Assessment of metal contamination of soils exposed to car tires burning in Ngaoundere (Cameroon) [Evaluation de la contamination métallique des sols exposés à l'incinération des pneus d'automobiles dans la ville de Ngaoundéré (Cameroun)]

The purpose of this study is to evaluate the metal contamination of soils exposed to the burning of car tires. thus,30 soil samples were collected in small wells and around them in three sites where the incineration activity takes place. the samples were analyzed by icp-aes. the results show that the total concentrations of heavy metals in soils differ depending on the depth,the site and the metal considered. these elements vary (mg / kg) 37 730-59 920 for fe; 105.70 to 28 060 for zn; 9.48 to 257.10 for ni; 4.88 to 291.90 for cu; 41.65 to 521.50 for cr; 1.92 to 208.50 for pb and cd nd ~ 5.23. the analyzes of heavy metals reveal that all these elements have high levels in the studied soils compared to the reference values used. to assess the level of contamination of the soils,the enrichment factor (ef) and the index of geo-accumulation (igeo) were calculated. thus,it was noted that with the exception of ni whose enrichment is moderate,cr,cu,pb,cd present an ef that reaches the moderate to strong level of enrichment. zn is the most enriched metal in soils with extreme ef and this is confirmed by (igeo) which presents extreme contamination for that element. detection in these soils of metals at very high level is a risk for the populations that consume plants grown on them.