Assessing Health and Environmental Effects of Air Particulate Matter in Port Harcourt Metropolis, Rivers State, Nigeria

Background: Airborne particulate matter poses significant environmental and public health risks in rapidly urbanising industrial centres such as Port Harcourt, Nigeria, where residents experience frequent exposure to ambient black soot. This study assessed ambient particulate concentrations, seasonal variations, self-reported soot exposure, and associated respiratory morbidity among residents.Methods: A descriptive cross-sectional survey of 381 residents was conducted alongside real-time particulate matter monitoring across six strategic locations in the Port Harcourt metropolis over a 12-month period. Data on sociodemographic characteristics, perceived exposure, and respiratory symptoms were collected using structured questionnaires. Particulate concentrations ({PM}1.0, {PM}2.5, {PM}₁₀, and total suspended particulates) were recorded across wet and dry seasons. Statistical analyses included descriptive summaries, paired seasonal comparisons (paired t-tests), and multivariable logistic regression to evaluate factors associated with respiratory morbidity.Results: Ambient particulate readings across monitoring sites ranged from 7 to 37 µg/m³ for {PM}2.5 and 48 to 153 µg/m³ for {PM}₁₀. Concentrations were significantly elevated during the dry season compared to the wet season, with mean dry–wet differences of 3.0 µg/m³ for {PM}1.0 (p=0.041), 6.0 µg/m³ for {PM}2.5 (p=0.044), and 46.7 µg/m³ for {PM}₁₀ (p=0.003). Among the 381 respondents, 191 (50.1%) reported daily exposure to outdoor black soot, and 184 (48.3%) reported experiencing respiratory symptoms. Multivariable regression analyses indicated that daily black soot exposure (adjusted odds ratio [AOR] = 4.12; 95% CI: 2.01–8.44) and residential proximity to major soot sources (AOR = 2.45; 95% CI: 1.42–4.23) were significantly associated with increased odds of respiratory morbidity.Conclusion: Ambient particulate concentrations in Port Harcourt exhibit notable spatial and seasonal variability, peaking during the dry season. High levels of perceived soot exposure and respiratory symptoms underscore the substantial public health impact of local air pollution. Targeted environmental regulations, continuous air quality monitoring, and enhanced respiratory health interventions are urgently required.