Soil Cadmium Concentration Research Articles

Meteorological effects on trace element solubility in Mississippi coastal wetlands

Trace elements (TEs) vary in toxicity and should be closely monitored to manage their accumulation in marine organisms, which may pass on to the food web. This study utilizes the National Oceanic and Atmospheric Administration’s (NOAA), Data Integration Visualization Exploration and Reporting (DIVER), National Centers for Environmental Information (NCEI), and Drought Monitor Systems to acquire arsenic (As), cadmium (Cd), chromium (Cr), lead (Pb), and zinc (Zn) concentrations in marsh soils along the Mississippi Gulf Coast area using the precipitation and drought data for the two sampling periods in 2010 and 2011. Results revealed that Zn had a significantly high correlation (r = 0.80 and <em>p</em> &lt; 0.05) between soil concentrations and daily rainfall amounts, whereas Pb concentrations in soil were shown to occur after heavy storms. There was also significant variation between the months for Cd, Cr, and Pb, over the sampling periods. Arsenic remains relatively stable and statistically similar in the sediment averaging 21.09 µg/kg. Coastal soils were significantly higher in Cd and Cr concentrations in 2010 (28.89 µg/kg for Cd and 28.91 µg/kg for Cr) compared to 2011 (both 9.16 µg/kg). The trace elements, Cd and Cr showed negative correlation (r = −0.63 and −0.27) to increasing drought intensities. Most of these responses can be explained by a redox process where TEs were sequestered or released as solids and subsequently becomes saturated or dried out. It was observed that soils in Mississippi’s Gulf Coast study areas have the ability to be a sink or reservoir during various weather conditions thereby entrapping or releasing TEs, which becomes more available to organisms.

Mobility of Cadmium in Distributed Desert Soil Column Amended by Sewage Sludge

The main aim of this research is to predict the movement of cadmium (Cd) ions in sewage sludge-amended soil columns. Sewage sludge impact on the mobility of cadmium was studied using disturbed soil columns, to assess the vertical movement of Cd in desert soil treated with different rates of sewage sludge, i.e., (T1= 0, T2= 20, T3=40, and T4= 60 ton/hectare). The obtained results showed that the physiochemical properties of the studied soil had improved significantly due to sewage sludge addition. Soil organic matter and porosity increase the water-holding capacity and structure of studied soil. Sewage sludge had the ability to increase soil fertility.&#x0D; In contrast, the excess of some heavy metals in the amended soil is the negative impact of using sewage sludge. Cadmium concentrations were greater at a higher rate (T4) of sludge treatment (14.2 mg/kg). According to the findings, the sewage sludge addition to the tested columns yielded considerable Cd concentrations in their leachates. Whereby, leachates of the soil column amendment with 60 ton/hectare contained higher Cd concentration (3.03 mg/l).&#x0D; Moreover, after leaching the soil cadmium concentration differ according to the addition rate, leading to this trend: (T1) &lt; (T2) &lt; (T3) &lt; (T4). Distribution of Cd in soil columns after the leaching process distributed on the soil layers. Overall, Cd movement in sludge-amended soil was correlated with organic matter and pH with r= (0.71439 and 0.0.94886) and r= (0.70965 and 0.99047) respectively.

Cadmium in New Zealand agricultural soils

ABSTRACTI summarised cadmium concentrations from soil samples collected by the fertiliser industry between 2006 and 2015, and from soil samples collected by regional councils. Using these data, a statistical model was used to estimate soil cadmium concentrations on agricultural land within each territorial authority. Across New Zealand, most territorial authorities (56 of 66), including all the South Island, had mean soil cadmium concentrations below 0.6 mg Cd/kg. The highest mean soil cadmium values on agricultural land were in the Otorohanga and Matamata-Piako districts (0.90 and 0.89 mg Cd/kg, respectively). In these districts, around 1% of properties were estimated to have mean soil cadmium in excess of 1.8 mg Cd/kg. The fertiliser industry requires that cadmium concentrations in phosphate fertiliser are below a voluntary limit of 280 mg/kg P. The mean cadmium concentration in fertiliser samples taken between 2003 and 2015 was 184 mg Cd/kg P, 66% of the voluntary limit.

