The concentration and distribution of selected heavy metals (Pb, Cd, Cu and Zn) in soils collected from the rice fields of MADA in Kedah, Malaysia

Abstract

Abstract. The present study was carried out to determine the concentration and distribution status of some heavy metals (Pb, Cd, Cu and Zn) in the paddy field soil fractions of MADA in the state of Kedah, Malaysia. Five replicate samples were randomly collected from five paddy fields in the MADA area of Jitra. The heavy metals in the soil were extracted using sequential extraction method that was presented by Badri and Aston [1], which consisted of four different fractions using different reagents. The first fraction of extraction is the easily leachable and freely exchangeable fraction (ELFE), which uses ammonium acetate (NH 4 CH 3 COO). The second fraction is acid reduction fraction (AR), which uses hydroxylamine chloride (NH 2 OH_HCl), while the third fraction of extraction called the organic oxidation fraction (OO) was carried out using the combination of hydrogen peroxide (H 2 O 2 ), and ammonium acetate (NH 4 CH 3 COO). The last fraction called the resistant fraction uses concentrated nitrate acid (HNO 3 ) and perchlorate acid (HClO 4 ). Generally, all the paddy soils in this study contained low levels of Pb, Cd, Cu and Zn concentration compared to the other paddy soils. The result showed that the concentration of heavy metals in the studied area was in the following decreasing order i.e.: Pb > Zn > Cu > Cd. The results also showed that the concentration of heavy metals in the paddy soil fractions were mainly concentrated in the RR fraction except for Pb, which was at the highest level in the OO fraction, whilst Cd was more evenly distributed throughout the whole soil fraction. In general, Pb was the highest metal concentration found in the OO fraction followed by Zn in the RR fraction of the soil fractions.

Effect of Wastewater Irrigation on Trace Metal Accumulation in Spinach (Spinacia oleracea L.) and Human Health Risk

“…All metal values in the present research identified below permissible limits for all treatments. Findings of Alrawiq et al [32] showed a higher amount of metals than the presented values in this study except for Cd. Many studies performed in Pakistan reported on the high concentration of trace metals in vegetables irrigated with industrial water or sewage sludge.…”

Heavy Metal Contamination in Oryza sativa L. at the Eastern Region of Malaysia and Its Risk Assessment

“…The significant higher level of As concentration can be found in stem of paddy plants located in the KBP sampling sites and paddy leaf located in PPP sites. These parts are highly accumulated with As, indicating high availability of As in the soil in addition to its mobility within the plants [ 24 ]; concentration may be also influenced by various anthropogenic practices such as farming tractors, chemical fertiliser and pesticide usage [ 29 ]. The arsenic distribution from the root to grain of the paddy plant from the three plots (PPP1, PPP2, PPP3) ranged from 0.078 to 0.087 mg/kg for As concentration, in which the concentration of As in PPP sites was highest in leaf and grain of paddy plants.…”

“…The elevated level of Cr in the rice grain from the Pasir Puteh area may be a consequence of anthropogenic contamination in the vicinity of the paddy field. Although Cr is considered an essential element, excessive levels in food or plants may cause toxicity to animals and humans [ 24 ].…”

“…Since rice is consumed as a staple food by the majority of the world’s population, including Malaysia, it is crucial to assess the levels of heavy metals in paddy soils and paddy plants, and to elucidate the mechanisms of this heavy metal uptake, as continuous intake of contaminated rice poses adverse health risks. Known as the Rice Bowl of Malaysia, Kedah is the major rice-producing state in Malaysia and many studies concerning heavy metals have focused on the plantation areas in this state [ 7 , 17 , 24 , 25 , 26 ]. In addition, the other states known for paddy plantation, including Perlis, Sabah and Selangor, have also been studied for heavy metal contamination in paddy soil and plants [ 26 , 27 , 28 , 29 ].…”