Exposure to airborne particulate matter and undernutrition in young rats: An in-depth histopathological and biochemical study on lung and excretory organs.

Environmental stressors, such as air particulate matter (PM) and nutrient deficiencies, can significantly impact crucial organs involved in detoxifying xenobiotics, including lungs, liver, and kidneys, especially in vulnerable populations like children. This study investigated the effect of 4-week exposure to Residual Oil Fly Ash (ROFA) on these organs in young rats under growth-restricted nutrition (NGR). We assessed histological, histomorphometric and biochemical parameters. ROFA exposure induced histological changes and inflammation in all three organs when compared to control (C) animals. Specifically, in lungs ROFA caused a significant reduction in alveolar airspace (C: 55.8 ± 1.8% vs. ROFA: 38.7 ± 3.0%, p < 0.01) and alveolar number along with changes in alveolar size distribution, and disruption of the smooth muscle layer which may impaired respiratory function. In the liver, ROFA increased binucleated cells, macro and microvesicles and both AST and ALT serum biomarkers (AST: C = 77.7 ± 1.3 vs. ROFA = 81.6 ± 1.3, p < 0.05; ALT: C = 44.5 ± 0.9 vs. ROFA = 49.4 ± 1.3, p < 0.05). In the kidneys, a reduced Bowman's space (C: 2.15 ± 0.2 mm vs. ROFA: 1.74 ± 0.2 mm, p < 0.05) was observed, indicative of glomerular filtration failure. NGR alone reduced Bowman's space (C: 2.15 ± 0.2 mm vs. NGR: 1.06 ± 0.1 mm, p < 0.001). In lung and liver NGR showed higher levels of proinflammatory cytokine IL-6 (p < 0.01 and p < 0.001, respectively) when compared to C. In conclusion, both stressors negatively affected lung and excretory organs in young rats, with nutritional status further modulating the physiological response to ROFA. These findings highlight the compounded risks posed by environmental pollutants and poor nutrition in vulnerable populations.