Ecological Assessment of the Content of Cadmium in Soils and Crops in Southwestern Regions of the Central Chernozemic Zone, Russia

It is found that in Belgorod oblast during 2010–2014, cadmium mainly came into agrocenoses with organic fertilizers (0.4 g/ha, or 73.9%) and ameliorants (0.116 g/ha, or 21.4%). The lowest total content of cadmium in the A horizon (0.22 mg/kg) was noted in meadow-chernozemic soil (Greyzemic Stagnic Chernic Phaeozem (Clayic, Pachic)) developed on old alluvial calcareous deposits, and its highest content (0.42 mg/kg) was found in ordinary chernozem (Haplic Chernozem (Clayic, Pachic)), where loess-like clay is the main parent rock. Virgin leached chernozem (Luvic Сhernozem (Loamic, Pachic)) formed on loess-like loam, contained 0.33 mg Cd/kg in the A horizon, which almost coincided with the mean content of this element (0.32 mg/kg) in the plow layer of leached chernozems on reference plots. No exceeding of the tentative permissible concentration of cadmium was revealed in arable soils. In crops, the content of cadmium was highest in sunflower seeds (0.086 mg/kg) and soya beans (0.072 mg/kg), and lowest in peas (0.032 mg/kg) and white lupine beans (0.013 mg/kg). The biological adsorption factor varied within the range from 0.97 (while lupine beans) to 10.8 (sunflower seeds) for target agricultural crops and from 0.41 (while lupine straw) to 4.63 (soya straw) for side products.

The effect of hydro and proline seed priming on growth, proline and sugar content, and antioxidant activity of maize under cadmium stress.

We tested the effect of seed hydro- and proline-priming on cadmium (Cd) tolerance in maize plants. Soil supplemented with two concentrations of cadmium was used for the investigation. Cadmium content, fresh and dry mass, shoot length, leaf length and width, chlorophyll, proline, sugar and protein content, and antioxidant potential in 4-week-old plants were analysed. Cadmium content in soil and maize shoots was determined by flame atomic absorption spectrometry. Accumulation of Cd was observed for all plants, and highest Cd concentration was recorded in seedlings grown from proline-primed seeds with no visual signs of Cd toxicity. In proline-primed plants, increase in leaf length, photosynthetic pigments, and sugar and proline content as well as changes in antioxidant enzyme activities was recorded. Results obtained in this study suggest that proline-priming of maize seeds induces activation of defensive mechanisms, such as proline and sugar synthesis, which in return alleviates Cd toxicity on maize growth with increased Cd accumulation comparing to control plants.

Pollution Status of Heavy Metals in Spent Oil-Contaminated Soil in Gwagwalada

The pollution status of some selected heavy metals namely: Pb, Fe, Zn, Cu, Cr, Ni and Cd, in spent oil-contaminated soil were investigated. The soil samples were obtained from different spots of the automobile mechanic workshop, wet digested and the concentrations of the heavy metals in the soil digest determined using Atomic Absorption Spectrophotometer (AAS). The concentration of Pb was significantly higher (p&lt;0.05) than the concentrations of each of the other six heavy metals while cadmium had the least concentration. In most of the sampling spots analyzed, the concentrations Cd were below the detection limit of the instrument used. The order of the concentrations of the heavy metals were Pb&gt; Fe&gt; Zn&gt; Cu&gt; Cr&gt; Ni&gt; Cd and Fe &gt; Cr &gt; Zn&gt; Pb&gt; Cu&gt; Ni&gt; Cd for the spent oil-contaminated and control soils respectively. The concentration of iron, cadmium, copper, nickel and zinc in the control soil were significantly lower (p&lt;0.05) than the concentration of iron, zinc and lead in the oil-contaminated soil. The concentration of Pb exceeded the limits of both the background and intervention lead value set by DPR (Department of Petroleum Resources) of Nigeria. The contamination and potential ecological factors of Zn, Cu, Fe, Cr and Cd were categorized low except Pb which was categorized as having very high contamination factor and moderate potential ecological risk factor. The entire studied spots showed moderate degree of contamination. The potential risk index of the heavy metals ranged from 44.23 to 51.91, which had a low grade category; implying that the heavy metals have caused low harm to the soil of the workshop. This paper gives information on the present status of heavy metals in the soil and the need for continuous monitoring so as to avert further contamination of this workshop.

