Relationships between Cd concentrations in different vegetables and those in arable soils, and food safety evaluation of vegetables in Taiwan

Abstract

The cadmium (Cd) accumulation capacity of various vegetables and the relationship between Cd concentrations in edible parts of vegetables and those in soils were assessed by conducting field experiments at Cdcontaminated sites in northern and central Taiwan. In addition, to thoroughly assess Cd concentrations in vegetables and to understand the food safety of vegetables in Taiwan, 2257 paired vegetable and surface soil samples were collected from major vegetable production areas for Cd concentration analysis. According to the bioconcentration factors calculated, the Cd accumulation capacity varied considerably among the vegetable species tested, and the order of the five vegetables with the highest capacities is peanut (Arachis hypogaea L.) > amaranth (Amaranthus tricolor L.) > spinach (Spinacia oleraceae L.) > gynura (Gynura bicolor DC.) > okra (Hibiscus esculentus L.), whereas the order of the five vegetables with the lowest capacities is bitter gourd (Momordica charantia L.) < cucumber (Cucumis sativus L.) < asparagus bean (Vigna unguiculata (L.) Walp. ssp. sesquipedalis (L.) Verdc.) < snap bean (Phaseolus vulgaris L.) < sponge gourd (Luffa cylindrica Roem.). We derived 29 soil-plant transfer models of Cd for individual vegetable species based on available pools of the Cd, manganese (Mn), zinc (Zn), copper (Cu) and iron (Fe) concentrations; soil pH; and cation exchange capacity (CEC). According to the derived models, the available Cd, Mn and Zn concentrations, and pH, served as the main factors affecting Cd concentrations in the edible parts of vegetables, whereas the CEC and available Cu and Fe concentrations are less important factors. The data of previous studies and those of this study from major vegetable production areas, including 30 vegetable crops, were used to evaluate the safety of vegetables in Taiwan. The results indicated that the percentage of vegetables with Cd concentrations exceeding the regulatory concentration was 0.54%; therefore, the food safety concern is low. However, 9.8, 1.0, 0.9 and 0.6% of amaranth, cabbage (Brassica oleracea L. Capitata Group), Chinese cabbage (Brassica pekinensis Skeels.) and carrot (Daucus carota L.), respectively, had Cd concentrations in the edible parts exceeding the regulatory concentration. Particular attention should be paid when planning production areas for these vegetables. We recommend cultivating peanuts in fields with a soil Cd concentration < 0.33 mg kg −1. The bioconcentration factors and soil-plant transfer models derived in this study might serve as assessment tools for planning farming areas for these vegetables.

Uncovering the Genetic of Cadmium Accumulation in the Rice 3K Panel

“…Air-dried soil samples were passed through a 2 mm sieve, homogenized, and stored in plastic vessels. The basic properties of the test soil, namely soil pH [ 50 ], organic matter [ 51 ], cation exchange capacity [ 52 ], the available Cd concentration [ 53 ] and the total Cd concentration [ 54 ], were analyzed.…”

Molecular-Assisted Breeding of Cadmium Pollution-Safe Cultivars

“…Leafy vegetables such as pakchoi, Chinese leek, water spinach, and lettuce have higher Cd accumulations in their edible parts compared to other vegetables belonging to the cucurbitaceae and solanaceous families. , In a study involving 18 plant species, Indian mustard and oilseed rape showed significantly higher Cd accumulation capacity in the same contaminated soil, with 10- and 66-fold higher accumulations compared to other species . Among 29 vegetable species, the top 5 Cd accumulators are peanut, amaranth, spinach, gynura, and okra, while the bottom 5 Cd accumulators are bitter gourd, cucumber, asparagus bean, snap bean, and sponge gourd . Similarly, another study reported the highest Cd accumulation in water spinach and the lowest accumulation in sweet pea among 28 vegetable species, with a maximum variation of 110-fold and 175-fold at two soil Cd levels (1 and 2 mg/kg) …”

Potential Risk of Consuming Vegetables Planted in Soil with Copper and Cadmium and the Influence on Vegetable Antioxidant Activity

“…Cd was considered to be the most toxic (0.00-16.8 mg/kg), and Cu was found to contaminate the central area (4.43-217 mg/kg). In Taiwan, Lin et al [33] also reported soil contamination by Cd in Taoyuan (1.90-19.4 mg/kg) and Taichung (0.48-3.89 mg/kg). These results suggest that health risks should be taken into consideration for the food safety of local crops.…”