Assessment of Chronic Inhalation Exposure Effects of Dichlorvos (Dichlorvos) on Cardioprotective and Atherogenic Indices in the Blood of New Zealand White Rabbits

Background: Dichlorvos, a widely used organophosphate pesticide, is frequently applied in agricultural and domestic settings. Its high volatility makes inhalation a common route of exposure, raising concerns about its chronic effects on cardiovascular health. Lipid profile–derived indices are reliable predictors of cardiovascular risk and can provide insights into pesticide-induced cardiotoxicity. Aim: This study evaluated the chronic effects of dichlorvos administered orally and by inhalation on cardioprotective and atherogenic indices in New Zealand White rabbits. Methodology: Thirty six male rabbits (1.0–1.2 kg) were divided into nine groups (n = 4 each): oral exposure, inhalation exposure, and controls for 30, 60, and 90 days. Rabbits received 10% of the LD₅₀ dose of dichlorvos (0.05 mg/m³) daily, either orally or via inhalation chambers (4 h/day). Serum lipid profiles were analyzed, and indices including Castelli’s risk indices (CRI-I, CRI-II), triglyceride/HDL-C ratio (TG/HDL-C), atherogenic coefficient (AC), atherogenic index of plasma (AIP), and anti-atherogenic index (AAI) were calculated. Data were analyzed using ANOVA with Tukey’s post-hoc test (p < 0.05). Results: At 30 days, only AAI showed significant reduction in exposed groups compared with controls (p < 0.05). By 60 and 90 days, CRI-I, CRI-II, TG/HDL-C, AC, and AIP were significantly elevated, while AAI declined progressively. Inhalation exposure produced higher elevations in atherogenic indices, whereas oral exposure caused greater reductions in AAI. Conclusion: Chronic dichlorvos exposure disrupts lipid homeostasis in a time-dependent manner, reducing cardioprotection and increasing atherogenic risk. Inhalation exposure appears more hazardous than oral administration, underscoring the need for stricter regulation and public health awareness.