Cd Intake Research Articles

Five heavy metals accumulation and health risk in a traditional Chinese medicine Cortex Moutan collected from different sites in China

ABSTRACTThis study assessed the concentrations of five heavy metals Pb, Cd, Cr, Cu and Zn in both soil and a traditional Chinese medicine Cortex Moutan collected from 6 typical sites, growing this medicine, in China. The potential health risks associated with those heavy metals were also assessed. It is shown that Cd content in soils from five of the six sites was higher than the environmental Quality Standard for Soils of China (EQSS). The cortex from a copper tailings area in Tongling (marked as TLC) accumulated much higher amounts of heavy metals than the other sites. Calculated pollution index implied that the herbs in TLC were mildly contaminated by Pb, Cd, and Cu. Hazard quotient (HQ) indicated the intake of Pb, Cd, Cr, Cu, and Zn was safe by cortex consumption, but noncarcinogenic and carcinogenic risks of all metals in Cortex Moutan in hillside near the copper tailings (marked as TLB) and TLC were higher. The results suggested more attention should be paid to the planting area near the mining tailing, and in order to ensure the quality of the herbal medicines, the regions where this herb is grown should be at distance from the mining tailing area.

Arsenic and Other Elemental Concentrations in Mushrooms from Bangladesh: Health Risks.

Mushroom cultivation has been increasing rapidly in Bangladesh. Arsenic (As) toxicity is widespread in the world and Bangladesh faces the greatest havoc due to this calamity. Rice is the staple food in Bangladesh and among all the crops grown, it is considered to be the main cause of As poisoning to its population after drinking water. Consequently, rice straw, an important growing medium of mushrooms in Bangladesh, is known to have high As content. The objective of this study was, therefore, to determine the concentrations of As in mushrooms cultivated in Bangladesh and to assess the health risk as well. It also considered other elements, including Cd, Cr, Co, Cu, Pb, Mn, Hg, Ni, and Zn concentrations in mushrooms from Bangladesh. The mean concentrations (mg/kg) of As, Cd, Cr, Co, Cu, Pb, Mn, Hg, Ni, and Zn in mushrooms were 0.51, 0.38, 0.28, 0.01, 13.7, 0.31, 11.7, 0.12, 0.28, and 53.5, respectively. Based on the dietary intake of mushrooms, the weekly intakes of As, Cd, Cr, Co, Cu, Pb, Mn, Hg, Ni, and Zn from mushrooms for adults were 0.0042, 0.0030, 0.0024, 0.0001, 0.1125, 0.0019, 0.1116, 0.0011, 0.0023, and 0.4734 mg, respectively. Due to the low concentrations of As and other trace elements observed in mushrooms from Bangladesh, as well as relatively lower consumption of this food in people’s diet, it can be inferred that consumption of the species of mushrooms analysed will cause no toxicological risk.

Human health risk assessment of heavy metals in soils and commonly consumed food crops from quarry sites located at Isiagwu, Ebonyi State

Abstract In view of ensuring healthy agricultural foods for human consumption, this study assessed the human health risk implicated in selected heavy metals in some commonly consumed vegetables, tubers, nuts and fruits grown around the quarry sites at Ishiagu, Ebonyi State, Nigeria. Samples from agriculture area of Umudike, Abia State, Nigeria, constituted the control. The concentration of Mn, Zn, Fe, Cu, Cd, and Pb, were determined using atomic absorption spectrometry. The potential non-carcinogenic health risk for consumers which included Estimated Daily Intake (EDI) and Target Hazard Quotients (THQ) for Pb, Fe, Mn, Zn, Cd and Cu while carcinogenic health risk using Cancer Slope Factors (CSF) was established for Cd and Pb. Relative abundance of heavy metals across the locations and all samples was in the order Fe > Mn > Zn > Pb > Cu > Cd. There was statistical significant effect of quarrying activities on the concentration of the heavy metals (Fe, Mn, Zn, Pb, Cu, Cd) at p < 0.05 level. Based on the observed bioconcentration factors, cassava showed more hyperaccumulation potential compared to other samples. Pumpkin and bitter leaf also could be used in remediation owing to their high bioaccumulation index for Pb and Zn. THQ obtained for Mn and Pb were >1 indicating that the residents at the quarry site may be exposed to potential non-carcinogenic health risk due to Mn and Pb intoxication. With respect to US EPA prescriptions, average carcinogenic risk values obtained for Pb and Cd in this study indicated a lifetime (70 years) probability of contracting cancer suggesting that they be placed for further consideration as chemicals of concern with respect to the assessed locals.

