Bioaccumulation and translocation of heavy metals in different fruit plants with corresponding health risk assessments

Abstract

The contamination of crops, vegetables, and fruits with heavy and toxic metals has become one of the most severe environmentalpollution problems nowadays in many developingcountries like Bangladesh. Heavy metals can be released into terrestrial environment from natural and anthropogenic activities and accumulated in waterbodies and soil from which they can transfer intofruit plants through various pathways and thuscan adversely affect human health.In the present study, accumulation and mobilization status of various heavy metals and metalloids have been determined in water, arable soil, and different fruit plants grown in and around Dhaka Export Processing Zone (DEPZ) located in Savar, Dhaka. Total of tenmetals (Pb, Cd, Cr, Cu, Fe, Zn, Ca, Co, Ni, Mn) and 2 metalloids, (As and Se) have been analyzed in different parts (root, stem, leaves and edible parts) of three common fruits plants such as Guava (Psidium guajava), Pomelo (Citrus maxima), Banana (Musa paradisiaca) as well as in their growth media (water and soil). All metals and metalloids contents in the different environmental samples (fruits, soil, and water) were determined by using Atomic Absorption Spectroscopy (AAS) as well as Inductively Coupled Plasma Mass Spectrometry (ICP-MS).The distribution and transfer of heavy metals and metalloids from water and soil into different parts of various fruit plants were investigated accordingly.Different pollution indicessuch asHeavy metal transfer factor (TF), Estimated daily intake (EDI), Targethazard quotient (THQ), Hazard index (HI), Carcinogenic risk (CR) factor,Food pollution index (FPI), Soil threshold values and food safety (STV), Geoaccumulation index (Igeo), and Enrichment factor (EF)were analyzed to assess twelve heavy metals and metalloids contamination,their distribution and mobilization in irrigation water, arable soil, and in different parts of fruits plants.Pearson's correlation analysis wasapplied to identifycorresponding distributions of heavy and toxic metals in different fruit plants.Metals and metalloids concentrations found in the respective environmental samples were analyzed statistically by using Minitab software.Average concentrations of twelve different elements in water and soil were found to be in the order of: Ca > Fe > Zn > Cu > Mn > Cr > As > Pb > Ni > Co > Se > Cd and Fe > Ca > Mn > Zn > Pb > Cr > Ni > Cu > Co > As > Se > Cd respectively. Heavy metals contents found in water and soil were exceeded the permissible levels of WHO and USEPA suggesting metals pollution in the respective environment components. Different fruits plants showed variation in the uptake and deposition of heavy metals and metalloids and the average concentrations of different elements found in various fruits species followed the order of Ca > Fe > Mn > Cu > Zn > Pb > Cr > Ni > Se > Co > Cd > As.Evaluation of the mobilization of metals and metalloids in different parts of various fruits plants bodies revealed the occurrence of the highest accumulation of the elements in leaves whereas the lowest uptake of the respective metals was observed in the edible parts irrespective of the plant bodies. The extents of different heavy metals found in the edible parts of various fruitsplants was relatively higher than the tolerable limits recommended by FAO and WHO.Out of three sources, heavy metals and metalloids contents in soil were much higher than those observed in water and four parts of each of the three fruits plants bodies.The extents of Pb, Cr and Mn in three fruitspeciesmight cause highernon-carcinogenic risks as evidenced from the risks assessment data.Carcinogenic risks (CR) analysis data showed the range as E-04 < CR > E-06 which suggest that Cd, Cr and Ni enriched fruits could pose a considerable cancer risk for both adults and children The significant findings of this research work suggest that the study areais highly unsafe for growing fruits, crops, and vegetables as they accumulate and deposit excessivequantities of heavy metals and other elements which severely affect food safety and thus poses potential health risksto millions of people in Bangladesh. KEYWORDS: Fruits, Plant parts,Soil, Heavy Metals, Food pollution index,Transfer factor,Health Risks, DEPZ.