Ni In Rice Research Articles

Bioaccumulation and human health risk assessment of chromium and nickel in paddy rice grown in serpentine soils

The natural abundance of Cr and Ni in serpentine soils is well-known, but the food safety of rice grown in these hazardous paddy soils is poorly understood. The study evaluated the bioaccumulation of chromium (Cr) and nickel (Ni) in rice (Oryza sativa) grown in serpentine-derived paddy soils in the Philippines. Surface soil (0-20 cm) samples were collected and characterized across three (i.e., Masinloc, Candelaria, and Sta. Cruz) paddy areas in Luzon Island, Philippines. At least 3 to 4 whole rice plants at mature stage were uprooted manually in each sampling point where the soil samples were collected. The total Cr and Ni concentrations in rice (i.e., roots, shoots, and grains) and soil, soil physicochemical properties, bioaccumulation factor (BAF), translocation factor (TF), and the hazard quotients (HQ) were determined. Results revealed that Cr and Ni in rice were accumulated mostly in the roots. Although paddy soils had elevated total Cr and Ni concentrations, the BAF and soil-to-root TF values for Cr and Ni were < 1. In terms of human health risks, results further revealed low risk for both male and female Filipino adults as HQ values for Cr and Ni were < 1. While it is safe to consume rice grown in the area in terms of Cr and Ni dietary intake, more studies are necessary to understand the dynamics and bioavailability of these heavy metals in other crops and drinking water from tube wells in these areas in order to provide a more holistic human health-based assessments and to ensure consumer safety in serpentine areas. In addition, a more reliable data on Cr and Ni speciation in serpentine soils and crops is critically important. Further studies are also needed to understand the contribution of bioavailable heavy metals in improving the soil health to achieve food safety.

Safety Assessment of Rice Planting in Soil Cadmium Geological Anomaly Areas in Southwest Guangxi

To evaluate the safety of rice planting in cadmium geological anomaly areas, 41 natural soil, 479 paddy soil, and 432 rice samples were collected in southwestern Guangxi. The contents of Cd, Cu, Ni, and Zn and soil physical and chemical properties were measured. The single factor pollution index method (Pi) was used to evaluate the degree of contamination of the sample, and correlation analysis were used to explore the main factors affecting the heavy metal content in rice. The results showed that ① soil pH of the paddy field was 6.8; the organic matter content was 39.00 g·kg-1; the risk screening value was based on the soil environmental quality standards for soil pollution risk control and control of agricultural land (GB 15618-2018), the exceeding standard rates of Cd, Cu, Ni, and Zn in soil were 60.75%, 2.09%, 0.83%, and 1.88%. ② The over-standard rates of Cd and Ni in rice were 9.03% and 4.39%, respectively. Considering straw as raw material for feed and organic fertilizer, the corresponding over-standard rates of Cd were 6.94% and 1.16%. ③ Correlation analysis showed that soil pH, organic matter, total heavy metal, and available content were the main factors affecting the content of heavy metals in rice. Cd and Ni in the study area all exhibited certain over-standard phenomena, and the low-accumulation rice varieties could be planted to reduce heavy metal content in rice.

Non-carcinogenic health risk assessment of nickel in agricultural products and drinking water in an e-waste dismantling area of Qingyuan City, Guangdong Province

Vegetables, rice, eggs and drinking water samples were collected from e-waste dismantling area of Qingyuan City, Guangdong Province. Nickel (Ni) was analyzed in each sample, and the non-carcinogenic health [the daily intake (DI) and hazard quotient (HQ)] of each sample was evaluated. In this e-waste dismantling area, the contents of Ni in rice and eggs were (0.46±0.24) and (0.16±0.13) μg/g, which were higher than those in the control area [the contents of Ni in rice and eggs were (0.17±0.03) and (0.02±0.02) μg/g, respectively] (both P values<0.05). The DI values of rice, vegetable, eggs, and drinking water were (3.61-5.86), (1.75-2.99), (0.11-0.24), and (0.08-0.12) μg·kg(-1)·day(-1), respectively. The HQ values were 0.180-0.290, 0.090-0.150, 0.005-0.010, 0.005-0.006, respectively. Although the HQ values of rice, vegetable, eggs, and drinking water were all lower than 1, which was an acceptable level. However, considering the possibility of combined exposure of heavy metals, the non-carcinogenic health risks of Ni in the e-waste dismantling area should still be concerned.

Epidemiological Study on Metal Pollution of Ningbo in China.

