Cho Sook Ja, Ramachandran Gurumurthy, Grengs Jason, Ryan Andrew D, Eberly Lynn E, Adgate John L
Division of Environmental Health Sciences, School of Public Health, University of Minnesota, Minneapolis, Minnesota, USA.
J Occup Environ Hyg. 2008 Feb;5(2):107-18. doi: 10.1080/15459620701827049.
To characterize seasonal variation of three allergens (dust mite, cat, and cockroach) and total culturable fungi and to explore whether residential characteristics were associated with the concentrations of these agents, floor dust was collected from 47 inner-city homes in Minneapolis, Minnesota, over a 1-year period. A longitudinal analysis of allergen and fungal concentrations was carried out using mixed-effect models. Overall, relative humidity was a better predictor of allergen concentrations over time than indoor temperature. Seasonal variation of cat and cockroach allergens was negligible compared with the variability associated with residential characteristics such as race/ethnicity, family income, and the presence of cats. Fungal concentrations showed significant seasonal variation that outweighed the variability associated with residential characteristics. Less than 30% of the dust mite allergen and cockroach allergens concentrations were above limits of detection. Observed cockroach allergen concentrations were higher in Spanish- and Somali-speaking households than in English-speaking households, while English-speaking households had significantly higher cat allergen concentrations compared with the other language groups. The ratios of within-home to between-home variance for total culturable fungi, dust mite, cockroach, and cat allergen concentrations were 2.54, 1.91, 0.55, and 0.24, respectively. This ratio is used to predict the number of repeated measurements of each allergen required to robustly estimate long-term exposure estimates such that exposure misclassification bias is kept within acceptable limits. It is not clear whether repeated measurements of dust mite and cockroach allergens are required for long-term average exposure because of the large fraction of nondetects. It is concluded that a single measurement of cat allergen is a reasonable surrogate for long-term average exposure, since repeated measurements over time were highly correlated. Total culturable fungi will require greater than nine repeated measurements for robust assessment of long-term exposures because of low correlations in fungal measures over time.
为了描述三种过敏原（尘螨、猫和蟑螂）以及可培养真菌总数的季节性变化，并探讨居住特征是否与这些物质的浓度相关，在一年时间里，从明尼苏达州明尼阿波利斯市47户市中心家庭中采集了地板灰尘。使用混合效应模型对过敏原和真菌浓度进行了纵向分析。总体而言，随着时间的推移，相对湿度比室内温度更能预测过敏原浓度。与种族/民族、家庭收入和猫的存在等居住特征相关的变异性相比，猫和蟑螂过敏原的季节性变化可以忽略不计。真菌浓度呈现出显著的季节性变化，其超过了与居住特征相关的变异性。尘螨过敏原和蟑螂过敏原浓度低于检测限的比例不到30%。观察到讲西班牙语和索马里语的家庭中蟑螂过敏原浓度高于讲英语的家庭，而讲英语的家庭中猫过敏原浓度显著高于其他语言群体。可培养真菌总数、尘螨、蟑螂和猫过敏原浓度的家庭内方差与家庭间方差之比分别为2.54、1.91、0.55和0.24。该比例用于预测每种过敏原为可靠估计长期暴露量所需的重复测量次数，以便将暴露错误分类偏差控制在可接受范围内。由于未检测到的比例较大，尚不清楚长期平均暴露是否需要对尘螨和蟑螂过敏原进行重复测量。结论是，由于随时间的重复测量高度相关，单次测量猫过敏原是长期平均暴露的合理替代指标。由于真菌测量随时间的相关性较低，可培养真菌总数需要超过九次重复测量才能可靠评估长期暴露情况。
