Spatiotemporal Variability in Microbial Quality of Western US Agricultural Water Supplies: A Multistate Study
| Autor: | Melissa L. Partyka, Edward R. Atwill, Jennifer A. Chase, Ronald F. Bond |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
0301 basic medicine
Irrigation Veterinary medicine Environmental Engineering 030106 microbiology Water supply Management Monitoring Policy and Law California 03 medical and health sciences Feces Water Supply Water Quality Farm water Food microbiology Waste Management and Disposal Water Science and Technology Shiga-Toxigenic Escherichia coli business.industry Agriculture Food safety Pollution Coliform bacteria Fecal coliform Food Microbiology Environmental science Water quality business |
| Zdroj: | Journal of environmental quality. 47(5) |
| ISSN: | 0047-2425 |
| Popis: | In 2011, the US Congress passed the Food Safety Modernization Act, which tasks the US Food and Drug Administration to establish microbiological standards for agricultural water. However, little data are available for the microbiological quality of surface water irrigation supplies. During the 2015 irrigation season, we conducted a baseline study on the microbial water quality of large irrigation districts in California ( = 2) and Washington ( 4). Monthly samples ( 517) were analyzed for bacterial indicators (fecal coliforms, enterococci, and ) and pathogens ( spp., O157, and non-O157 Shiga toxin-producing [STEC]). Although there was a high degree of variability (μ ± SD = 59.13 ± 106.0), only 11% of samples (56/517) exceeded 126 colony-forming units (CFU) 100 mL, and only six samples exceeded 410 CFU 100 mL. Two volumes of water were collected for pathogen analysis (1 L and 10 L); prevalence of in 10-L samples (68149) was nearly double of that found in 1-L samples (132/517). We found STEC during ∼9% of sampling events (58/517); serotypes O26 and O45 were the most common at 31 and 26%, respectively. Pathogens were not associated with exceedance of the regulatory threshold, yet the odds of detecting increased approximately threefold (odds ration [O.R.] = 3.14, 0.0001) for every log increase in turbidity. Microbiological outcomes were highly district-specific, suggesting drivers of water quality vary across spatiotemporal scales. The true risk of contamination of produce from irrigation water supplies remains unknown, along with the optimal monitoring strategy to improve food safety. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Plný text