Evaluating the potential health risk of toxic trace elements in vegetables: Accounting for variations in soil factors

Abstract

Vegetable crop consumption is one of the main sources of dietary exposure to toxic trace elements (TEs). A paired survey of soil and vegetable samples was conducted in 589 agricultural sites in the Youxian prefecture, southern China, to investigate the effect of soil factors on the accumulation of arsenic, cadmium, mercury, and lead in different vegetables. A site-specific model was developed to estimate the health risk from vegetable consumption. The TE concentration varied in different plant species, and rape can be cultivated in contaminated areas for its potential use in restricting the transfer of TE from soil to edible plant parts. The accumulation of TEs in vegetables was governed by multiple factors, mainly element interaction, metal availability (extractable CaCl fraction), and soil pH. Soil Zn may promote Cd accumulation in vegetables when soil Cd/Zn ratio>0.02. Cadmium is a major hazardous component. About 80.8% of the adult populations consuming locally produced vegetables had a daily Cd intake risk above the safe standard. Among investigated vegetables, radish is potentially hazardous for populations because of its high consumption rate and high Cd content but low Zn accumulation. The consumption of radish cultivated in highly acidic soil (4<pH≤5) and high Cd contamination (CaCl-Cd=1.0mgkg) had a significant probability (89.4%) to be above the safe standard; while this risk was significantly decreased to 8.9% in soil of near-neutral pH (6<pH≤7). The wide range of TE concentrations and soil factors suggests that a site-specific risk assessment is needed for better and safer vegetable production.

Bioaccessibility and Human Exposure Assessment of Cadmium and Arsenic in Pakchoi Genotypes Grown in Co-Contaminated Soils

“…The average shoot As concentrations were 0.03 mg kg −1 under L-C soil, and 0.06 mg kg −1 under H-C soil. These results were consistent with the previous reports [ 14 , 15 ].…”

“…Soil samples were air dried, ground and passed through 10, 80, or 100 mesh stainless steel sieves in accordance with different analysis procedures. Basic soil characteristics of representative samples were then measured according to the procedures described by Liu et al [ 15 ] and Khan et al [ 35 ]. Soil samples were defined as low level co-contaminated soil (L-C soil), that had a total Cd concentration of 0.61 mg kg −1 , a total As concentration of 35.0 mg kg −1 , a soil pH of 6.3, organic matter of 1.4 g kg −1 , total N of 1.6 g kg −1 , and total P of 3.1 g kg −1 .…”

“…Pakchoi ( Brassica chinensis L.) is an important leafy vegetable consumed around the world, being among the 10 most important consumed vegetables in East, Northeast and Southeast countries, and having been introduced successfully in Europe, America and Australia, is increasing in prominence in Western diets [ 13 ]. Previous studies reported that among vegetable species, pakchoi is more vulnerable to Cd and As in contaminated soils [ 14 , 15 ]. Thus, developing of technologies that lower the risk of Cd and As through the food chain, and pakchoi in particular, is an urgent task.…”

Foliar application of seed water extract of Nigella sativa improved maize growth in cadmium-contaminated soil

“…Cadmium causes negative impacts on all life forms in the soil and moves into harvested parts of plants; thus, enters the food chain [22,23]. Vegetables consumptions contributes 70-80% of total Cd intake in humans [24][25][26], which cause serious health hazards [27]. Grazing or ingesting the Cd-polluted fodder by animals and subsequently consumption of milk and meat products cause Cd exposure in human beings [25].…”

Distribution, pollution, bioaccumulation, and ecological risks of trace elements in soils of the northeastern Qinghai-Tibet Plateau

“…Both natural and anthropogenic factors affect the distribution of trace elements and anthropogenic source is usually a main contributor (Lee et al, 2011). Trace elements including heavy metals and rare earth elements (REEs) have gained public attention in recent decades due to the relatively high concentrations detected in food, water, and soils (Li and Ji, 2017;Magesh et al, 2017;Yang et al, 2017).…”