Abstract

The Environmental Relative Moldiness Index (ERMI) is a scale created to compare mold contamination levels in U.S. homes. The ERMI was developed as a result of the Department of Housing and Urban Development’s (HUD) first American Healthy Homes Survey (AHHS I), which sampled 1,096 homes selected to be representative of the U.S. housing stock. In AHHS I, a dust sample from each home was analyzed using quantitative PCR assays (qPCR) for 36 common indoor molds: 26 Group 1 molds, which were associated with water damage in homes and 10 Group 2 molds, which primarily enter the home from the outside environment. In 2019, HUD completed AHHS II by sampling 695 homes. Because lead was banned from paint in 1978, a larger proportion of homes selected for AHHS II had been built before 1978 compared to AHHS I. The 36 ERMI molds were analyzed in AHHS II exactly as in AHHS I. For the 36-ERMI molds, the rates of detection, average concentrations, and geometric means were in significant concordance (p < 0.001) between AHHS I and II, indicating that the ERMI methodology was stable over time. However, the average ERMI value in AHHS II homes was greater than in AHHS I. The reason for the difference was investigated by examining the Group 1 and 2 mold populations. The average summed logs of Group 1 molds were significantly greater in homes built before 1978 than the average for homes built later. Conversely, the average summed logs of Group 2 mold populations were the same in homes built before 1978 and homes built later. Since the summed logs of Group 2 mold is subtracted from the summed logs of Group 1 molds in the ERMI calculation, the average ERMI value was higher in AHHS II homes than AHHS I. In conclusion, by using the ERMI metric, we were able to demonstrate that water damage and mold growth were more likely to occur as homes get older.

摘要

环境相对霉菌指数 (ERMI) 是一种用于比较美国家庭霉菌污染水平的量表。ERMI 是住房和城市发展部 (HUD) 第一次美国健康住宅调查 (AHHS I) 的结果，该调查抽取了 1,096 所被选为代表美国住房存量的住宅。在 AHHS I 中，使用定量 PCR 分析 (qPCR) 对来自每个家庭的灰尘样本进行了分析，以检测 36 种常见的室内霉菌：26 种第 1 组霉菌，与家庭中的水损坏有关；10 种第 2 组霉菌，主要从外部环境。2019 年，HUD 通过对 695 个家庭进行抽样完成了 AHHS II。由于铅在 1978 年被禁止用于油漆，与 AHHS I 相比，1978 年之前建造的 AHHS II 房屋比例更大。AHHS II 中对 36 种 ERMI 霉菌的分析与 AHHS I 中完全一样。对于 36-ERMI 霉菌，AHHS I 和 II 之间的检出率、平均浓度和几何平均值具有显着一致性（p < 0.001），表明随着时间的推移，ERMI 方法是稳定的。然而，AHHS II 家庭中的平均 ERMI 值大于 AHHS I。通过检查第 1 组和第 2 组霉菌种群来调查差异的原因。在 1978 年之前建造的房屋中，第 1 组模具的平均总对数明显高于后来建造的房屋的平均值。相反，在 1978 年之前建造的房屋和后来建造的房屋中，第 2 组霉菌种群的平均总对数相同。由于在 ERMI 计算中从第 1 组模具的总和中减去第 2 组模具的总对数，