Department of Occupational and Environmental Health, University of Iowa, Iowa City, Iowa.
Social & Scientific Systems, Inc., Durham, North Carolina.
Am J Respir Crit Care Med. 2019 Sep 15;200(6):712-720. doi: 10.1164/rccm.201809-1733OC.
House endotoxin and ambient air pollution are risk factors for asthma; however, the effects of their coexposure on asthma are not well characterized. To examine potential synergistic associations of coexposure to house dust endotoxin and ambient air pollutants with asthma outcomes. We analyzed data of 6,488 participants in the National Health and Nutrition Examination Survey 2005-2006. Dust from bedding and bedroom floor was analyzed for endotoxin content. The Community Multiscale Air Quality Modeling System (CMAQ) and Downscaler Model data were used to determine annual average particulate matter ≤2.5 μm in aerodynamic diameter (PM), ozone (O), and nitrogen dioxide (NO) exposures at participants' residential locations. The associations of the coexposures with asthma outcomes were assessed and tested for synergistic interaction. In adjusted analysis, PM (CMAQ) (odds ratio [OR], 1.12; 95% confidence interval [CI], 1.07-1.18), O (Downscaler Model) (OR, 1.07; 95% CI, 1.02-1.13), and log NO (CMAQ) (OR, 3.15; 95% CI, 1.33-7.45) were positively associated with emergency room visits for asthma in the past 12 months. Coexposure to elevated concentrations of house dust endotoxin and PM (CMAQ) was synergistically associated with the outcome, increasing the odds by fivefold (OR, 5.01; 95% CI, 2.54-9.87). A synergistic association was also found for coexposure to higher concentrations of endotoxin and NO in children (OR, 3.45; 95% CI, 1.65-7.18). Coexposure to elevated concentrations of residential endotoxin and ambient PM in all participants and NO in children is synergistically associated with increased emergency room visits for asthma. Therefore, decreasing exposure to both endotoxin and air pollution may help reduce asthma morbidity.
住宅内的内毒素和环境空气污染是哮喘的危险因素；然而，它们的共同暴露对哮喘的影响尚未得到很好的描述。为了研究住宅灰尘内毒素和环境空气污染物共同暴露与哮喘结果之间可能存在的协同关联。我们分析了 2005-2006 年全国健康和营养调查的 6488 名参与者的数据。对被褥和卧室地板的灰尘进行了内毒素含量分析。采用社区多尺度空气质量模型系统（CMAQ）和降尺度模型数据，确定了参与者居住地点的年平均可吸入颗粒物（PM）、臭氧（O）和二氧化氮（NO）暴露值。评估了共同暴露与哮喘结果的关联，并对协同作用进行了检验。在调整分析中，PM（CMAQ）（比值比[OR]，1.12；95%置信区间[CI]，1.07-1.18）、O（降尺度模型）（OR，1.07；95%CI，1.02-1.13）和 log NO（CMAQ）（OR，3.15；95%CI，1.33-7.45）与过去 12 个月内因哮喘急诊就诊呈正相关。住宅内灰尘内毒素和 PM（CMAQ）浓度升高的共同暴露与该结果呈协同关联，使患病几率增加五倍（OR，5.01；95%CI，2.54-9.87）。在儿童中，还发现了较高浓度的内毒素和 NO 共同暴露的协同关联（OR，3.45；95%CI，1.65-7.18）。所有参与者住宅内的内毒素和环境 PM 浓度升高，以及儿童体内的 NO 浓度升高，与哮喘急诊就诊次数增加呈协同关系。因此，降低内毒素和空气污染暴露可能有助于降低哮喘发病率。
