Facultad de Ciencias Quimicas, Universidad Autonoma de Baja California, Calzada Tecnologico S/N, Mesa de Otay CP 22390. Tijuana, Baja California, Mexico
Dumpsites can produce serious pollution problems in soil, water and air, and are the most frequent method of solid waste disposal in many developing countries. One of the pollution concerns at dumpsites is the emission of methane, which has been identified as a green house gas. In order to determine the surface emission of methane at an informal settlement built on a former dumpsite, six sampling events were conducted using the enclosed chamber method. The results showed that the surface emission of methane in the study area is high, with a maximum mean value of 2441.8 g/m2/h; this surface emission is between one to four orders of magnitude higher than the maximum values found in other published studies. The total mass of methane emitted at the site is also two orders of magnitude higher compared to studies within a similar area. But it is 177 and 3.5 times lower than in other studies conducted in South Korea and India, respectively. High variation in the surface emission of methane may be a result of the changing conditions in this urban environment.