Multisystem Toxicological Effects of Petroleum Hydrocarbon Exposure in Chickens: A Sex- And Duration-Dependent Analysis

Abstract

Petroleum hydrocarbon contamination remains a persistent environmental challenge in regions with sustained oil exploration and production, where chronic exposure frequently occurs alongside heavy metal co-pollution. Unlike acute toxicity, long-term environmental exposure may induce progressive and interconnected disturbances across multiple physiological systems. This study evaluated the multisystem toxicological effects of chronic petroleum hydrocarbon exposure in chickens using an integrated analytical framework. Chickens exposed to a petroleum hydrocarbon-contaminated environment for 6 and 12 months were compared with unexposed controls, with analyses stratified by sex and exposure duration. Endocrine, hepatic, renal, cardiovascular, hematological, oxidative stress, inflammatory, and heavy metal parameters were jointly assessed to characterize systemic toxicity. Chronic exposure was associated with coordinated disturbances across all evaluated systems, including endocrine dysregulation, hepatorenal impairment, cardiovascular injury, hematological abnormalities, antioxidant depletion, lipid peroxidation, inflammatory activation, and accumulation of chromium, lead, and zinc. Oxidative stress and inflammation emerged as central mechanisms linking multisystem dysfunction, while heavy metal burden further amplified toxicological effects. Sex-dependent differences were evident, with females exhibiting greater endocrine, oxidative, and inflammatory disturbances and males showing more pronounced cardiovascular injury and metal accumulation. Toxicological severity increased with exposure duration, indicating cumulative effects of prolonged environmental contamination. This integrated multisystem evaluation demonstrates that petroleum hydrocarbons induce systemic toxicity through interacting biological pathways rather than isolated organ-specific mechanisms. The findings highlight chickens as sensitive sentinel species and underscore the ecological, food safety, and public health implications of chronic petroleum hydrocarbon contamination.