Evaluating genotoxic effects of plants exposed to heavy metals and polycyclic aromatic hydrocarbons at dumpsite, mechanic workshop and metal scrap site in Lagos

Abstract

Soil contamination from heavy metals and polycyclic aromatic hydrocarbons (PAHs) from dumpsite, automobile mechanic workshop and metal scrap sites pose human and ecological health risks. This study assesses the levels of heavy metals and PAHs in soils from these sites and their effects on the DNA yield and fragmentation of native plants around there. The DNA yield and fragmentation were compared to those obtained from non-polluted sites (control). DNA of the plants species, Musa acuminata (banana), Jatropha curcas (Barbados nut), Carica papaya (pawpaw), Axonopus compressus (carpet grass), Sida acuta (wireweed), and Eleucine indica (crabgrass grass) for polluted sites and control were analyzed using Gel electrophoresis. Soil heavy metals; copper (Cu), zinc (Zn), lead (Pb) and chromium (Cr) were evaluated from dumpsite, metal area and mechanic workshop using inductively coupled plasma-atomic emission spectrometry (ICP-AES). Polycyclic aromatic hydrocarbons were also determined from soils of the polluted sites using the GC/MS spectrophotometry. The result obtained from the DNA analysis showed that DNA yield and fragmentation of the polluted plants had higher indices than the controls which shows that heavy metals and polycyclic aromatic hydrocarbons affect the DNA of the plants. The effects of the pollutants on DNA of polluted plants had more smearing in their tissue than non-polluted plants. Heavy metals evaluation showed that zinc level was the highest in all the study sites; dumpsite, metal area and mechanic workshop (5.146 mg/kg, 2.709 mg/kg and 1.990 mg/kg respectively) than the control (p<0.05). Chromium was the least present (0.022 mg/kg, 0.018 mg/kg and 0.002 mg/kg respectively). The results of this study indicate that dumpsite, mechanic workshop and metal scrap sites are potential sources of PAH and toxic metal, which can pose serious human health and ecological risks.

Comparative analysis of heavy metals concentration in soil and vegetable (Solanum lycopersicum) collected from two sampling sites (Farmland and Dumpsite) and the effect on plant DNA

“…The present findings was in line with the work of [18] and [13] As revealed in this study, there was no mutation in the DNA constituents of S. lycopersicum collected from both the dumpsite and farmland. This observation was different from the results gotten by [19] which showed that plant in polluted sites had more DNA yield and fragmentation than those from non-polluted sites. Also, the findings of [19] indicated that dumpsite, mechanic workshop and metal scrap sites are potential sources of toxic metals, which can pose serious human health and ecological risks.…”

“…This observation was different from the results gotten by [19] which showed that plant in polluted sites had more DNA yield and fragmentation than those from non-polluted sites. Also, the findings of [19] indicated that dumpsite, mechanic workshop and metal scrap sites are potential sources of toxic metals, which can pose serious human health and ecological risks. However, the work of [20] indicated that solid waste pollution gave the highest reduction in DNA and RNA content of Olive plants.…”

Comparative Analysis of Heavy Metals Concentration in Soil and Vegetable (Vernonia amygdalina) Collected from Two Sampling Sites (Farmland and Dumpsite) and the Effect on Plant DNA

“…In contrast to the present observation, Weixuan et al [15] reported that there were heavy DNA methylation changes in rice. According to Mustapha et al [14], the DNA content of plants collected from polluted and control sites in their study differs per site. This was not so in this study.…”

“…"The use of plants' DNA as bioindicators of genetic toxicity of environmental pollutants such as heavy metals has been reported in several studies" [13]. Mustapha et al [14] assessed "the levels of heavy metals in plant and soils from dumpsite, mechanic workshop and metal scrap site in Lagos and their effects on the plants using their DNA as biomarker. Their findings indicated that plant in polluted sites had more DNA yield and fragmentation than those from non-polluted sites; more smearing of DNA was also identified in polluted plants than those from control sites".…”

Histopathological effects and biomarker response of earthworms, Eisenia fetida, after exposure to crude oil contaminated soils

“…In the last few decades, soil pollution has vastly increased owing to the intensive industrial and agricultural activities, overpopulation, urban waste and atmospheric deposition causing decrease in soil fertility, modification of soil structure, disturbance flora and fauna balance in the soil, accumulation of pollutants in the crops, and contamination of groundwater [1][2][3]. These chemical pollutants include heavy metals, pesticides, herbicides, ammonia, petroleum hydrocarbons, polychlorobiphenyl, dibenzo-p-dioxins/dibenzofurans, nitrate, mercury, and naphthalene [4,5]. Globally, petroleum-related activities have raised concerns about the adverse effects of contamination of petroleum products on the environment [6].…”