Abstract
Drilling fluids (drilling muds) are indispensable in oil and gas exploration, serving critical functions such as borehole stabilization, lubrication, and cuttings transport. However, these fluids are complex chemical mixtures containing heavy metals, petroleum hydrocarbons, salts, and various functional additives that may pose significant toxicological risks to biological systems and the environment. This mini-review summarizes current evidence on the toxicity effects of drilling fluids, with particular emphasis on toxic components, mechanistic pathways, mammalian toxicity, and ecological impacts. Both water-based and oil-based drilling fluids have been shown to induce adverse effects, including oxidative stress, enzyme inhibition, tissue irritation, and genotoxicity. Experimental studies, especially those conducted by Mamyrbayev et al ., provide compelling evidence of acute and subacute systemic toxicity in mammalian models following oral and dermal exposure, manifested by organ damage, biochemical alterations, and histopathological changes. Ecotoxicological investigations further demonstrate harmful effects on algae, aquatic invertebrates, fish, and benthic communities, as well as risks associated with soil and groundwater contamination from improper waste disposal. Advances in environmentally safer drilling fluid formulations, improved waste management, remediation technologies, and regulatory oversight have contributed to risk reduction; however, important knowledge gaps remain. In particular, the chronic effects of low-dose exposure, combined toxicity of multicomponent formulations, and long-term ecosystem recovery require further investigation. A comprehensive understanding of drilling fluid toxicity is essential for balancing operational efficiency with environmental protection and occupational health.