Maximum cadmium limits establishment strategy based on the dietary exposure estimation: an example from Chinese populations and subgroups.

Dietary exposure to cadmium (Cd) in the Chinese population is currently a public health concern. China's national standard for maximum limits (MLs) of Cd in foods needs to be assessed. The objective of this research is to estimate the impacts of different Cd MLs intakes from selected foods and food groups and to provide scientific evidence for ML establishment. Food consumption data were taken from the Chinese National Diet and Nutrition Survey. Cd contamination data were obtained from the National Food Contamination Monitoring Program. A beta binomial normal (BBN) model was applied in the probabilistic assessment. Different possible ML scenarios for rice were selected to assess the impact of different MLs on Cd concentration and intake. More than 70% of children aged 2-6years and over 30% of the general population have a dietary daily Cd intake above provisional tolerable daily intake (PTMId). Cd intake changed greatly relative to baseline when different possible MLs were used, but the changes were not as large when compared among the different possible MLs. Cd exposure in China, especially for children, is a public health concern. It is recommended that the ML for rice be held at 0.2mg/kg.

Determination of mineral contents of wild Boletus edulis mushroom and its edible safety assessment

ABSTRACTThis study aimed to determine the contents of main mineral elements of wild Boletus edulis and to assess its edible safety, which may provide scientific evidence for the utilization of this species. Fourteen mineral contents (Ba, Ca, Cd, Co, Cr, Cu, Fe, Mg, Mn, Na, Ni, Sr, V and Zn) in the caps and stipes of B. edulis as well as the corresponding surface soils collected from nine different geographic regions in Yunnan Province, southwest China were determined. The analyses were performed using inductively coupled plasma atomic emission spectrometer (ICP-AES) after microwave digestion. Measurement data were analyzed using variance and Pearson correlation analysis. Edible safety was evaluated according to the provisionally tolerable weekly intake (PTWI) of heavy metals recommended by United Nations Food and Agriculture Organization and World Health Organization (FAO/WHO). Mineral contents were significantly different with the variance of collection areas. B. edulis showed relative abundant contents of Ca, Fe, Mg and Na, followed by Ba, Cr, Cu, Mn and Zn, and the elements with the lower content less were Cd, Co, Ni, Sr and V. The elements accumulation differed significantly in caps and stipes. Among them, Cd and Zn were bioconcentrated (BCF > 1) while others were bioexcluded (BCF < 1). The mineral contents in B. edulis and its surface soil were positively related, indicating that the elements accumulation level was related to soil background. In addition, from the perspective of food safety, if an adult (60 kg) eats 300 g fresh B. edulis per week, the intake of Cd in most of tested mushrooms were lower than PTWI value whereas the Cd intakes in some other samples were higher than this standard. The results indicated that the main mineral contents in B. edulis were significantly different with respect to geographical distribution, and the Cd intake in a few of regions was higher than the acceptable intakes with a potential risk.

Geographical variations of cadmium and arsenic concentrations and arsenic speciation in Chinese rice

Rapid industrialization in China in recent decades has resulted in soil contamination in some areas, raising the concern about food safety. Consumption of rice represents a major exposure route for the toxic elements cadmium (Cd) and arsenic (As). We collected 160 polished rice from local markets in 20 provinces in China and determined total Cd and As concentrations and As speciation. Total Cd concentration ranged from below the detection limit to 0.77 mg kg−1, with 10% of the samples exceeding the Chinese limit (0.2 mg kg−1). Rice Cd concentration showed a distinct geographical pattern, increasing from low levels in the north to high levels in the south of China. Median daily Cd intake from rice varied from 0.01 μg kg−1 body weight in the north to 0.61 μg kg−1 body weight in the south of China, representing between 1% and 73% of the tolerable daily intake (TDI) recommended by FAO/WHO. The highest median Cd intake from rice was in Hunan province with 2 times TDI. Total As concentration ranged from 0.011 to 0.186 mg kg−1, with inorganic As (iAs) and dimethylarsinic acid (DMAs) on average accounting for 69% and 31%, respectively. All samples were below the Chinese limit for iAs in rice (0.2 mg kg−1). There was no clear geographical pattern in rice total As concentration, but rice produced in northeastern China contained higher percentages of DMAs and lower percentages of iAs. This study highlights a high risk of Cd exposure from rice consumption for the population of southern China and suggested strategies for reducing Cd accumulation in rice crop.

