Morphometric Changes in the Lung Parenchyma of Wistar Rats Exposed to Biomass Cooking Smoke: A Domestic Air Pollution Model for Rural Nigeria

Biomass fuel combustion for domestic cooking remains prevalent in rural Nigerian communities, particularly in the North East and North West zones, where women and young children are chronically exposed to high levels of indoor smoke. This exposure is associated with chronic obstructive pulmonary disease, pulmonary hypertension, and lung cancer, yet experimental anatomical data characterising lung parenchymal changes in animal models representative of this exposure pattern are limited in the Nigerian literature. This study aims to evaluate morphometric changes in the lung parenchyma of Wistar rats subjected to controlled biomass cooking smoke exposure for 12 weeks. Rats will be exposed to wood and crop residue smoke in a whole-body inhalation chamber at concentrations measured to reflect domestic indoor air pollution levels in rural Nigeria. Lung sections will be stained with haematoxylin and eosin and Masson's trichrome for morphometric analysis of alveolar wall thickness, alveolar surface density, and peribronchiolar fibrosis. Bronchoalveolar lavage cytology will complement histological assessment. Findings are expected to provide histomorphometric evidence of progressive lung damage attributable to biomass smoke, supporting policy advocacy for improved domestic cooking environments in rural communities.

Keywords: biomass smoke, lung morphometry, pulmonary fibrosis, domestic air pollution, Wistar rats