Heavy Metal Bioaccumulation in Rice from a High Geological Background Area in Guizhou Province, China

Abstract

Long-term exposure to high levels of heavy metals can lead to a variety of diseases. In recent years, researchers have paid more attention to mining and smelting areas, industrial areas, and so forth, but they have neglected to report on high geological background areas where heavy metal levels are higher than China’s soil environmental quality standard (GB 15618-2018). In our study, an investigation of heavy metals in paddy soil and rice in the high background area of Guizhou Province was carried out, and the factors affecting the absorption and utilization of heavy metals in rice were discussed. A total of 52 paddy soil and rice samples throughout the high geological background of Guizhou, China, were collected, and concentration(s) of arsenic, cadmium, copper, lead, and zinc were analyzed. The arithmetic mean values of paddy soil heavy metals were 19.7 ± 17.1, 0.577 ± 0.690, 40.5 ± 32.8, 35.5 ± 32.0, and 135 ± 128 mg kg−1 for arsenic, cadmium, copper, lead, and zinc, respectively. Most of the heavy metals’ contents in the soil were above the soil standard value. The highest content of cadmium was 15.5 times that of the soil standard value. The concentration(s) of arsenic, cadmium, copper, lead, and zinc in rice were 0.09 ± 0.03, 0.01 ± 0.01, 1.57 ± 0.69, 0.002 ± 0.003, and 11.56 ± 2.61 mg kg−1, respectively, which are all lower than those specified by Chinese food safety standards (GB 2762-2017). The results and discussion show that the bioavailability, pH, and soil organic matter are important factors that affect the absorption of heavy metals by rice. According to the consumption of rice in Guizhou Province, the risk of eating rice was considered. The results revealed that the hazard quotient is ranked in the order of copper > zinc > cadmium > arsenic > lead, and there is little risk of eating rice in the high geological background area of Guizhou Province. These findings provide impetus for the revision and improvement of this Chinese soil environmental quality standard.

Analysis of lead, arsenic, and cadmium concentrations in instant noodles within the Canadian market

“…Rice noodles have been found to contain higher concentrations of heavy metals as compared to wheat noodles because rice crops require a lot more water for irrigation than wheat crops, which causes heavy metals to accumulate in the grains in larger amounts (Thielecke & Nugent, 2018;Kong et al, 2018). Arsenic, particularly, is absorbed at a much larger scale than other heavy metals during rice cultivation due to its natural properties (Thielecke & Nugent, 2018).…”

“…Arsenic, particularly, is absorbed at a much larger scale than other heavy metals during rice cultivation due to its natural properties (Thielecke & Nugent, 2018). Bioaccumulation of heavy metals in crops is dependent on soil properties, bioavailability of heavy metals during crop cultivation, pollution levels, water quality, and mining practices (Kong et al, 2018). Thus, good agricultural practices and good manufacturing processes, to monitor and control water and soil quality during crop cultivation, can protect the public from consuming dangerously high levels of As, Pb, and Cd (Thielecke & Nugent, 2018;Kong et al, 2018).…”

Distribution of Potential Harmful Trace Elements and Potential Ecological Risk in the Jiulongchi Wetland of Fanjing Mountain, Southwest China

“…The industries in Guizhou Province are based on the enriched resources, taking energy, raw material, machinery and electronics with flue-cured tobacco, cigarettes and wine as predominant outputs [3]. Those industrial production processes have led to industrial problems, especially PHTEs pollution [4,5].…”

Distribution of Selected Heavy Metals Bioaccumulation in Various Parts of Indigenous Rice (Bokilong, Ponsulak and Taragang) in North Borneo

“…Amendments of soil pH have been intensively investigated to increase soil pH and for improving rice yields (Abdul Hamid et al, 2018). One of the main reasons is to reduce heavy metal bioavailability in soil because soil pH also affected soil heavy metal bioavailability (Kim et al, 2016;Kong et al, 2018). Many agricultural land in Malaysia also has a high concentration of Ferrum oxides formed by the natural weathering process.…”

“…Observation of different paddy cultivation practices by flooding method and non-flooding method had resulted in nonflooding soil had a higher concentration of heavy metal bioavailability even on non-polluted soil as compared to flooding method (Cattani et al, 2008;Slamet-Loedin et al, 2016;Hamdan et al, 2019). Local climate and soil physicochemical properties influence the heavy metal bioavailability in soil (Sanjeevani et al, 2013;Kong et al, 2018).…”