Hyvärinen A, Roponen M, Tiittanen P, Laitinen S, Nevalainen A, Pekkanen J
Department of Environmental Health, National Public Health Institute, Kuopio, Finland.
Indoor Air. 2006 Feb;16(1):20-7. doi: 10.1111/j.1600-0668.2005.00392.x.
Exposure to farming environment in early life has been associated with lower risk for allergic diseases possibly caused by increased exposure to endotoxin. The aims of this study were to compare the reproducibility of different sampling methods for endotoxin, and to determine whether environmental characteristics have different effect on endotoxin levels of different sample types. The reproducibility of sampling methods (bed dust, floor dust, vacuum cleaner dust bag dust, settled dust and air samples) was studied with repeated sampling (five visits during 1 year) in five farming and five urban homes. To examine determinants of endotoxin for different types of dust sample, sampling was conducted once in 12 farming and 17 urban homes. Endotoxin was analyzed using Limulus Amebocyte Lysate assay. Bed dust samples had the best reproducibility (intraclass correlation, ICC=66%), but the difference between farming and non-farming homes was not clear with this sample type. The reproducibility of floor (ICC=52%) and settled dust (ICC=51%) was moderate. With these sample types the difference between farming and non-farming homes was clear. Settled dust had some seasonal variation. Based on this study, the best compromise for sampling for endotoxin appears to be floor dust sample followed by bed and settled dust samples. Practical Implications Endotoxins have been widely measured, even though the validity of different sample types to reflect the endotoxin exposure level of an indoor environment is poorly known. This study shows that bed dust samples have the best reproducibility, but they do not reflect the differences in exposure due to environmental factors such as farming. Floor dust samples with moderate reproducibility may be the best choice for sampling of endotoxin in large field studies.
早年接触农业环境与过敏性疾病风险降低有关，这可能是由于内毒素暴露增加所致。本研究的目的是比较不同内毒素采样方法的可重复性，并确定环境特征对不同样本类型的内毒素水平是否有不同影响。在五个农业家庭和五个城市家庭中，通过重复采样（一年中进行五次访问）研究了采样方法（床尘、地板尘、吸尘器集尘袋灰尘、沉降灰尘和空气样本）的可重复性。为了研究不同类型灰尘样本中内毒素的决定因素，在12个农业家庭和17个城市家庭中进行了一次采样。使用鲎试剂法分析内毒素。床尘样本的可重复性最佳（组内相关系数，ICC = 66%），但这种样本类型在农业家庭和非农业家庭之间的差异不明显。地板尘（ICC = 52%）和沉降灰尘（ICC = 51%）的可重复性中等。对于这些样本类型，农业家庭和非农业家庭之间的差异很明显。沉降灰尘有一些季节性变化。基于本研究，内毒素采样的最佳折衷方案似乎是地板尘样本，其次是床尘和沉降灰尘样本。实际意义 尽管不同样本类型反映室内环境内毒素暴露水平的有效性尚不清楚，但内毒素已被广泛测量。本研究表明，床尘样本的可重复性最佳，但它们不能反映由于农业等环境因素导致的暴露差异。可重复性中等的地板尘样本可能是大型现场研究中内毒素采样的最佳选择。
