Determination of the Oral Median Lethal Dose (LD₅₀) of Lead Acetate Trihydrate in Wistar Rats Using Probit Analysis

*Ewa Effiong Ewa and Okafor Azubuike Ikechukwu

Department of Medical Biochemistry, University of Cross River State, Calabar, Nigeria

*Corresponding author: ewaeffiongewa1@gmail.com; +2348138102907

ABSTRACT

Lead compounds remain significant environmental and occupational toxicants, necessitating accurate characterization of their acute toxicity profiles. This study aimed to determine the median lethal dose (LD₅₀) of lead acetate trihydrate in Wistar rats using probit analysis. Acute toxicity was evaluated by administering graded doses of lead acetate trihydrate (0–40 mg/kg) to experimental groups of rats, and mortality was recorded after 24 hours. Percentage mortality at each dose level was converted to probit units and plotted against log₁₀-transformed doses to establish a dose–response relationship. Linear regression analysis was performed to derive the LD₅₀ and its 95% confidence interval. A clear dose-dependent increase in mortality was observed across treatment groups. Regression analysis yielded the equation y = 10.081x – 9.4686 with a high coefficient of determination (R² = 0.986), indicating an excellent fit of the model. The LD₅₀ of lead acetate trihydrate was estimated to be 27.2 mg/kg body weight, corresponding to approximately 14.9 mg/kg of elemental lead (Pb), with a 95% confidence interval of 24.9–29.8 mg/kg (13.6–16.3 mg/kg Pb), demonstrating good precision. These findings confirm that lead acetate trihydrate exhibits significant acute toxicity in Wistar rats. The relatively low LD₅₀ value underscores the potential health risks associated with acute exposure to lead compounds. This study provides reliable toxicological data that may contribute to risk assessment and the development of safety guidelines for lead exposure.

Keywords: Lead acetate; Acute toxicity; LD₅₀; Probit analysis; Dose-response; Wistar rats

CITE AS: Ewa Effiong Ewa and Okafor Azubuike Ikechukwu (2026). Determination of the Oral Median Lethal Dose (LD₅₀) of Lead Acetate Trihydrate in Wistar Rats Using Probit Analysis. IDOSR JOURNAL OF BIOCHEMISTRY, BIOTECHNOLOGY AND ALLIED FIELDS 11(2):10-14.  https://doi.org/10.59298/IDOSR/JBBAF/2026/1121014