Heavy Metal in Paddy Soil and its Bioavailability in Rice Using In Vitro Digestion Model for Health Risk Assessment

Abstract

Rice ingestion is one of the major pathways for heavy metal bioaccumulation in human. This study aimed to measure the heavy metal content of paddy soils and its bioavailability in paddy grain in order to assess the health risk. In total, 10 rice samples (50 g each) of paddy plants were harvested from the Selangor and Terengganu areas of Malaysia to assess the bioavailability of heavy metal (As, Cd, Cu, Cr, and Pb) using the in vitro digestion model of Rijksinstituut voor Volksgezondheid en Milieu. The bioavailability of heavy metal concentrations in rice samples were analyzed using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The findings showed the bioavailability of heavy metal concentrations was decreased in the order Cr > Cu > Pb > As > Cd. Chromium was found to be the most abundant bioavailable heavy metal in cooked rice, which was the result of its high content in paddy soil. Hazard Quotient values for the bioavailability of the heavy metal studied were less than one indicating no non-carcinogenic health risks for adults and children. Meanwhile, the total Lifetime Cancer Risk exceeded the acceptable value showing a potential of carcinogenic health risk for both adults and children. The application of in vitro digestion model in assessing bioavailability of heavy metal produces a more realistic estimation of human health risks exposure. However, a regular monitoring of pollution in Selangor and Terengganu areas is crucial since the exposure of heavy metals through rice consumption poses the potential non-carcinogenic and carcinogenic health risk to the local residents.

Biofortification of Oryza sativa L. with agri-food waste to improve the dietary value of crops

“…As major concern in soil and food pollution, specifically in the rice cultivation, is heavy metals such as cadmium, mercury, lead and arsenic. These contaminate the soil and subsequently make plants toxic (Zulkafflee et al, 2019). All tested waste combinations used to immobilize/remove heavy metals from rice soils had a very significant effect on cadmium and lead content.…”

“…The important thing is that the higher the content of this waste provided the higher efficiency. The high sorption performance of hazelnut shells in removing heavy metals has been revealed (Zulkafflee et al, 2019). Their results showed a higher removal potential of hazelnut shell of about 98% for cadmium and 97% for lead from contaminated solutions.…”

Quantitative Analysis and Human Health Risk Assessment of Heavy Metals in Paddy Plants Collected from Perak, Malaysia

“…60 mesh sieve). To extract heavy metals from the soil samples, 1 M ammonium acetate (NH 4 CH 3 COO) at pH 7 was used [ 10 , 15 ]. Briefly, 10 g of soil were mixed with 50 mL of NH 4 CH 3 OO in a conical flask and the mixture was shaken for 1.5 h. After centrifuge at 3000 rpm for 30 min, the samples were filtered through a 0.45 µm syringe filter (Millipore, Merck, Kenilworth, NJ, USA).…”

“…In relation to heavy metals contamination, several studies have been performed on paddy soils and paddy plants collected from plantation areas in Kedah [ 10 , 11 , 12 , 13 , 14 ]. Besides Kedah, the plantation areas in other rice-producing states, including Sabah and Selangor were also studied for heavy metals contamination on paddy soils and rice [ 15 , 16 , 17 ]. However, there is a lack of data for the safety of rice regarding to heavy metals contamination in Perak, a state with major tin mining and production in Peninsula Malaysia during the late nineteenth century.…”

Understanding Potential Heavy Metal Contamination, Absorption, Translocation and Accumulation in Rice and Human Health Risks

“…Other than estimating HRA by mathematical models, in vitro digestion models can be conducted in order to determine the bioaccessible form of trace element and heavy metals [174,175]. This model involves the total fraction of trace element and heavy metal concentration present in a specific environmental field within a time period and uptake through the indirect ingestion by organisms [176].…”