Air Quality at Artisanal Crude Oil Refinery Sites in Igia-Ama, Tombia Kingdom, Rivers State, Nigeria

Abstract

Artisanal crude oil refining is an illegal operation thriving in the oil-rich Niger Delta region of Nigeria, and their activities are known to cause serious air pollution, evident by incidences of black soot pollution in many parts of this region. This study aimed to ascertain the air quality around artisanal crude oil refinery sites situated in Igia-Ama, Tombia Kingdom, Rivers State, Nigeria. Air quality assessment was carried out using air quality sensor for physicochemical parameters and settle plate exposure for microbial parameters, monitored for both dry and wet seasons. During the wet season, SOx, NOx, VOC, CH4, CO, CO2,O3, NH3, H2S, PM 1, PM 2.5, PM 7, PM10, TSP, Noise, Wind speed, Air temperature, Relative humidity concentration ranged from 0-0.05 ppm, 0.04 - 0.07 ppm, 1004.00 - 1320.00 ppm, 34.33 - 39.67 ppm, 1.33 - 3.00 ppm, 765.00-1556.67 ppm, 0.2 to 0.3 ppm, 0.05 to 0.10 ppm, 0.13 to 0.20 ppm, 15.73 - 0 21.50 µg/m3, 33.53-34.17 µg/m3, 55.47 - 55.93 µg/m3, 64.30 - 67.50 µg/m3, 49.60 - 76.97 µg/m3, 45.63– 48.37dB, 1.13 -1.23 M/S, 28.30 - 29.73oC and 63.13 - 69.23 % respectively. During the dry season, SOx, NOx, VOC, CH4, CO, CO2, O3, NH3, H2S, PM 1, PM 2.5, PM 7, PM10, TSP, Noise, Wind speed, Air temperature, Relative humidity concentration ranged from 0.08-0.53 ppm, 0.12 - 0.19 ppm, 1027.33 - 1750.33 ppm, 21.00 - 50.33 ppm, 1.33 – 2.67 ppm, 1226.67-1551540.00 ppm, 0.09 to 0.55 ppm, 0.04 to 0.09 ppm, 0.04 to 0.63 ppm, 26.47 - 33.97 µg/m3, 39.60-51.23 µg/m3, 57.90 - 84.27 µg/m3, 89.13 - 100.17 µg/m3, 128.83 – 170.30 µg/m3, 49.17– 56.73dB, 0.15 -1.97 M/S, 29.07 - 32.57oC and 66.67 - 71.87 % respectively. Results revealed statically significant differences (p<0.05) in air parameters per season (dry and wet) and between impacted sites and control, as regards NOx, VOC, CO2, O3, PM 1, PM 2.5, PM 4, PM 7, PM 10, TSP and noise levels. During the dry season, Total Heterotrophic Bacterial Count (THBC) ranged from 4.4-4.8 log CFU/m3, and Total Fungal Count (TFC) from 4.4-4.8 log CFU/m3. During the wet season THBC ranged from 4.9-5.2 log CFU/m3 and TFC ranged from 2.5-4.6 log CFU/m3. Results revealed no statically significant differences (p<0.05) in microbial count per season (dry and wet) as well as between the polluted sites and control. The bacterial isolates were identified as belonging to five genera: Bacillus, Micrococcus, Pseudomonas, Staphylococcus and Escherichia, while the fungal isolates belong to three genera: Fusarium, Aspergillus and Penicillium. The excessive concentrations of NOx, SOx, and the presence of allergenic and pathogenic microorganisms could pose danger to public health.