Fruits and vegetables contaminated with particles of heavy metals: A narrative review to explore the use of electromagnetic fields as an alternative treatment method

Figures & data

Figure 1. Interaction between fruits and vegetables, heavy metals and health (adopted from a study of A. Kumar et al., 2019).

Table 1. Current methods for treatment of heavy metals in plants

References	Contaminant	Plant type (agricultural product)	Treatment methods
Noor et al. (2022)	All heavy metals-metal-polluted soil.	Horticultural plants: Fruits and vegetables.	In situ low-technology approach
Nathan et al. (2022)	Metal ions in the soil.	Kiwifruit, apple, banana, cucumber, orange and potato.	Biosorption
Shu et al. (2021)	Cadmium (Cd).	Grape juice, tomato juice, apple juice, cucumber juice, and carrot juice.	Microbial-lactic acid bacteria strains
Ravindran et al. (2020)	Lead (Pb), mercury (Hg), manganese (Mn) and cadmium (Cd).	Vegetables.	Thermostable biosurfactant
Tavakoli-Hosseinabady et al. (2018)	Lead (Pb), cadmium (Cd) and nickel (Ni).	Leafy edible vegetables.	Absorption by Apricot Pit Shell
Bora et al. (2022)	Arsenic (As), cadmium (Cd) and lead (Pb).	Fruits and vegetables	Vinegar solution

Figure 2. Varying concentrations of Cu, Fe, Zn and Cr in different vegetables (Qureshi et al., 2016).

Table 2. Summary characteristics of the studies conducted on the fruit and vegetables contaminated with heavy metals

Author	Study title	Methodology	Results	Conclusion
Dickin et al. (2016)	A review of health risks and pathways for exposure to wastewater use in agriculture.	Literature review of related studies.	Despite increased chemical concerns related to fast urbanization and industrialization that might affect the nature and distribution of wastewater contaminants, a geographic breakdown found a focus on microbiological contaminants in particular locations including Sub-Saharan Africa and Southeast Asia.	Future studies should consider multiple exposure routes, long-term health effects, and expand the range of pollutants studied, especially in areas heavily dependent on wastewater irrigation, to enable a thorough understanding of the health risks associated with wastewater use in agriculture.
Elbagermi et al. (2014)	Monitoring of heavy metal content in fruits and vegetables collected from production and market sites in the Misurata Area of Libya.	Laboratory analysis.	Mango, melon, spinach, and banana fruits had the highest average amounts of Pb, Cu, Zn, Co, Ni, and Cd.	The analyzed heavy metals’ estimated daily intake levels are lower than those recommended by the FAO and WHO.
Koleayo et al. (2017)	Nutritional composition and heavy metal content of selected fruits in Nigeria.	Laboratory analysis.	The WHO’s permitted thresholds for Ni and Cr were exceeded in apples taken from various sites.	Ni and Cr excesses can result in lung cancer, stomach discomfort, skin rashes, and kidney and liver damage.
Mawari et al. (2022)	Heavy metal accumulation in fruits and vegetables and human health risk assessment: findings from Maharashtra, India.	Laboratory analysis.	The mean levels of the selected heavy metal in fruits and vegetables were as follows: Pb (0.170.38 mg/kg)> Hg (0.060.09 mg/kg)>Cd (0.020.007 mg/kg) > As (0.002–0.003 mg/kg). Garlic had the most heavy metal concentration, followed by potatoes.	The amount of heavy metals in the soil was less than permitted. The accumulation of heavy metals such as As, Cd, Hg and Pb in fruits and vegetables resulted from wastewater irrigations.
Prabhat et al. (2019)	Heavy metals in food crops: health risks, fate, mechanisms, and management.	Literature review of related studies.	The main causes of heavy metal contamination in soil culture systems in industrialized countires are industrial effluents and sewage sludge as fertilizers. While the primary cause of food crop contamination in developing nations is irrigation with poorly treated wastewater.	Human health, food safety, and environmental contaminants are all interconnected.

Table 3. Studies related to health effects from heavy metal exposure

Heavy metals	Applications	Health effects	Authors	Study title
Lead (Pb)	Plastic products, gasoline, car exhaust, and batteries	Cardiovascular and neurotoxic effects	(A. Kumar et al., 2019)	Fungal phytoremediation of heavy metal-contaminated resources
Zinc (Zn)	Fertilizers	Fatigue, nausea, drowsiness, and weakened immune system	Mishra et al. (2019)	Heavy metal contamination: An alarming threat to environment and human health
Chromium (Cr)	Pesticide and paints pigment	Cancer, ulcers, and nephritis	Onakpa et al. (2018)	A review of heavy metal contamination of food crops in Nigeria
Arsenic (As)	Wood products and herbicides	Cancer, changes in reproduction and development	Skalnaya et al. (2019)	Serum levels of copper, iron, and manganese in women with pregnancy, miscarriage, and primary infertility
Cadmium (Cd)	Pigments fertilizers	Fragile bones, cancer-causing endocrine disruptors, and lung damage	Sharma et al. (2014)	Heavy metal levels in adolescent and maternal blood: Association with risk of hypospadias.
Mercury (Hg)	Catalysts, rectifiers and electric switches	Renal and lung death due to neurological and immunological conditions	Manzoor et al. (2018)	Heavy metals in vegetables and their impact on the nutrient quality of vegetables: A review.
Copper (Cu)	Electronics, and wood preservative	Chronic anemia, liver cirrhosis, renal damage, and brain damage	Henriques et al. (2017)	Bioaccumulation of Hg, Cd and Pb by Fucus vesiculosus in single and multi-metal contamination scenarios and its effect on growth rate

Figure 3. Magnetic field treatment for plants exposed to heavy metals (applicable to both fruit and vegetable plants) to enhance tolerance and produce reactive oxygen species (ROS) (adopted from a study of Radhakrishnan, 2019).

Kumar, A., Chaturvedi, A. K., Yadav, K., Arunkumar, K. P., Malyan, S. K., Raja, P., Kumar, R., Khan, S. A., Yadav, K. K., Rana, K. L., Kour, D., Yadav, N., & Yadav, A. N. (2019). Fungal phytoremediation of heavy metal-contaminated resources: Current scenario and future prospects. In Recent advancement in white biotechnology through fungi (pp. 437–461). Springer International Publishing. https://doi.org/10.1007/978-3-030-25506-0_18

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