Phytoavailability of Cadmium (Cd) to Pak Choi (Brassica chinensis L.) Grown in Chinese Soils: A Model to Evaluate the Impact of Soil Cd Pollution on Potential Dietary Toxicity

Abstract

Food chain contamination by soil cadmium (Cd) through vegetable consumption poses a threat to human health. Therefore, an understanding is needed on the relationship between the phytoavailability of Cd in soils and its uptake in edible tissues of vegetables. The purpose of this study was to establish soil Cd thresholds of representative Chinese soils based on dietary toxicity to humans and develop a model to evaluate the phytoavailability of Cd to Pak choi (Brassica chinensis L.) based on soil properties. Mehlich-3 extractable Cd thresholds were more suitable for Stagnic Anthrosols, Calcareous, Ustic Cambosols, Typic Haplustalfs, Udic Ferrisols and Periudic Argosols with values of 0.30, 0.25, 0.18, 0.16, 0.15 and 0.03 mg kg−1, respectively, while total Cd is adequate threshold for Mollisols with a value of 0.86 mg kg−1. A stepwise regression model indicated that Cd phytoavailability to Pak choi was significantly influenced by soil pH, organic matter, total Zinc and Cd concentrations in soil. Therefore, since Cd accumulation in Pak choi varied with soil characteristics, they should be considered while assessing the environmental quality of soils to ensure the hygienically safe food production.

Bioaccumulation of heavy metals in soil and selected food crops cultivated in Kogi State, north central Nigeria

“…Similarly, Salazar and Pignata (2014) reported high level of lead exceeding national and international norms in soils and native plants in Córdoba, Argentina. Uptake and transfer of heavy metals through food crops are affected by the level of metals in soils, soil properties, pH, age of food crop, food crop types and species (Rafiq et al 2014;Xu et al 2015;Yang et al 2015). It becomes imperative to evaluate heavy metal uptake by food crops and assess the potential health risks.…”

Effect of Biochar Amendment on Bioavailability and Accumulation of Cadmium and Trace Elements in Brassica chinensis L. (Chinese Cabbage)

“…Mehlich-3 extractable Cd was found to be more improved indicator and used as soil Cd thresholds in Chinese cabbage for potential dietary toxicity (Rafiq et al, 2014). The effects of biochar on metal adsorption varied with the source material used to produce it and the type of metal.…”

“…Alfisol is an important soil type and occupied about 1.25 million square km, about 13% of the land area in China (about the same percentage occurred as Alfisols in U.S.) (Xiao, 1992). Plants grown in Cd contaminated Alfisol soil accumulated higher Cd contents because of relatively higher percentage of sand in this soil which enhance Cd accumulation and ultimately decreased eco-physiological components such as plant growth, by interfering metabolic processes, mineral nutrition and photosynthetic activity (Sebastian & Prasad, 2014;Rafiq et al, 2014).…”

Phenylalanine ammonia-lyase activity and anthocyanin content in different varieties of lettuce under the cadmium influence

“…It is known that lettuce (Lactuca sativa L.) and other leafy vegetables being dietary multivitamin daily cultures of human nutrition [14] with a rapid biomass growth could be considered as potential heavy-metal accumulators [15,16]. Despite…”

“…Phenylalanine ammonia-lyase (PAL, L-Phenylalanine Ammonia-Lyase EC 4.3.1.24) is a regulatory enzyme of the seconda ry metabolism compound biosynthesis that cataly zes the primary reaction of reverse deamination of L-phenylalanine amino acid to the trans-cinnamic acid [11,12]. Therefore the PAL in the plant orga nism can play an extremely important role to run the resistance mechanisms against the toxic effects of stress factors, including cadmium [10,13].It is known that lettuce (Lactuca sativa L.) and other leafy vegetables being dietary multivitamin daily cultures of human nutrition [14] with a rapid biomass growth could be considered as potential heavy-metal accumulators [15,16]. Despite…”