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.

Increase of lifetime cadmium intake dose-dependently increased all cause of mortality in female inhabitants of the cadmium-polluted Jinzu River basin, Toyama, Japan

BackgroundExposure to cadmium (Cd) via food is supposed to affect life prognosis of inhabitants of Cd-polluted area in Japan. However, there have been few reports demonstrating a significant relationship between the amount of Cd intake and mortality. We aimed to investigate the relationship between mortality and individual lifetime Cd intake (LCd) in inhabitants of the polluted Jinzu River basin, Toyama, Japan. MethodsWe conducted a 26-year follow-up survey in 2407 inhabitants (1208 men and 1199 women) who participated in health examinations for screening of renal dysfunction from 1979 to 1984. The calculation of LCd in each inhabitant was based on the formula of Nogawa (Nogawa et al., 1989): (mean Cd concentration in rice of the present hamlet × 333.5 g/day + 34 μg/day) × 365 days/year × number of years of residence in the present hamlet + 50 μg/day × 365 days/year × number of years living in Cd non-polluted regions. In this formula, 333.5 g/day is the 1970 average daily intake of rice in this area, 34 µg/day is the Cd intake from foods other than rice in this area, and 50 μg/day is the average intake of Cd in non-polluted areas in Japan. Mortality risk ratios of LCd for all and specific causes were estimated after adjustments for age at baseline, smoking status, and history of hypertension using a Cox hazard model or Fine and Gray competing risks regression model. ResultsThe mortality risk ratios of LCd (+ 1 g) for all causes in women were significantly dose-dependently increased (risk ratio: 1.08). Relative risk of LCd for kidney and urinal tract disease, renal diseases, renal failure and toxic effects of cadmium were significantly higher in women. ConclusionsThe present study documents that individual LCd dose-dependently decreased life prognosis over long-term observation in women. LCd was significantly related to the increased mortality for renal disease and toxic effect of Cd in women. The result provides clear evidence that life prognosis was adversely affected by Cd-exposure, especially in women.

Dietary Cadmium Intake and Its Effects on Kidneys.

Cadmium (Cd) is a food-chain contaminant that has high rates of soil-to-plant transference. This phenomenon makes dietary Cd intake unavoidable. Although long-term Cd intake impacts many organ systems, the kidney has long been considered to be a critical target of its toxicity. This review addresses how measurements of Cd intake levels and its effects on kidneys have traditionally been made. These measurements underpin the derivation of our current toxicity threshold limit and tolerable intake levels for Cd. The metal transporters that mediate absorption of Cd in the gastrointestinal tract are summarized together with glomerular filtration of Cd and its sequestration by the kidneys. The contribution of age differences, gender, and smoking status to Cd accumulation in lungs, liver, and kidneys are highlighted. The basis for use of urinary Cd excretion to reflect body burden is discussed together with the use of urinary N-acetyl-β-d-glucosaminidase (NAG) and β2-microglobulin (β2-MG) levels to quantify its toxicity. The associations of Cd with the development of chronic kidney disease and hypertension, reduced weight gain, and zinc reabsorption are highlighted. In addition, the review addresses how urinary Cd threshold levels have been derived from human population data and their utility as a warning sign of impending kidney malfunction.

