Measurement of Organic Micropollutants in Rainwater as Indicators of Air Pollution in Onitsha, Anambra State, Nigeria

摘要

Concentrations of persistent organic micro-pollutants were measured in rainwater collected in Onitsha city of Anambra State, Nigeria throughout the year 2012. Gas Chromatography-Mass Spectrometry (GC-MS) was used for analyzing Polycyclic Aromatic Hydrocarbons (PAHs) while Gas Chromatography with Micro Electron Capture Detector (GC/μECD) was used in the identification and quantification of Organochlorine Pesticides (OCPs) and Polychlorinated Biphenyls (PCBs). The chromatograms were evaluated by comparison with appropriate standards of known concentration. From the results, the mean concentrations of the PAHs in the rainwater samples range from 0.010mg/L to 0.510mg/L, the mean concentrations of OCPs in the rainwater samples range from 0.002mg/L to 0.040mg/L while the mean concentration of PCBs in the rainwater samples ranges from 0.007mg/L to 0.045mg/L. The concentration of these pollutants in the rainwater samples were above the maximum contaminant limit set by the United States Environmental Protection Agency (USEPA) for potable water and serves as markers of air pollution in Onitsha. The likelihood of exposure of residents to these toxic organic micropollutants through the breathing of air is plausible and requires urgent intervention to mitigate their adverse health effect.