Histopathological evaluation of Wistar rats exposed to particulate matter polluted ambient air of port Harcourt metropolis, rivers state, Nigeria

ABSTRACT Background: Globally, air pollution constitutes a significant threat to human health affecting various organs of the body. Objective: This study evaluated the histopathological changes in respiratory, renal, and cardiac tissues of the Wistar rats exposed to particulate matter (PM) polluted ambient air (indoor and outdoor). Methods: Twenty Wistar rats were imported from the University of Nigeria, Nsukka (non-PM polluted environment). Four rats were immediately sacrificed before the commencement of the study to serve as a control group. The remaining 16 rats were grouped into two (indoor and outdoor) (n=8), then left for 90 days. At the end of the 90 days, the rats were euthanized using diethyl ether, then the lung, hearts, and kidneys were harvested for histopathological studies. Results: Indoor and outdoor PM exposure showed thickening of inter-alveolar septa and shrinking of alveoli sacs in the lungs. Fused peripherally placed nuclei, branched, weaved, and reunited cardiac myofibril were observed in the tissues from the indoor and outdoor exposed groups. Occlusion of bowman space was observed in the outdoor PM exposed group. Conclusions: PM exposure in River state was associated with marked distortion of the histo architecture of the lungs, heart, and kidney among the experimental animals.