Heavy metal contamination status in seven fish species from reservoirs of Polonnaruwa district, Sri Lanka

Heavy metal contamination in aquatic ecosystems has become an emerging environmental issue. The stable physico-chemical properties of heavy metals could result in bioconcentration and bioaccumulation in different organs of freshwater fishes. The present study records the accumulation of Lead (Pb), Cadmium (Cd), Chromium (Cr), Copper (Cu) and Zinc (Zn) in the head, muscle and skin regions of seven fish species namely, Labeo rohita , Oreochromis mossambicus, Oreochromis niloticus, Etroplus suratensis , Heteropneustes fossilis , Oligolepsis acutipennis and Puntius dorsalis collected from Minnerya, Parakrama Samudraya and Kaudulla reservoirs in Polonnaruwa district, Sri Lanka. The results showed that both Pb and Cd accumulated in high concentrations in the head region compared to the skin and muscles of the fish samples. The highest amounts of Pb (22.44±5.48 mg/Kg) and Cd (4.98±0.86mg/Kg) were recorded from the head parts of the H. fossilis in Minneriya and O. niloticus in Kaudulla respectively, whereas the highest amount of Cr (30.87±4.51mg/Kg) was detected in head part of the O. acutipennis in Minneriya. The Cu concentration was the highest (2.92±0.001 mg/Kg) in head regions of H. fossilis from Minneriya. Zn was the most abundant heavy metal detected in the head, muscle and skin regions of fish in all three reservoirs. The highest amount of Zn (118.93±10.55mg/Kg) was detected in the head part of O . acutipennis from Minneriya. The Pb, Cd, Cr, Cu and Zn concentrations detected in the head part of popular edible freshwater species, O. mossambicus, O. niloticus and E. suratensis were higher than the provisional tolerable weekly intake (PTWI) of Pb (0.025 mg/Kg), Cd (0.007 mg/Kg), Cr (0.1 mg/Kg), Cu (3.5 mg/Kg) and Zn (7 mg/Kg) specified by the FAO/WHO. Therefore, long-term consumption of these fish species especially the head parts may lead to accumulation of these heavy metals in tissues and lead to chronic diseases which may risk the health of consumers especially in the north-central province of Sri Lanka.

Cadmium treatment induces echinocytosis, DNA damage, inflammation, and apoptosis in cardiac tissue of albino Wistar rats

Cadmium (Cd), a potent carcinogen present in almost all foods, poses a major health risk to humans. Major routes of exposure to Cd for humans are occupation, diet, and tobacco use. Cd elicits various deleterious effects on cellular molecules mainly by causing oxidant-antioxidant imbalance. Cd has been implicated in the pathogenesis of many cancers, Itai-itai disease, diabetic nephropathy, hypertension, peripheral artery disease, and myocardial infarction. This study was designed to investigate the effects of Cd intake on erythrocytes and cardiac tissue in male albino Wistar rats. We treated male albino Wistar rats with cadmium chloride (CdCl2) by intra-gastric administration for 30 days and examined Cd burden and changes in blood constituents and antioxidant status of blood and cardiac tissue. We also studied the structural alterations in the erthrocytes, elemental changes and Cd burden in cardiac tissue using scanning electron microscope (SEM/EDX). Inflammation and apoptosis were analysed in the cardiac tissue by polymerase chain reaction (PCR), western blotting, and DNA fragmentation assay. Cd treatment resulted in echinocytosis of erythrocytes and distorted myofibrils arrangement, vacuolization and congestion in the vessels. Cd administration has also induced inflammation and apoptosis in the cardiac tissue. At molecular level, Cd administration caused oxidative damage to DNA, lipids, and proteins and diminished the activities of various antioxidants. The present study provides a compelling evidence of Cd-induced imbalance in oxidant-antioxidant system with damage to erythrocytes and cardiac tissue that may contribute to various cardiac diseases.

Impact of irrigation with wastewater on accumulation of heavy metals in soil and crops in the region of Marrakech in Morocco