Risk assessment of lead and cadmium exposure from electronic waste recycling facilities in Southern Thailand

Electronic waste (e-waste) contains a variety of toxic substances that can be released into the surrounding environment and adversely affects human health when a primitive recycling process is used. This research aims to investigate the concentrations of lead and cadmium in soil and in the blood of workers at e-waste recycling facilities, to examine the correlation between the concentrations of lead and cadmium in soil and in the blood of the workers and to assess the health risks from the exposure of lead and cadmium in the soil at the e-waste recycling facilities. The results of this study showed that the concentrations of lead and cadmium found in the soil were 1.150 ± 0.00–2866.97 ± 31.54 and 0.181 ± 0.00–0.200 ± 0.00 mg/kg, respectively. The concentrations of lead were over the standard limit in Thailand. Moreover, the concentration of lead in the soil correlated to that in the blood of the workers. The concentration of lead in the men’s blood was two times higher than in the women’s blood. Lead and cadmium concentrations in smokers’ blood were higher than that in the non-smokers. The determinations of lead and cadmium exposure among workers at e-waste recycling facilities were 1.54 × 10−6–6.28 × 10−3 and 9.05 × 10−8–2.27 × 10−7 mg/kg, respectively. The greatest Hazard Quotient (HQ) of lead exceeded 1.74, signifying that high exposure of lead might pose a potential health risk to workers in e-waste recycling facilities.

Cadmium phytoextraction potential of king grass (Pennisetum sinese Roxb.) and responses of rhizosphere bacterial communities to a cadmium pollution gradient.

Screening for tolerant and high biomass producing plants is important for phytoextraction efforts in remediating agricultural soils contaminated by heavy metals. We carried out a greenhouse experiment involving a soil cadmium (Cd) concentration gradient (0.1, 0.5, 1, 2, 4, and 8mgkg-1) to assess growth and phytoextraction capacity of king grass (Pennisetum sinese Roxb.) in soils contaminated by Cd and to explore changes in diversity and structure of rhizosphere soil bacterial communities in response to long-term Cd pollution. A significant positive relationship was observed between Cd concentrations in P. sinese stems, leaves, and roots and soil Cd concentration. The highest Cd concentrations in shoots and roots were 28.87 and 34.01mgkg-1, respectively, at 8mgkg-1of soil Cd supply. Total extraction amounts of Cd in P. sinese were 0.22-1.86mgplant-1 corresponding to treatment with 0.5-8mgkg-1 Cd. Most of the Cd was stored in shoots, and the largest accumulation was 1.56mgplant-1 with 54.02g dry shoot weight. After phytoextraction, changes in rhizobacterial community composition were found with different levels of Cd application, whereas there were no clear trends in diversity and richness. Results of this study show the feasibility of P. sinese in accumulating Cd and provide support for its application in remediation of soil moderately contaminated by Cd.

Effects of Arbuscular Mycorrhizal Fungi on Accumulation of Heavy Metals in Rhizosphere Soil

&lt;p&gt;&lt;em&gt;The rhizosphere soil arbuscular mycorrhizal fungi will affect the absorption of heavy metal substances by the host plants. The effects of the arbuscular mycorrhizal fungi are inhibitory and conversion effects. The type and quantity of AMF fungi are different, and there are also differences in the absorption of arbuscular mycorrhizal fungi in the rhizosphere soil. Changes in the accumulation of heavy metals will affect the growth of arbuscular mycorrhizal fungi in the rhizosphere soil. In this paper, a preliminary investigation is made as to whether the AMF fungus number will affect the absorption of heavy metal Cd. Experiments show that with the increase of soil spores, the available cadmium content of soil also tends to increase.&lt;/em&gt;&lt;/p&gt;

Air-Filled Porosity as a Key to Reducing Dissolved Arsenic and Cadmium Concentrations in Paddy Soils.

Simultaneous suppression of rice ( L.) uptake of As and Cd is challenging because these toxic elements are immobilized under contrasting redox conditions. Given the notion that oxygen diffusion governs redox conditions in temporarily drained paddy soil, we assume that the key to simultaneous suppression of dissolved As and Cd concentrations is air-filled porosity (AFP) of soil. The objectives of this study were to reveal relationships between AFP and dissolved As and Cd concentrations in paddy soils and to identify the optimum water management, in terms of AFP, for simultaneous reduction of As and Cd. Dissolved As and Cd concentrations were determined in soil cores collected at different depths and times during rice growing seasons. Dissolved As concentrations were appreciable (>3 µg L) only when AFP was below a threshold value of 0.04 to 0.10 m m, suggesting that dissolved As was rapidly immobilized once AFP exceeded the threshold value on drainage. Dissolved Cd concentrations were roughly proportional to AFP, with higher concentrations associated with lower soil pH. Although dissolved As concentrations tended to be low in soil samples with high dissolved Cd concentrations and vice versa, both concentrations were low when AFP was slightly above the threshold value for As immobilization. The results suggest that dissolved As and Cd can be simultaneously kept at low levels by appropriate water management practices that produce AFP slightly above the threshold value for As immobilization.

