Paraquat dichloride is a toxic bipyridine herbicide widely used for weed control in fruit orchards and forestry. Its fumes primarily affect the lungs due to preferential accumulation in lung alveolar cells. Aim: This study investigates paraquat toxicity in pregnant Wistar rats at varying doses over a three-week gestational period. Methods: A total of seventy-two Wistar rats were used, with 48 females entering the experimental phase after mating with males. The female rats were randomly divided into four groups: Group 1 (Normal female, n=12), Group 2 (1 mg/ml/kg bw of paraquat dichloride, n=12), Group 3 (2.5 mg/ml/kg bw, n=12), and Group 4 (5 mg/ml/kg bw, n=12). Tissues were examined weekly and prepared for histological analysis using a Primo Star ZEISS light microscope. Results: At the end of the third week, lung tissue sections exhibited varying degrees of injury, including mild inflammation, taller and slender respiratory epithelium indicating stress, bronchiolar dilation, and fibrotic changes in lung stroma. Notably, the lungs of the foetuses showed no significant histological differences compared to controls. Conclusion: Maternal exposure to paraquat during pregnancy results in dose-dependent lung inflammation and fibrosis. Recommendations for new policies to prevent perinatal maternal exposure to paraquat are warranted.
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