Abstract Actually, the accumulation of heavy metals by crops irrigated by wastewater has considered a serious environmental problem in many countries such as Morocco, where the wastewater irrigation has become a widespread practice. In this study, we were interested in highly toxic metals such as zinc (Zn), copper (Cu), lead (Pb) and cadmium (Cd) in water, agricultural soils and crops and their possible risk on human health in the region of Marrakech. The physicochemical parameters pH, electrical conductivity, organic carbon and organic matter, were determined for the samples. Irrigated water, soil and vegetable samples for Zn, Cu, Pb and Cd concentrations and transfer factor from soils to plants (TF) were analyzed, daily intake of metals (DIM) and health risk index (HRI) were calculated. The irrigated soil was contaminated with Zn (112.71 mg/kg), Cu (17.70 mg/kg), Pb (57.36 mg/kg) and Cd (11.22 mg/kg). The trend of heavy-metal concentrations in all samples was Zn > Pb > Cu > Cd. The daily intake (DIM) for Cd and Pb exceeded the permissible limits. The Health Risk Index (HRI) varied from 0.054–0.174 for Zn, 0.031–0.242 for Cu, 2.407–7.973 for Pb and 0–5.059 for Cd. The HRI was >1 for Cd and Pb indicating a potential health risk. Our results revealed high risks indexes, heavy metal contaminated food crops in our study area, and consequently, a great health risk to the local human and animal populations. Thus, preventive measures must be taken to reduce heavy metal pollution of irrigation water and soils to protect both, human and animal health in Marrakech and Morocco.

Cadmium uptake, accumulation, and remobilization in iron plaque and rice tissues at different growth stages

Rice consumption is considered the main source of human dietary Cd intake in Southeast Asia. This study aimed to investigate Cd uptake, accumulation, and remobilization in iron plaque and rice (Oryza sativa L. cv. ‘Xiangwanxian 12′) tissues at different growth stages. A pot experiment was performed in two Cd-contaminated paddy soils. Cd concentrations in iron plaque and rice tissues at five different growth stages (tillering, booting, milky, dough, and maturing) were measured. Cd concentrations in iron plaque and rice tissues (roots, stems, leaves, spikelet, husks, and brown rice) varied with growth stage. Cd accumulation in rice plants increased with extending growth in both soils, reaching 15.3 and 35.4μg/pot, respectively, at the maturing stage. The amounts of Cd in brown rice increased from the milky to maturing stages, with the greatest percentage uptake during the maturing stage. Cd amount in iron plaque significantly affected the uptake and accumulation of Cd in roots and aerial parts of rice plants. Accumulated Cd in leaves was remobilized and transported during the booting to maturing stages, and the contributions of Cd transportation from leaves to brown rice were 30.0% and 22.5% in the two soils, respectively. A large amount of Cd accumulated in brown rice during the maturing stage. The transportation of remobilized Cd from leaves was also important for the accumulation of Cd in brown rice.

A Limited Survey of Metal Content in Blue Jack Mackerel (Trachurus picturatus) Obtained from Markets in the Canary Islands

The levels of 20 metals (aluminum, boron, barium, calcium, cadmium, cobalt, chromium, copper, iron, potassium, lithium, magnesium, manganese, molybdenum, sodium, nickel, lead, strontium, vanadium, and zinc) were analyzed in muscle and liver tissue of Trachurus picturatus marketed in the Canary Islands (Spain) by using inductively coupled plasma optical emission spectrometry. In the liver samples, the mean concentrations in milligrams per kilogram wet weight (wt) of Al (14.7), B (0.99), Ba (1.64), Ca (314), Cd (2.52), Co (0.15), Cu (4.07), Fe (106), Li (3.89), Mn (0.85), Mo (0.16), Na (1510), Ni (0.51), Pb (0.36), Sr (3.54), V (0.78), and Zn (23.13) were higher than those detected in the muscle samples in milligrams per killogram wet wt, which were as follows: Al (8.76), B (0.07), Ba (0.30), Ca (210), Cd (0.01), Co (0.01), Cu (1.51 ), Fe (7.33), Li (1.08), Mn (0.12), Mo (0.01), Na (697), Ni (0.11), Pb (0.04), Sr (1.45), V (0.01), and Zn (4.69). The mean concentrations of Cr, K, and Mg (0.14, 1,904, and 243 mg/kg wet wt, respectively) were higher in muscle than in liver (0.05, 1,333 and 236 mg/kg wet wt, respectively). The mean concentrations of Cd and Pb (0.01 and 0.04 mg/kg wet wt) in muscle did not exceed the maximum limits established by a European Commission regulation (0.1 mg of Cd/kg and 0.3 mg of Pb/kg, respectively). Considering a mean daily consumption of fish muscle for the adult population of 31.9 g/day published in the report on food consumption by the Spanish Ministry of Agriculture and Fisheries, Food and Environment, Mg made the highest contributions to the intake (2.58% for adult women of 60 kg and 2.22% for men of 70 kg), and the estimated intakes of Al (0.35 to 0.46 mg/day), Cd (0.55 to 0.74 mg/day) and Pb (1.66 to 5.53 mg/day) were below the respective established tolerable intakes. In conclusion, the results of this study show that the consumption of muscle from this benthopelagic species can be considered safe in terms of maximum legal limits, while consumption of liver is discouraged as a major source of exposure to toxic metals, such as Al, Cd, and Pb.

