, 1 week apart, to: 1) ambient air, drawn from outside the building; 2) 0.3 parts per million (ppm) NO2 in ambient air; 3) 0.6 ppm NO2 in ambient air; 4) ambient air+combustion by-products+NO2 to give a total of 0.3 ppm; and 5) ambient air+combustion by-products+NO2 to give a total of 0.6 ppm. Effects were measured as changes in lung function and symptoms during and 1 h after exposure, in AHR 1 h and 1 week after exposure, and in lung function and symptoms during the week following exposure. Exposure to NO2 either in ambient air or mixed with combustion by-products from a gas heater, had no significant effect on symptoms or lung function in adults or in children. There was a small, but statistically significant, increase in AHR after exposure to 0.6 ppm NO2 in ambient air. However, there was no effect of 0.6 ppm NO2 on AHR when the combustion by-products were included in the test atmosphere nor of 0.3 ppm NO2 under either exposure condition. We conclude that a 1 h exposure to 0.3 or 0.6 ppm NO2 has no clinically important effect on the airways of asthmatic adults or children, but that 0.6 ppm may cause a slight increase in airway hyperresponsiveness.
二氧化氮（NO₂）是多种氮化合物之一，这些氮化合物是燃烧的副产品，在使用燃气或其他燃料进行取暖和烹饪的家庭环境中会出现。在本研究中，我们研究了两种浓度的NO₂对哮喘成人和儿童的症状、肺功能及气道高反应性（AHR）的影响。此外，在相同的受试者中，我们研究了相同浓度的NO₂与燃气取暖器燃烧副产品混合后的影响。受试者为9名年龄在19至65岁之间的成年人以及11名年龄在7至15岁之间的儿童，他们均被诊断患有哮喘，严重程度足以需要每日用药。所有受试者对组胺均有明显的气道高反应性。在五个不同的场合，每次暴露1小时，间隔1周，分别暴露于：1）从建筑物外抽取的环境空气；2）环境空气中0.3 ppm的NO₂；3）环境空气中0.6 ppm的NO₂；4）环境空气 + 燃烧副产品 + NO₂，总量达0.3 ppm；5）环境空气 + 燃烧副产品 + NO₂，总量达0.6 ppm。通过测量暴露期间及暴露后1小时的肺功能和症状变化、暴露后1小时及1周的气道高反应性变化以及暴露后一周内的肺功能和症状变化来评估影响。暴露于环境空气中的NO₂或与燃气取暖器燃烧副产品混合的NO₂，对成人或儿童的症状或肺功能均无显著影响。暴露于环境空气中0.6 ppm的NO₂后，气道高反应性有小幅但具有统计学意义的增加。然而，当测试环境中包含燃烧副产品时，0.6 ppm的NO₂对气道高反应性没有影响，且在任何一种暴露条件下，0.3 ppm的NO₂也没有影响。我们得出结论，暴露于0.3或0.6 ppm的NO₂ 1小时对哮喘成人或儿童的气道没有临床重要影响，但0.6 ppm可能会导致气道高反应性略有增加。
