Correlation and Regression Analyses of Particulate Matter Concentrations and Microbial Loads in Air at Some Secondary Schools in Port Harcourt, Rivers State, Nigeria

This study assessed the relationship between particulate matter (PM₁, PM₂.₅, PM₄, PM₇, and PM₁₀) and airborne microbial load (bacteria and fungi) in school environments within Port Harcourt, Nigeria. Particulate concentrations were measured using aeroset handheld particle counter 531S, while microbial loads were determined with passive settle plate method using 9 cm diameter petri dishes and expressed as CFU/m³. Correlation and regression analyses were applied to evaluate associations under dry and wet conditions. Results showed moderate positive correlations between bacterial load and fine particles, particularly PM1 (r = 0.5287), PM2.5 (r = 0.4430), PM7 (r = 0.4238) in the wet season. Fungal load exhibited stronger associations with coarse particles PM₄ (r = 0.6487) and PM₇ (r = 0.7007), especially during the dry season. Regression analysis indicated weak and non-significant relationships between bacteria and PM (R2 = 0.088 and 0.104 for PM1 and PM2.5 respectively; R2 = 0.01, 0.006, 0.015 for PM4, PM7, PM10 respectively) while fungi showed moderate relationships with PM₇ being statistically significant (p < 0.05) and R2 = 0.427 and 0.456 for PM4 and PM7 respectively. The study demonstrates that coarse particulate matter plays a more significant role in fungal distribution than bacterial transport and highlights the importance of considering both biological and non-biological pollutants in school air quality assessments.