Effects of the addition and aging of humic acid-based amendments on the solubility of Cd in soil solution and its accumulation in rice

Humic substances can reduce mobility and bio-accessibility of Cd in soil and therefore inhibit its uptake by rice, which is a major source of human Cd intake. Yet, the effects of aging humic substances are not fully understood. A rice pot experiment was conducted to evaluate the effects of humic acid-based amendments on the mobility of Cd in soil solution and its uptake by rice when amendments were freshly added or aged for 130 d. The results showed that the aged and the unaged amendments generally decreased Cd concentration in soil solution, but the effect declined with time. Unaged HA-K (humic-potassium) reduced Cd concentration by 88% for the first sampling, but this dropped to 46% for the last sampling, compared to that of the control. All amendments, whether aged or not, reduced the content of Cd in rice seedlings, as well as in mature plants. Aged and unaged woody peat reduced the Cd content in seedlings by 79% and in grains by 70%, respectively. Aging of amendments caused lower pH and higher Cd concentration in the soil solution for all amendments and accordingly, the Cd content in rice seedlings or each part of mature plants in the aged group was higher than that of the unaged group. The applied amendments might reduce the solubility of Cd through the alteration in soil pH, and thus inhibit the uptake of Cd by rice, but the effects diminished with aging.

Assessing the Bioaccessibilities of Some Elements in Fruit Based Complementary Baby Foods

In this study, total concentrations and bioaccessibility of some essential and toxic elements (As, Cd, Cr, Cu, Fe, Mg, Mn, Ni, Pb and Zn) were determined in commercial fruit purees intended for baby consumption as complementary foods. Enzymatic in vitro digestions were performed to simulate the stomach and the intestine conditions. A five-level, three factor central composite design, was applied to optimize the open-wet digestion methodology as well as enzyme amounts used in vitro methods to achieve maximum elemental levels. Rice flour and baby food composite certified reference materials analysis were applied to optimize the digestion parameters and evaluate the accuracy of the optimized method. Water fractions of samples were analyzed and evaluated in terms of their suitability for risk assessment studies by inductively coupled plasma mass spectrometry. Recommended dietary allowance level of 1.3% for Zn, adequate intake levels of 15.3%, 0.04%, 4.4% and 68% for Cu, Mg, Mn and Cr, respectively were achieved as well as 20%, 6% level and 2% tolerable intakes of Cd, Ni and As, respectively. Thus, contribution of the consumption of one jar of fruit based complementary baby food to diet of infants aged up to 12 months were assessed.

Trace metal(loid)s exposure through soil–tobacco–human pathway: Availability in metal-contaminated agricultural soils, transfer models and health risk assessment

High concentrations of trace metal(loid)s in cigarette tobacco are likely the result of soil contamination and seriously threaten the health of smokers and non-smokers. This study aims to improve soil protection guidelines by carefully examining metal(loid)s uptake by tobacco leaves and human exposure to metal(loid)s through the soil–tobacco–smoker pathway. Soil and tobacco tests and health risk assessment were performed. Soil results indicated that the exchangeable fractions, greatly influenced by soil pH in historically contaminated (HC) agricultural soils were small but the geochemically reactive fractions were very large, representing a great potential of phytoavailability. Greenhouse experiments for tobacco (Nicotiana tabacum L.) grown on both HC and artificially metal-spiked (AS) soils indicated that tobacco leaves accumulated high concentrations of Zn, followed by Pb, Cu, Cd, Cr, Ni and As. Exposure model indicates that consuming the contaminated tobacco can result in an unacceptable inhalation intake of Zn (138mgkg−1year−1), As (0.64), Cd (4.9), Pb (5.9) and Cu (8.9) for women in particular. Plant-available fractions of As, Cd, Pb, Zn, Cu and Cr in soils explained 85–100% of the variation for tobacco metal(loid)s. Reliable soil-tobacco transfer models were derived and validated with field data. In the present study, contaminated soils are unsafe for growing tobacco identified by the inverse use of empirical models based on regulatory limits estimated for tobacco metal(loid)s. This work provides a basis in a regulatory context of tobacco metal(loid)s exposure.

