Evaluation of Heavy Metal Contamination in Paddy Plants at the Northern Region of Malaysia Using ICPMS and Its Risk Assessment

Abstract

Heavy metals from natural and anthropogenic sources accumulate in soil and plants and as a consequence represent important environmental contamination problems. Nevertheless, food safety issues and adverse health risks make this one of the most serious environmental issues. The aim of the present study was to assess heavy metal contamination in the paddy plants from the northern area of Malaysia using Inductively Coupled Plasma Mass Spectrometry (ICPMS) and its risk assessment. In total, the heavy metals (As, Cd, Cu, Cr, and Pb) of the samples of paddy plants harvested from Kedah areas were extracted using an acid digestion method, while the heavy metals for soil samples using ammonium acetate. The heavy metal concentrations were then analysed using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The enrichment (EF) and translocation factors (TF) of heavy metals were calculated, and health risk assessment (HRA) was performed. The EF values for heavy metals from the soil to roots, roots to stems, stems to leaves, and stems to grains followed the order Cu > As > Cr > Cd > Pb, whereas Cr and Pb were characterized by greater TF values from stem to grain than the other elements. The average daily dose (ADD) for both children and adults is below the safe value intake for each of the studied elements. The combined hazard index (HI) of five elements was beyond the acceptable value (HI >1). The carcinogenic risk, as exemplified by lifetime cancer risk (LCR), indicated that single exposure to As or Cr, in both adults and children, was greater than 10−4. The total cancer risk (CRt) resulting from multiple exposure to carcinogenic elements exceeded the acceptable value (CRt >1 ×10−4) in both adults and children. Overall, exposure to heavy metals through rice consumption poses potential non-carcinogenic and carcinogenic health risks to the local residents in the northern area; thus, regular monitoring of pollution in the area is crucial.

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).…”

“…60 mesh sieve). Heavy metals in different parts of the paddy plants were extracted using acid digestion method [ 10 ]. To 1 g of each sample powder, 10 mL of 69% nitric acid (HNO 3 ) was added.…”

“…For quality assurance, all the laboratory equipment were soaked with 10% HNO 3 . A standard solution was analysed after every 10 experimental samples, and each soil and rice sample were analysed in triplicate together with Certified Reference Material (CRM) IRMM 804 in the range of 90.5% to 102.4% [ 10 ].…”

“…Kedah is the state with largest paddy plantation areas in Malaysia. 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 ].…”

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

“…The toxicity of metals in terms of toxicological effects may vary in each person. One way to predict their bioaccumulation and transformation is to develop a mathematical model for HRA when associated with heavy metal contamination, especially in soil [134].…”