Environmental and anthropogenic factors associated with the likelihood of detecting Salmonella in agricultural watersheds

Magaly Toro, Daniel Weller, Romina Ramos, Leonela Diaz, Francisca P. Alvarez, Angelica Reyes-Jara, Andrea I. Moreno-Switt, Jianghong Meng, Aiko D. Adell

Research output: Contribution to journalArticlepeer-review

11 Citations (Scopus)

Abstract

Surface water is one of the primary sources of irrigation water for produce production; therefore, its contamination by foodborne pathogens, such as Salmonella, may substantially impact public health. In this study, we determined the presence of Salmonella in surface water and characterized the relationship between Salmonella detection and environmental and anthropogenic factors. From April 2019 to February 2020, 120 samples from 30 sites were collected monthly in four watersheds located in two different central Chile agricultural regions (N = 1080). Water samples from rivers, canals, streams, and ponds linked to each watershed were obtained. Surface water (10 L) was filtrated in situ, and samples were analyzed for the presence of Salmonella. Salmonella was detected every month in all watersheds, with a mean detection percentage of 28% (0%–90%) across sampling sites, regardless of the season. Overall, similar detection percentages were observed for both regions: 29.1% for Metropolitan and 27.0% for Maule. Salmonella was most often detected in summer (39.8% of all summer samples tested positive) and least often in winter (14.4% of winter samples). Random forest analysis showed that season, water source, and month, followed by latitude and river, were the most influential factors associated with Salmonella detection. The influences of water pH and temperature (categorized as environmental factors) and factors associated with human activity (categorized as anthropogenic factors) registered at the sampling site were weakly or not associated with Salmonella detection. In conclusion, Salmonella was detected in surface water potentially used for irrigation, and its presence was linked to season and water source factors. Interventions are necessary to prevent contamination of produce, such as water treatment before irrigation.

Original languageEnglish
Article number119298
JournalEnvironmental Pollution
Volume306
DOIs
Publication statusPublished - 1 Aug 2022

Keywords

  • Food safety
  • Microbiological contamination
  • Random forest
  • Salmonella
  • Surface water
  • Water quality
  • Waterborne pathogens

ASJC Scopus subject areas

  • Toxicology
  • Pollution
  • Health, Toxicology and Mutagenesis

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