Achievability of Municipal Solid Waste Compost for Tea Cultivation with Special Reference to Cadmium

Municipal solid waste compost (MSWC) is quite often used for soil amendment in agricultural crops and yet little is known about its effect on tea (Camellia sinensisL.) cultivation. This study investigates the effect of MSWC application on cadmium (Cd) concentrations in soil, tea plants, and infusions. Different doses of MSWC are added to soil with two Tocklai vegetative (TV) tea clones (TV1 and TV23) for 2 years in pot experiments. Several fractions of Cd in amended soils, biomass yield, and Cd content in different parts of tea plants and in tea infusions are measured. Several indexes related to risk assessment are also calculated. The geo‐accumulation index values of Cd in soil amended with MSWC ranges from −1.74 to 3.12, indicating class 0 (practically uncontaminated) to class 4 (heavily contaminated) contamination level. Average daily intakes (ADI) of Cd through tea infusion produced from tea plant amended with MSWC are 8.9 × 10−6and 9.2 × 10−6 mg kg−1per body weight and day for men and women, respectively. These values are much lower than those given in the Joint FAO/WHO Provisional Tolerable Monthly Intake Guideline for Cd. The non‐carcinogenic risk values (also called hazard quotient) for Cd, estimated from the ADI values, are found to be 1.78 × 10−2and 1.94 × 10−2 mg kg−1per day for men and women, respectively, suggesting no health hazard. The results suggested the possibility of management of MSW through composting and the feasibility of compost application for tea cultivation.

Heavy metal contamination in soils and vegetables and health risk assessment of inhabitants in Daye, China.

ObjectiveThis study was performed to evaluate the state of heavy metal contamination in soil and vegetables and assess the health risk of inhabitants in the mine-affected area and area far from the mine (reference area) in Daye, China.MethodsThe heavy metal concentrations in soil and vegetable samples were detected by inductively coupled plasma mass spectrometry. Residents’ exposure parameters were obtained through a questionnaire survey. A health risk assessment model recommended by the United States Environmental Protection Agency was used to evaluate the residents’ risk of oral exposure.ResultsThe copper, lead, cadmium, and arsenic concentrations in soil and in vegetables were higher in the mine-affected area than in the reference area. The health risk of residents in the reference area was within the acceptable range (hazard index < 1, carcinogen risk < 10−4). In the contaminated area, however, the mean hazard index was 2.25 for children and 3.00 for adults, and the mean carcinogen risk was 4.749 × 10−4 for children and 0.587 × 10−4 for adults.ConclusionsPotential health risks exist for inhabitants near the mine area. Cadmium and arsenic should be paid more attention as risk sources.

Influence of the use of EM preparations on the content of heavy metals in the soil

The effect of microbiological preparations Baikal EM-1, Emochky-fertility, Orhanik-balance, Vermisol, Tseliulad, Biofosforyn on reduction of heavy metals (lead, cadmium, copper and zinc) concentration in soil. The coefficient of technogenic concentration of heavy metals in the soil for the use of EM preparations has been calculated. The prospect of using technologies of effective microorganisms for reducing soil pollution by heavy metals has been substantiated.

Enhanced electrokinetic remediation of lead- and cadmium-contaminated paddy soil by composite electrolyte of sodium chloride and citric acid

The aim of this study was to inquire about the removal efficiencies of lead and cadmium in paddy soil by a composite electrolyte of sodium chloride and citric acid under electrokinetic remediation. The experiment was operated in a plexiglass tank, which was divided into one soil column (length × width × height = 20 cm × 5 cm × 5 cm) and two electrode chambers (length × width × height = 6 cm × 5 cm × 5 cm). In this paper, the composite electrolyte (sodium chloride + citric acid) which combined the merits of two different chemicals was investigated for electrokinetic remediation of lead- and cadmium-contaminated paddy soil under a voltage gradient of 1.5 V/cm during a 20-day treatment. The total concentrations of lead and cadmium in the initial soil were 940.83 and 4.51 mg/kg, respectively. As sodium chloride was solubilized in solution, a number of Na+, Cl−, OH−, and H+ ions were generated that could dissolve some of Pb and Cd in soil to form Cd–Cl and Pb–Cl. When the lead- and cadmium-contaminated paddy soil was implemented with 0.1 M sodium chloride, the total removal efficiencies of lead and cadmium were 23.10 and 27.94%, respectively, which were little higher than those implemented with deionized water. Citric acid was not only used to control pH, but it can also combine with metals to form soluble M-citrate. When sodium chloride was mixed with citric acid in electrokinetic (EK) remediation, high redox potential was obtained that forced most of the metals to migrate out from soil. The overall removal efficiencies of lead and cadmium were increased from 56.85 and 62.26% with single citric acid electrolyte to 80.37 and 90.86% with composite electrolyte of sodium chloride and citric acid, respectively. Eventually, the residual concentrations of lead and cadmium in the soil were only 184.70 and 0.41mg/kg, respectively, which met the demand of agricultural production and human health requirements. Citric acid + sodium chloride treatment poses less environmental risk than inorganic acid (HCl, HNO3, and H2SO4). There is good synergistic effect of sodium chloride and citric acid during the EK remediation process. Thus, citric acid + sodium chloride is considered as an effective electrolyte to remove lead and cadmium from paddy soil.

