Impact of PM2.5 on common fruit species around Ghorahi Cement Factory, Dang, Nepal

Air pollution is a significant environmental concern in industrial and urban regions, posing risks to ecosystems and vegetation health. Semi-urban industrial areas such as Dang, Nepal, remain understudied despite substantial emissions from cement industries, highlighting the need to assess plant responses and their role as bio-indicators. This study evaluated the impacts of PM₂.₅ on common fruit plant species surrounding the Ghorahi Cement Factory (GCF). Eight sampling sites were selected using a wind rose diagram to represent upwind and downwind sites during dry and wet seasons. Leaf samples were analyzed for Air Pollution Tolerance Index (APTI), Specific Leaf Area (SLA), and Dust Accumulation (DA), while PM₂.₅ concentrations were monitored across a spatial gradient around the GCF in each season. PM₂.₅ concentrations were higher during the dry season and decreased during the wet season due to meteorological and anthropogenic influences. Plant responses showed clear seasonal variation, with species exhibiting higher tolerance during the wet season. PM₂.₅ showed a positive association with dust accumulation and a negative relationship with key physiological parameters, indicating pollution-induced stress, particularly during the dry season. SLA varied among species, reflecting differences in adaptive capacity, while DA highlighted species-specific dust retention potential. The observed physiological responses suggest that prolonged exposure to PM₂.₅ may influence the health of fruit plant species in industrial environments, with potential implications for vegetation management, agricultural sustainability, and environmental monitoring. Based on the average APTI values, Citrus limon , Psidium guajava , and Mangifera indica were classified as tolerant species and are suitable for greenbelt development, while Artocarpus heterophyllus , Morus alba , and Litchi chinensis were categorized as intermediate, indicating overall species-specific variability in pollution response across seasons. This study provides insights into plant-based monitoring of PM₂.₅ in semi-urban industrial environments of Nepal and represents the first systematic evaluation of seasonal variation in APTI, SLA, and DA in common fruit plant species near an industrial source.