The environmental sustainability of pharmaceutical waste inertization: Insights from toxicity characteristic leaching...

Inertization is used to solidify and immobilize pharmaceutical waste (PW) and reduce its leachability and environmental toxicity. This research is aimed to inertize PW and evaluate its environmental sustainability using Toxicity Characteristics Leaching Procedure (TCLP). A cross-sectional study of inertization of 28 batches of solid, liquid, semi-solid and injectable PWs was conducted from September 2024 to December 2024. Inertization of de-packaged, de-containerized and de-closured powdered PW was done in proportions of waste, cement, lime and water as 65 %: 15 %: 15 %: 5 %. Leachate coming on addition of TCLP solution was collected and analyzed with ICP-OES to identify heavy metals. Detailed characterization of inertized material was performed with thermogravimetric analysis, derivative thermogravimetry, FTIR and UV-Visible spectroscopy analyses. The results of hazard quotients, risk quotients and metals detected were analyzed with SPSS version 29.0 using binary logistic regression analysis. A total of 15 metals was detected where iron (9.33-26.72 mg/L) and aluminium (4.39-16.03 mg/L) were in higher concentration. Aluminium had none to potential health hazards as its hazard quotient (HQ) was > 1 in some samples whereas other elements showed no hazard potential because of their HQ < 1. Aluminium had potential environmental risks (i.e., risk quotient or RQ >1), and chromium and zinc exhibited no risks (i.e., RQ <1) to possible risks (i.e., RQ ≥1). As thresholds of all metals except aluminium in few samples were within United States Environmental Protection Agency limits, inertization of PW seems environmentally sustainable. This approach is replicable to resource constraint settings lacking sophisticated incinerator.