Assessing the Potential Risk of Heavy Metal Exposure from Moringa oleifera and its Phytoremediation Potential
摘要
Moringa oleifera (moringa) is widely recognized for its medicinal properties and capacity to hyperaccumulate certain environmental contaminants. Moringa was introduced into a highly contaminated residential area in Kabwe, Zambia, one of the most heavily polluted cities globally, for nutritional and medicinal use. However, no prior assessment has evaluated whether moringa grown under these conditions poses a risk of heavy metal exposure to the residents. This study assessed the potential health risks associated with consuming moringa cultivated in contaminated soils and examined whether its hyperaccumulation tendencies limit its safety for dietary or medicinal use. In addition, the phytoremediation potential of moringa in the field was assessed. Plant and soil samples were collected from 60 households and one pre-Kindergarten through 12th grade school located in a neighborhood adjacent to a former lead–zinc mine. Element concentrations were quantified using X-ray fluorescence (XRF) and atomic absorption spectrometry (AAS), and mean concentrations were compared using one-way ANOVA. Results indicate that moringa cultivated in contaminated environments has the potential to accumulate heavy metals to concentrations that may pose health risks. Under the contaminant conditions observed in this study, moringa consumption should not exceed 1 g/day. Furthermore, although moringa demonstrated some capacity for phytoremediation, it was not sufficiently effective as a standalone remediation species. These findings suggest that moringa should be used in combination with other established phytoremediation plants to meaningfully reduce heavy metal contamination in affected areas.