Distribution of Particulate Matter in Cawthorne Channels Air Basin in Nigeria

Abstract

The concentrations of Particulate Matter (PM) were determined in tropical wetlands air basin of Cawthorne Channel, Awoba and Krakrama. The sampling was performed with well calibrated equipment (A MultiRAE PLUS (PGM – 50), a programmable Multi Gas monitor with an electrochemical sensor). Parameters measured were particulate matter with 1 µm, 2.5 µm (PM 2.5 ), 7 µm (PM 7 ) , 10 µm (PM 10 ) and Total suspended particulate (TSP). Seasonal variations were displayed by all fractions of particulate matter. TSP at Cawthorne Channels was observed, with very high concentration in January (346.1 µg/m 3 ) at the upwind and (401.7 µg/m 3 ) downwind in dry season. This was followed by wet season measurement. The PM 10 results at Cawthorne Channels also showed strong seasonal variations with very high concentration in January (313.6 µg/m 3 ) at the upwind and (367.5µg/m 3 ) downwind. Of all the respirable particulate size fractions studied, allowable International Standard according to USEPA (1990), was exceeded in PM 10 and PM 7 . PM 2.5 had values that were generally below 60.0 µg/m 3 while PM 1 had values below 10.0 µg/m 3 . The TSP levels exceeded 250.0 ug/m 3 , being Nigerian National allowable limit. The respirable particulate matter had no statistical difference between the upwind and downwind directions (p< 1) 0.05 .