Work

Does human excreta fertilization increase pathogen contamination in sandy soils?

Year: 2025

Type: article

Abstract: • First study on soil fecal indicators after human excreta fertilization. • No E. coli or Salmonella detected in soil after applying hygienized fecal compost. • Clostridium perfringens levels unchanged after fecal compost use in sandy soils. • Clostridium perfringens has a high temporal and spatial variability in soil. The use of human excreta in the context of the circular economy has the potential to recycle nutrients, save water and energy, and sequester carbon. However, the risk of pathogen contamination of soil and crops, particularly from land application of solid human excreta (feces), is a realistic scenario. In our study we investigated a double thermophilically treated and quality assured compost (Hygienized Human Feces Compost). We used indicator organisms for fecal contamination to monitor the risk of pathogen contamination of the soil after application of human feces compost. Indicator organisms were Escherichia coli , Salmonella spp., Enterococcus spp. and Clostridium perfringens . One pot experiment under semi-controlled conditions and three on-farm experiments were conducted on loamy sand and sand soils. The experimental period ranged from 58 to 1123 days. The levels of fecal indicator organisms in soil show a consistent pattern across all experiments. E. coli , Salmonella spp. and Enterococcus spp. were not detected in any of the soil samples. C. perfringens was found in concentrations ranging from <10 to 10 3 CFU g −1 FM. However, there was no evidence of a systematic increase in the soil concentrations of C. perfringens following human feces compost application. In different years and under different experimental conditions, we were not able to detect any increase in the concentration of indicator organisms for fecal contamination in our experiments. We therefore assume that sandy soils might be generally suitable for application of quality-assured fertilizers from human excreta.

Source: Waste Management

DOI: 10.1016/j.wasman.2025.115314

Authors: Jan-Ole Boness, Timo Kautz, Bärbel Kroschewski, Roland Hoffmann-Bahnsen

Institutions: Humboldt-Universität zu Berlin, Eberswalde University for Sustainable Development

Language: English

Topic: Fecal contamination and water quality

Subfield: Water Science and Technology

Field: Environmental Science

Domain: Physical Sciences

SDGs: Life on land, Responsible consumption and production, Good health and well-being

Open Access status: hybrid

Estimated APC paid: $4,450