Toxicological Impact of Petroleum Vapours on Liver and Kidney Function: A Comprehensive Review

Abstract

Petroleum-derived volatile organic compounds (VOCs), particularly benzene, toluene, ethylbenzene, and xylene (BTEX), are among the most harmful chemical pollutants affecting human health. Chronic exposure to these substances, whether in the workplace or through contaminated environments, has been linked to serious toxicological effects, especially on vital organs such as the liver and kidneys. This review compiles and evaluates research findings published from 2005 to 2025, integrating evidence from human epidemiological studies, controlled animal experiments, and mechanistic investigations. The analysis identifies several core pathways through which petroleum vapours cause damage, including oxidative stress, the metabolic bioactivation of reactive intermediates, mitochondrial impairment, and the activation of inflammatory signalling cascades. The liver, which is the body’s central site for hydrocarbon metabolism through cytochrome P450 enzyme systems, shows clear signs of injury in exposed individuals. This injury is often reflected in abnormal laboratory findings such as elevated alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT), and bilirubin levels. The kidneys, responsible for filtering blood and excreting hydrocarbon metabolites, are also highly vulnerable. Reported nephrotoxic effects include damage to both glomerular and tubular structures, protein loss in urine (proteinuria), and a reduction in the glomerular filtration rate (GFR). These toxic outcomes are particularly evident among high-risk groups, including petroleum refinery workers, fuel station attendants, and urban residents living in oil-producing areas such as Nigeria’s Niger Delta. Biochemical markers like malondialdehyde (MDA), reduced glutathione (GSH), and nitric oxide (NO) had implicated oxidative stress as a major contributor to organ injury. Weak enforcement of safety regulations, low usage of personal protective equipment (PPE), and poor environmental management in many low and middle-income countries continue to heighten exposure risks. This review underscores the urgent need for comprehensive biomonitoring programs, stronger regulatory frameworks, and expanded research to address long-term health effects, including possible epigenetic changes, arising from petroleum vapour exposure.