Background: In order to search for effective control and prevention measures, the status of metal pollution in Ningbo, China was investigated. Methods: Nine of the most common contaminating metals including lead (Pb), cadmium (Cd), copper (Cu), iron (Fe), manganese (Mn), chromium (Cr), nickel (Ni), zinc (Zn), and mercury (Hg) in samples of vegetables, rice, soil, irrigation water, and human hair were detected using inductively coupled plasma-mass spectrometry (ICP-MS). Three different districts including industrial, suburban and rural areas in Ningbo were studied through a stratified random sample method. Results: (1) Among all of the detected vegetable samples, Cd exceeded the standard limit rates in industrial, suburban and rural areas as high as 43.9%, 27.5% and 5.0%, respectively; indicating the severity of Cd pollution in Ningbo. (2) The pollution index (PI) of Cd and Zn in soil (1.069, 1.584, respectively) suggests that soil is slightly polluted by Cd and Zn. Among all samples, metal contamination levels in soil were all relatively high. (3) A positive correlation was found between the concentrations of Pb, Cd and Cu in vegetables and soil; Pb, Cu, Cr and Ni in vegetables and irrigation water, as well as, Cu and Ni in rice and irrigation water; and, (4) Higher Pb and Cd concentrations were found in student scalp hair in both industrial and suburban areas compared to rural areas. (5) Hg and Pb that are found in human scalp hair may be more easily absorbed from food than any of the other metals. Conclusions: In general, certain harmful metal pollutions were detected in both industrial and suburban areas of Ningbo in China.

Nickel accumulation in paddy rice on serpentine soils containing high geogenic nickel contents in Taiwan.

We investigated the extractability of nickel (Ni) in serpentine soils collected from rice paddy fields in eastern Taiwan to evaluate the bioavailability of Ni in the soils as well as for demonstrating the health risks of Ni in rice. Total Ni concentrations in the soils ranged were 70.2-2730mg/kg (mean, 472mg/kg), greatly exceeding the natural background content and soil control standard in Taiwan. Available Ni concentration only accounts for <10% of total soil Ni content; 0.1N HCl-extractable Ni was the more suitable index for Ni bioavailability in the soil to rice than was diethylenetriaminepentaacetic acid (DTPA)-extractable Ni. The accumulation ability of rice roots was much higher than that of its shoots; however, compared with those reported previously, our brown and polished rice samples contained much higher Ni concentrations, within the ranges of 1.50-4.53 and 2.45-5.54mg/kg, respectively. On the basis of the provisional tolerable Ni intake for adults recommended by the World Health Organization (WHO), daily consumption of this rice can result in an excessive Ni intake.

Nickel in milled rice (Oryza sativa L.) from the three main rice-producing regions in China

ABSTRACTNickel (Ni) concentrations in milled rice obtained from China and their variations among different provinces and varieties, as well as associated health risks, were investigated. Results showed that the mean Ni concentration in milled rice was 0.49 ± 0.51 mg/kg, which was much higher than reported in United Kingdom, French and Iranian cereals. There were significant variations (P < 0.05) of Ni concentrations in milled rice among different provinces and among varieties in the same province. According to the dietary risk assessment, the mean values of the target hazard quotient for chronic risk ranged from 1.24 to 1.46 for 2–4, 4–7 and 7–11-year-old children, and all values of margin of exposure for hypersensitivity risk were considerably below 10 for all age groups, indicating that the current dietary exposure to Ni in rice is of concern for 2–11-year-old children and Ni-sensitised individuals. It is essential to establish a continuous monitoring programme to control Ni contamination in rice.

Modeling transfer of heavy metals in soil–rice system and their risk assessment in paddy fields

Many studies have been conducted on model transfer in soil–plant systems. However, relatively little information is available on modeling metal transfer in soil–rice system and associated risk assessment in real paddy fields. Based on a random sampling method from Nanxun, Shengzhou and Wenling in Zhejiang province, China, 15 pairs of rice and the corresponding soil samples were respectively collected for analysis of heavy metals and soil pH. The results showed that the accumulation ability of rice for different heavy metals was significantly different (p Zn > Cu > Ni > Cr > Pb. The relationships of heavy metals in rice with those in soil, along with soil pH, were well described by linear regression models. Except for Pb, the contents of most metals in rice were positively correlated with those of the soil. Soil pH was negatively correlated with the contents of Cd, Zn and Ni in rice, and positively correlated with Pb in rice; however, it had less effect on Cr and Cu. Based on risk reference dose (RfD), the risk assessment data indicated that the rice grown in Zhejiang paddy fields does pose some potential Cd and Cr contamination risk to food safety; rice in Shengzhou posed light Ni risk.