Assessing social vulnerability to biophysical hazards in the Kumasi metropolis, Ghana

This study assesses social vulnerability to hazards by analyzing the nature of biophysical hazards, and the characteristics of exposures, susceptibilities and adaptive capacities in Kumasi. A mixed method approach was used to collect primary data from farms and nearby markets. Water, soil, and plant samples were collected and tested for total coliforms and cadmium. Primary dataset was also collected from farmers and vendors using structured interview guide and from key informants through in-depth interviews. The analysis shows that several pressures residing within the coupled social-ecological system are threats to the health and livelihood of the farmers and vendors. The concentration of cadmium and total coliform in irrigation water, soil, and plants exceeded the WHO/FAO acceptable standards. Bio-toxins in plants were also found to be potentially high. However, the degree of exposure to these stressors and the strength of response and adaptive capacities were determined to be dependent on position within the urban agriculture value chain, type of plant, and socio-demographic characteristics. The study concludes that pollution of irrigation water, soil, and plant is an issue of environmental concern in the urban agriculture system and requires concerted efforts of all stakeholders to address. It is recommended that there should be frequent monitoring of the quality of irrigation water, soil, and produce from urban farms and markets to assess their physical, chemical, and microbial properties and possibly initiate remedial measures where necessary. Government policies must also focus on building the resilience of urban farmers and vendors to reduce their vulnerability to biophysical hazards.

Electrochemical Determination of the Levels of Cadmium, Copper and Lead in Polluted Soil and Plant Samples from Mining Areas in Zamfara State, Nigeria

&lt;p class="PaperAbstract"&gt;&lt;span lang="EN-GB"&gt;The concentrations of lead, copper and cadmium in soil and plant samples collected from Abare and Dareta villages in Anka Local Government Area of Zamfara State, Nigeria have been electrochemically determined. The study was carried out because of the high mortality of women and children under five, reported for these areas in June 2010. The cause was ascribed to the lead poisoning which has been related to the mining and processing of gold-containing ores. Linear sweep anodic stripping voltammetry technique was used with the glassy carbon working, Ag/AgCl reference and platinum auxiliary electrodes. Voltammetric peaks for lead, copper and cadmium that were observed at -495 mV, -19.4 mV and -675 mV, respectively, have formed a basis for construction of the corresponding calibration plots. The concentrations (in mg/kg) of lead, copper and cadmium in the soil samples were found in the ranges of 18.99−26,087.70, 2.96−584.60 and 0.00−1354.25, respectively. The concentration values for lead were far above already established USEPA (2002) and WHO (1996) maximum permissible limits for residential areas. The concentrations of lead, copper and cadmium in the food samples ranged between 5.70−79.91, 11.17−41.21 and 0.00−5.74 mg/kg. Several of these values are found well above the FAO/WHO limits of 0.1, 2 and 0.1 mg/kg, respectively. The results indicate that in addition to the lead poisoning, copper and cadmium poisoning may also be responsible for sudden and high mortality in this population.&lt;/span&gt;&lt;/p&gt;

