Comparative assessment of trace metals in soils associated with casket burials: Towards implementing green burials

Abstract

Casket burials has been one of the most prevalent methods of disposing of the dead for several centuries. However, its increasing use in many countries has engendered serious environmental and epidemiological concerns due to documented evidences of leaching of toxic metals and pathogens as human remains and grave contents decompose over time. In this paper, a comparative trace element study of surface soils samples collected from two municipal cemeteries located in Macao SAR (China) and Akure (Nigeria) was undertaken to investigate their contamination potential. Soil contamination assessment based on index of geo-accumulation indicate that the soils associated with the Macao cemetery have been significantly contaminated with Ag, Cd, Hg, Pb, Se and Zn, while that of Akure site did not show significant pollution. From a comparative perspective, it was observed that the levels of Pb and Zn observed in the Macao cemetery soils was higher than the maximum values reported for selected cemetery soils in Brazil, South Africa, Rwanda, and the United States of America. For the Akure site, none of the samples showed significant pollution as the levels of trace elements were within the uncontamination threshold. Inconsistent levels of trace metals levels observed in the soils of the two cemeteries is likely to have resulted from the differences in the number of burials, soil characteristics, type of materials used for construction of coffins. The findings therefore suggest the need to improve awareness of eco-friendly burials to protect and conserve the environment.