Health Risk Contamination of Heavy Metals in Yolk and Albumen of Duck Eggs Collected in Central and Western Thailand.

Two hundred duck egg samples were collected from 20 farms in Central and Western Thailand. The levels of Zn, Co, Mn, Fe, and Cr in yolks were found significantly higher than in albumen, whereas the levels of Cd and Cu contaminations in egg albumen were significantly higher than in yolks. The mean level of Pb contamination in whole eggs was 4.06 ± 2.70mgkg-1 dry weight. This level was higher than the Thai agricultural standard no. 6703-2005 for duck eggs set at 0.1ppm for the magnitude of 40.6 times. In addition, 98% (196/200) of duck egg samples had Pb levels higher than the standard limit. However, the calculation of daily intakes of Pb, Cd, and Cu contamination in the current study of duck eggs shows that these metals were lower than the World Health Organization and the Food and Agriculture Organization provisional tolerated daily intake. These levels may, however, present a health risk resulting from a long-term exposure. It can be concluded that consumers may be at risk of Pb, Cd, and Cu contamination if they consume contaminated duck eggs. In addition, long-term monitoring of the health risks of heavy metals contamination should be conducted concerning the duck egg production system in Thailand.

Metals in Diplodus sargus cadenati and Sparisoma cretense-a risk assessment for consumers.

The increases in urbanization, demography and industrial activity, along with growing human needs which exploit the resources of the planet, have exponentially exacerbated pollution. In particular, the discharge of heavy metals into the marine ecosystem is a problem of global magnitude, as this may damage the diversity of marine species and ecosystems because of their toxicity, long persistence and bioaccumulation. Consequently, it is necessary to carry out an assessment of the risk of human exposure from the consumption of marine species potentially exposed to this type of pollutants. In the present study, the levels of toxic heavy metals (Cd, Pb and Al) as well as trace and essential metals (B, Ba, Co, Cu, Cr, Fe, Li, Mn, Mo, Ni, Sr, V and Zn) and macronutrients (Ca, K, Mg, Na) have been quantified in two species of fish for human consumption. In order to do this, a total of 80 muscle samples and 80 liver samples, belonging to two species of osteichthyes (bony fish), Diplodus sargus cadenati and Sparisoma cretense, were analyzed. The specimens studied were captured on the north coast of Gran Canaria (Canary Islands) using recreational fishing techniques. As they caught from the shore, the data obtained respond to the need to assess the toxic levels in two representative species of artisanal and recreational fishing in the area. The risk assessment indicated that these two fish species are safe for the average consumer; however, if the livers are frequently consumed, there may be potential risks because they exceed the Admissible Daily Intakes for Pb and Cd.

Knockout of OsNramp5 using the CRISPR/Cas9 system produces low Cd-accumulating indica rice without compromising yield

Rice grain with excessive cadmium (Cd) is a major source of dietary Cd intake and a serious threat to health for people who consume rice as a staple food. The development of elite rice cultivars with consistently low Cd content is challenging for conventional breeding approaches, and new strategies urgently need to be developed. Here, we report the development of new indica rice lines with low Cd accumulation and no transgenes by knocking out the metal transporter gene OsNramp5 using CRISPR/Cas9 system. Hydroponic culture showed that Cd concentrations in shoots and roots of osnramp5 mutants were dramatically decreased, resulting in rescue of impaired growth in high Cd condition. Cd-contaminated paddy field trials demonstrated that Cd concentration in osnramp5 grains was consistently less than 0.05 mg/kg, in contrast to high Cd concentrations from 0.33 mg/kg to 2.90 mg/kg in grains of Huazhan (the wild-type indica rice). In particular, the plant yield was not significantly affected in osnramp5 mutants. Furthermore, we developed promising hybrid rice lines with extremely low Cd content in grains. Our work supplies a practical approach to developing Cd pollution-safe indica rice cultivars that minimizes Cd contamination risk in grains.