Expanded Polystyrene Exposure and Nitrite-Related Absorbance in Eisenia fetida
Abstract
Microplastic contamination can affect soil properties, microbial communities, and nutrient cycling. This study evaluated whether expanded polystyrene (EPS) microplastic exposure during vermicomposting affected nitrite-related absorbance in vermicast produced by Eisenia fetida. Fifty independent experimental units were divided into a control treatment without EPS (n = 25) and an EPS treatment (n = 25). After a 12-day exposure period, vermicast samples were extracted with calcium chloride and analyzed using a modified Griess-type colorimetric reaction. Griess-reactive absorbance was measured at 540.1 nm with a visible-light spectrophotometer. Mean absorbance was 1.25 absorbance units (AU) in the EPS treatment and 0.766 AU in the control, a 63% difference between group means. A Mann-Whitney U test indicated a significant difference between treatments (U = 75, z = -4.6, p < 0.01). Under these experimental conditions, EPS exposure was associated with greater Griess-reactive absorbance in vermicast. Because no nitrite calibration curve was generated, the results cannot be interpreted as absolute nitrite concentrations, and the mechanism underlying the observed difference remains unresolved.
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BibTeX
@misc{guilfoyle2026expanded,
title = {{Expanded Polystyrene Exposure and Nitrite-Related Absorbance in Eisenia fetida}},
author = {Lucy Grey Guilfoyle and Jillian Paglinawan and Xiaojing Hu},
howpublished = {EcoEvoRxiv},
year = {2026},
month = oct,
doi = {10.32942/x2r09v},
url = {https://ecoevorxiv.org/repository/view/15324/},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Expanded Polystyrene Exposure and Nitrite-Related Absorbance in Eisenia fetida
AU - Lucy Grey Guilfoyle
AU - Jillian Paglinawan
AU - Xiaojing Hu
PY - 2026
DA - 2026/10/02
PB - EcoEvoRxiv
DO - 10.32942/x2r09v
UR - https://ecoevorxiv.org/repository/view/15324/
AB - Microplastic contamination can affect soil properties, microbial communities, and nutrient cycling. This study evaluated whether expanded polystyrene (EPS) microplastic exposure during vermicomposting affected nitrite-related absorbance in vermicast produced by Eisenia fetida. Fifty independent experimental units were divided into a control treatment without EPS (n = 25) and an EPS treatment (n = 25). After a 12-day exposure period, vermicast samples were extracted with calcium chloride and analyzed using a modified Griess-type colorimetric reaction. Griess-reactive absorbance was measured at 540.1 nm with a visible-light spectrophotometer. Mean absorbance was 1.25 absorbance units (AU) in the EPS treatment and 0.766 AU in the control, a 63% difference between group means. A Mann-Whitney U test indicated a significant difference between treatments (U = 75, z = -4.6, p < 0.01). Under these experimental conditions, EPS exposure was associated with greater Griess-reactive absorbance in vermicast. Because no nitrite calibration curve was generated, the results cannot be interpreted as absolute nitrite concentrations, and the mechanism underlying the observed difference remains unresolved.
ER -