Search

Fecal pollution remains a challenge for water quality managers at Great Lakes and inland recreational beaches. The fecal indicator of choice at these beaches is typically Escherichia coli (E. coli), determined by culture-based methods that require over 18 h to obtain results. Researchers at the United States Environmental Protection Agency (EPA) have developed a rapid E. coli qPCR methodology (EPA Draft Method C) that can provide same-day results for improving public health protection with demonstrated sensitivity, specificity, and data acceptance criteria. However, limited information is currently available to compare the occurrence of E. coli determined by cultivation and by EPA Draft Method C (Method C). This study provides a large-scale data collection effort to compare the occurrence of E. coli determined by these alternative methods at more than 100 Michigan recreational beach and other sites using the complete set of quantitative data pairings and selected subsets of the data and sites meeting various eligibility requirements. Simple linear regression analyses of composite (pooled) data indicated a correlation between results of the E. coli monitoring approaches for each of the multi-site datasets as evidenced by Pearson R-squared values ranging from 0.452 to 0.641. Theoretical Method C threshold values, expressed as mean log10 target gene copies per reaction, that corresponded to an established E. coli culture method water quality standard of 300 MPN or CFU /100 mL varied only from 1.817 to 1.908 for the different datasets using this model. Different modeling and derivation approaches that incorporated within and between-site variability in the estimates also gave Method C threshold values in this range but only when relatively well-correlated datasets were used to minimize the error. A hypothetical exercise to evaluate the frequency of water impairments based on theoretical qPCR thresholds corresponding to the E. coli water quality standard for culture methods suggested that the methods may provide the same beach notification outcomes over 90% of the time with Method C results differing from culture method results that indicated acceptable and unacceptable water quality at overall rates of 1.9% and 6.6%, respectively. Results from this study provide useful information about the relationships between E. coli determined by culture and qPCR methods across many diverse freshwater sites and should facilitate efforts to implement qPCR-based E. coli detection for rapid recreational water quality monitoring on a large scale in the State of Michigan. • A rapid E. coli qPCR method can provide same-day results for beach monitoring. • A large study compared the occurrence of E. coli by qPCR and culture in Michigan. • Results provide an indication of the degree of correlation between the methods. • Options for a beach notification threshold value for the PCR method are presented. [ABSTRACT FROM AUTHOR]

Sieved vacuum bag dust from the homes of 143 children in Detroit was analyzed by mold specific quantitative PCR (MSQPCR) and the Environmental Relative Moldiness Index (ERMIsm) was calculated for each home. Children living in these homes were grouped as non-asthmatic (n =83), moderately asthmatic (n =28) and severely asthmatic (n =32) based on prescription medication usage for their asthma management (none, occasional and daily, respectively). The mean ERMI for each group of homes was 6.2 for non-asthmatic, 6.3 for moderately asthmatic and 8.2 for severely asthmatic children. The ERMI values in the homes of severely asthmatic children were significantly greater compared to the non-asthmatics (p =0.04 in Wilcoxon Rank-sum test). Aspergillus niger and Aspergillus unguis were the primary mold species that distinguished severely asthmatic children''s homes and non-asthmatic children''s homes (p <0.05; Wilcoxon Rank-sum test). The determination of the home''s ERMI values may aid in prioritizing home remediation efforts, particularly in those children who are at increased risk for asthma exacerbation. [Copyright &y& Elsevier]