title: Effect of cadmium accumulation on mineral nutrient levels in vegetable crops: potential implications for human health.
abstract: Consumption of vegetables is often the predominant route whereby humans are exposed to the toxic metal Cd. Health impacts arising from Cd consumption may be influenced by changes in the mineral nutrient content of vegetables, which may occur when plants are exposed to Cd. Here, we subjected model root (carrot) and leaf (lettuce) vegetables to soil Cd concentrations of 0.3, 1.5, 3.3, and 9.6 μg g(-1) for 10 weeks to investigate the effect of Cd exposure on Cd accumulation, growth performance, and mineral nutrient homeostasis. The findings demonstrated that Cd accumulation in lettuce (20.1-71.5 μg g(-1)) was higher than that in carrot (3.2-27.5 μg g(-1)), and accumulation exceeded the maximum permissible Cd concentration in vegetables when soil contained more than 3.3 μg g(-1) of Cd. There was a marked hormetic effect on carrot growth at a soil Cd concentration of 3.3 μg g(-1), but increasing the Cd concentration to 9.6 μg g(-1) caused decreased growth in both crops. Additionally, in most cases, there was a positive correlation between Cd and the mineral nutrient content of vegetables, which was due to physiological changes in the plants causing increased uptake and/or translocation. This may suggest a general mechanism whereby the plant compensated for disrupted mineral nutrient metabolism by increasing nutrient supply to its tissues. Increased nutrient levels could potentially offset some risks posed to humans by increased Cd levels in crops, and we therefore suggest that changes in mineral nutrient levels should be included more widely in the risk assessment of potentially toxic metal contamination. Graphical abstract The Cd concentration (μg g-1 in dry matter) in the root, shoot and translocation factor (TF) of Cd from root to shoot in the carrot and lettuce, and the percentage of root Cd to the gross Cd contents (%) in carrot (C) and lettuce (D) exposed to soil Cd (0 (control), 1, 3, and 9 μg g-1) for 70 days. Values are means ± SD (n = 5).
authors.affiliation: College of Resources and Environment, Southwest University, Chongqing, China.|Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China.
authors.forename: Danping
authors.initials: D
authors.lastname: Yang
authors.affiliation: Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China. guozq@scsio.ac.cn.|Department of Life and Environmental Sciences, Faculty of Science and Technology, Bournemouth University, Fern Barrow, Poole, Dorset, BH12 5BB, UK. guozq@scsio.ac.cn.
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Guo
authors.affiliation: Department of Life and Environmental Sciences, Faculty of Science and Technology, Bournemouth University, Fern Barrow, Poole, Dorset, BH12 5BB, UK.
authors.forename: Iain D
authors.initials: ID
authors.lastname: Green
authors.affiliation: College of Resources and Environment, Southwest University, Chongqing, China. xdt@swu.edu.cn.
authors.forename: Deti
authors.initials: D
authors.lastname: Xie
mesh_terms: D018552:Daucus carota / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D006801:Humans; D018545:Lactuca / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D008670:Metals / Q000378:metabolism* / Q000633:toxicity; D008903:Minerals / Q000378:metabolism; D018515:Plant Leaves / Q000378:metabolism; D018517:Plant Roots / Q000378:metabolism; D018520:Plant Shoots / Q000378:metabolism; D018570:Risk Assessment; D012989:Soil Pollutants / Q000378:metabolism* / Q000633:toxicity; D014675:Vegetables / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*
chemical_list: D008670:Metals; D008903:Minerals; D012989:Soil Pollutants
keywords: Bioaccumulation; Heavy metals; Nutritional element homeostasis; Tolerance index; Translocation factor; Vegetables