Spatial Variations in Key Greenhouse Gas Emissions across Illegal Dumpsites in Ibadan, Nigeria

Illegal dumpsites are common in Nigerian cities and these wastes are one of the significant contributors of greenhouse gas emissions (GHGEs). The study was designed to characterize GHGEs from the wastes as obtained from selected illegal dumpsites in Ibadan Southwest, Nigeria. Three dumpsites were randomly selected from the high (Okefoko), medium (NTC Joyce B) and low (Iyaganku GRA) density areas. Two most critical GHGEs (carbon dioxide, CO and 2 methane, CH ) were estimated. Values of CO measured three times per 4 2 week at specific periods of the day for 12 weeks during the months of January to April, 2011in parts per million (ppm) using a Telaire 7001 connected to a HOBO U12 data logger (Onset Corp, Bourne, MA). The CO values obtained were compared with available USEPA guideline 2 limits (300 – 400 ppm). Short-term CO concentrations ranged from 2 212-580 ppm for Okefoko, 224-1157 ppm for NTC Joyce B and 240 548 ppm for Iyaganku GRA. Highest (1157 ppm) CO emission was 2 recorded at the medium density area between 8 and10 am. The highest o temperature (39.4 C) was also recorded in the medium density area in the morning. The percentage composition of CH in the total potential 4 gas emissions from the dumpsites in the high, medium and low density areas were 0.000158 Gg/yr., 0.000026 Gg/yr. and 0.000012 Gg/yr. respectively. Levels of CO near dumpsites were within guideline 2 limits, while CH exceeded guideline limits. Evacuation of waste from 4 illegal dumpsites to authorized locations for recovery of GHGEs and material recycling should be promoted in urban areas of LDCs.