Preliminary Study of the Toxicology of Paper Rolls for Enrichment in Laboratory Animals

Abstract

         This pilot study aimed to evaluate the safety and potential toxicity of repurposed household toilet paper cores for use as environmental enrichment materials in laboratory animals. The study was conducted on 8-week-old female Wistar rats, which were divided into two groups: a control group without paper cores (n = 3) and an experimental group provided with paper cores (n = 5), observed over a continuous 7-month period. Household-derived paper cores, measuring 7.5 × 8 centimeters, were physically screened and sterilized prior to introduction into the cages. The investigation included the analysis of heavy metal concentrations in the paper cores and animal serum, the monitoring of body weight changes, and the assessment of hematological parameters, clinical chemistry, and the histopathology of vital organs at the end of the experiment. Heavy metal analysis of the paper cores revealed low concentrations of chromium (3.54 mg/kg), cadmium (0.06 mg/kg), and lead (2.85 mg/kg), all of which were below the safety standards for food-contact paper packaging. In the experimental animals, serum heavy metal levels in both groups were below 0.003 mg/L. No statistically significant differences were observed in body weight gain, hematology, or clinical chemistry parameters (ALT, CREA), with the exception of blood urea nitrogen (BUN) levels, which significantly differed between the groups but remained within the normal reference range. Furthermore, histopathological examination revealed no lesions indicative of any abnormalities. These findings demonstrate that household toilet paper cores are safe for use, causing no systemic toxicity or pathological changes in vital organs.