Source, geochemical spreading and risks of trace metals in particulate matter 2.5 within a gas flaring area in Bayelsa State, Nigeria

Abstract

The study investigated the source, geochemical spreading and risks assessment of trace metals in particulate matter 2.5 (PM2.5) within a gas flaring area in Bayelsa State, Nigeria. PM2.5 was measured using Geintek Particulate matter sampler APM131 monitor. Seven locations within 3000 m of the gas flaring area were sampled, with a control location established at about 7000 m from flare stark. The trace metals trapped in the PM2.5 were analyzed using flame atomic absorption spectrometry. The mean level of trace metals ranged from 2.75 – 7.56 µg/m3, 0.03 – 2.82 µg/m3, 0.16 – 1.11 µg/m3, 0.32 – 1.02 µg/m3, 1.32 – 3.34 µg/m3, and 0.15 – 2.07 µg/m3 for iron, manganese, nickel, lead, zinc and vanadium, respectively. There was statistical dissimilarity (P 0.05) for manganese, vanadium and lead. Pollution indices and index of geoaccumulation showed low to moderate contamination. The overall risk index reveals a low hazard. The enrichment factor and principal components analysis showed the metals are from anthropogenic and natural sources. Zinc correlates strongly with iron, manganese and nickel, an indication that these metals are from similar sources. The carcinogenic and non - carcinogenic hazards were within the threshold limits of 10-6 to 10-4 and <1, respectively. Based on the result, there are no hazardous health effects resulting from the inhalation of trace metals in PM2.5 for the age bracket being studied. However, there is a need to constantly monitor the level of these metals in the air via routine emission monitoring to forestall possible health risks.

Keywords

• air quality
• source of air heavy metals
• metal enrichment
• ecological risk
• environmental health