Cadmium accumulation characteristics of floricultural plant Cosmos bipinnata

ABSTRACTThe artificially high soil cadmium (Cd) concentration screening method was used to screen Cd-hyperaccumulators from floricultural plants. Among the five species of floricultural plants screened, Cosmos bipinnata showed the characteristics of Cd-accumulators. A pot experiment was conducted to further study Cd accumulation characteristics of C. bipinnata. The results showed that the biomass, chlorophyll content, superoxide dismutase activity, peroxidase activity and soluble protein content of C. bipinnata first increased and later decreased with the increase in soil Cd concentration, but the carotenoid content and catalase activity of C. bipinnata reduced. Cd contents in roots, stems, leaves and shoots of C. bipinnata increased with increasing soil Cd concentration. When the soil Cd concentration was 50 mg kg−1, the Cd content in shoots was up to 112.62 mg kg−1, which was higher than the Cd-hyperaccumulator critical value. The root and shoot bioconcentration factors exceeded 1 in various Cd treatments, but the translocation factors were less than 1. When the soil Cd concentration was 50 mg kg−1, the Cd accumulation in shoots achieved the maximum of 224.30 μg plant−1. Therefore, considering the tolerance and accumulation of Cd, C. bipinnata is a Cd-accumulator that could be used to remediate Cd-contaminated urban soil.

Effects of long-term fertilizer applications on peanut yield and quality and plant and soil heavy metal accumulation

The status of essential and potentially toxic trace elements in soils and crops can be affected by long-term fertilization practices. This study aimed to investigate changes in peanut (Arachis hypogaea L.) yield and kernel quality, and changes in copper (Cu), zinc (Zn), lead (Pb), and cadmium (Cd) concentrations in soil and peanut kernels after 16 years of continuous cropping with different fertilization treatments. Five fertilization treatments were applied at a red soil site in Southeast China: chemical fertilizer (F) containing nitrogen, phosphorus, and potassium, F + trace elements (FT), pig manure (M), M + effective microorganisms (MB), and MB + trace elements (MBT). Properties of soil and pig manure, heavy metal contents in soil and peanut kernels, and the compositions of amino and fatty acids in kernels were determined. Application of pig manure significantly increased peanut biomass, kernel yield, and crude protein and total amino acid contents in kernels, but led to higher amounts of Cu, Zn, and Cd in soil and higher amounts of Zn and Cd in peanut kernels compared with that of chemical fertilizer. There should be greater concern about potential kernel Cd and Zn contaminations resulting from long-term application of pig manure contaminated with potentially toxic metals as an organic fertilizer.

Interactive effect of cadmium and zinc on chromium uptake in spinach grown in Vertisol of Central India

A pot culture experiment was conducted to study impact and interaction of multi-metals on growth, yield and metals uptake by spinach (variety All Green). Three levels of each chromium (0, 50 and 100 mg/kg), cadmium (0, 1 and 2 mg/kg) and zinc (0, 10 and 20 mg/kg) in combinations (total treatments 3 × 3 × 3 = 27) were applied in a Vertisol (5 kg). The results showed that increasing the concentration of chromium, cadmium and zinc in soil enhanced the respective metal concentrations in spinach root and shoot. When cadmium at 2 mg/kg along with chromium at 100 mg/kg soil was applied, chromium concentration and uptake were decreased in root and shoot. Meanwhile, zinc application had no significant effect on chromium uptake and concentration in spinach biomass. From the results, it was concluded that cadmium at higher dose had an antagonistic effect over chromium. On the other hand, in chromium, cadmium and zinc combinations particularly at their higher levels, a competition among each other was found. Therefore, the findings could be used as guidelines for controlling and management of heavy metals pollution in farmland.

Nitrate, arsenic, cadmium, and lead concentrations in leafy vegetables: expected average values for productive regions of Chile

ABSTRACTHigh arsenic (As), cadmium (Cd), lead (Pb), and nitrate (NO3−) concentrations in soil pose a risk for the human population and compromise food safety. The goal of this study was to obtain preliminary approximations for the expected mean values of As, Cd, Pb, and N-NO3 in three leafy vegetables (lettuce, spinach, and chard) grown in the central farming regions of Chile. Representative samples (n = 148) of these crops were collected from the Coquimbo, Valparaíso, and Metropolitana Regions. Water extraction and an ion-selective electrode were used to determine NO3− contents, while total As, Cd, and Pb contents were determined by atomic absorption spectroscopy. The recorded values were 23.8%, 59.2%, and 97.9% below detection limits for As, Cd, and Pb, respectively. Furthermore, As and Cd intake by leafy vegetables reached 0.26 and 2.30% of the daily intake levels estimated by Chilean authorities. The daily NO3− intake by leafy vegetables was 0.44 mg per kg of bodyweight per day (kgbw−1day−1), or 12% of the WHO-recommended intake. No analyses were performed for Pb due to highly left-censored data. While the recorded NO3−, As, and Cd concentrations in lettuce, spinach, and chard do not apparently pose a health risk, further detailed studies are suggested.