Differences In Cd Concentrations Research Articles

Measurements of cadmium levels in relation to tobacco dependence and as a function of cytisine administration

Cigarette smoking delivers a number of heavy metals, including cadmium (Cd), into the body. Bioaccumulation may result in an increase in pathological consequences over time. The assessment of changes in serum Cd concentrations during the treatment of cigarette dependence with cytisine was performed for the first time. Parameters assessing smoking habits, strength of addiction, and effectiveness of therapy were analyzed. Cd was determined before, during, and after the end of treatment. The serum Cd levels were significantly higher in the smokers than in the nonsmokers. Significant differences in Cd concentrations between sampling times in smokers were observed. Individuals who stopped smoking had significantly lower Cd concentrations compared to baseline. A significant positive correlation between the serum Cd before treatment and smoking urges was also obtained. Additionally, salivary Cd determinations were performed before treatment to evaluate the use of this method to assess cigarette addiction. Our findings indicate that Cd can be used as a biomarker of smoking addiction, and provide an alternative assessment of tobacco smoke exposure to other methods. The results provide new knowledge related to Cd concentrations in human body fluids and may play a role in monitoring and assessing the efficacy of cytisine for smoking cessation.

Nitrate-induced AHb1 expression aggravates Cd toxicity in plants

Cadmium (Cd) causes severe toxicity in plants. However, the molecular mechanisms underlying plant resistance to Cd in relation to nitrogen (N) supply remain unclear. The non-symbiotic hemoglobin gene Hb1 plays an important role in scavenging nitric oxide (NO) in plants. In this study, there was no differential effect of Cd on the biomass of wild-type (WT) and AHb1-overexpressing (H7) plants when NH4+-N was used as a nitrogen source. However, under NO3−-N conditions, Cd exerted less biomass stress on AHb1-silenced (L3) plants and more stress on H7 plants than on WT plants. The Cd tolerance index followed the order: L3 > WT > H7. However, there was no difference in Cd concentrations in the roots or shoots of the WT, L3, and H7 plants, indicating that differences in AHb1 expression were unrelated to Cd uptake. Further investigation showed that Cd exposure enhanced H2O2 accumulation and aggravated oxidative damage in H7 plants. The application of an NO donor effectively reversed growth inhibition, H2O2 burst, and oxidative stress induced by Cd in H7 plants. Thus, we suggest that NO3−-induced AHb1 expression suppresses Cd-induced NO production in plants, increasing the ROS burst and exacerbating Cd toxicity.

Cutting height of main crop has profound effects on cadmium but not arsenic concentration of ratoon crop in rice

ContextRice contamination with heavy metals seriously threatens human health. Ratoon rice plays a vital role in food security in China, whereas limited information is available on its heavy metal accumulation. Research questionCutting height of main crop is an important crop management practice affecting the growth and yield of ratoon crop (RC), whereas its effects on heavy metals accumulation in RC is still unknown. MethodsField experiments were conducted in 2019 and 2020 to investigate the effects of different cutting heights (high: 45 cm, medium: 15 or 25 cm, and low: 5 cm) on cadmium (Cd) and arsenic (As) concentrations in RC. ResultsCutting height had small and inconsistent effects on As concentration in RC. However, grain Cd concentration of RC in high and medium cutting heights were significantly reduced by 87.5 % and 79.8 % than that in low cutting height, respectively. Similarly, Cd concentrations of stubble and straw at maturity were also significantly lower in high and medium cutting heights than in low cutting height. Regenerated tillers in the low node position were responsible for the differences in Cd concentration among the cutting heights. ConclusionThe increase in cutting height of main crop significantly decreased Cd concentration but has small effects on As concentration in RC. ImplicationsOur results suggest that high cutting height during the harvest of main crop should be considered when rice ratooning is practiced in the environment with Cd-contaminated soil.

Phytoremediation with kenaf (Hibiscus cannabinus L.) for cadmium-contaminated paddy soil in southern China: translocation, uptake, and assessment of cultivars.

Kenaf (Hibiscus cannabinus L.) is suitable for growing in heavy metal-polluted soil for non-food purposes and can be used as a potential crop to remediate heavy metal-contaminated soil. The main objective of this study was to investigate kenaf phytoextraction of cadmium (Cd), including uptake, translocation, and accumulation differences in tissues among kenaf cultivars. A field experiment was conducted in a Cd contaminated paddy field in southern China area with 13 kenaf cultivars in 2015 and 2016. Agronomic performance, Cd concentrations in plant tissues (root, xylem, and phloem), and biomass of different tissues of each cultivar were measured and evaluated. Significant differences in Cd concentrations and accumulation among tissues and cultivars were observed. The phloem had the highest Cd accumulation and transfer capability compared with the roots and xylem. Approximately 35 ~ 65g of Cd could be taken up by the aerial parts of different kenaf cultivars within every hectare of soil. The percentage of Cd uptake by the phloem ranged from 47 to 61% and by the xylem ranged from 38 to 53%. By evaluating the agronomic traits and Cd bioaccumulation capacity, Fuhong 952, Fuhong 992, and Fuhong R1 were regarded as Cd accumulators for the phytoremediation of Cd-contaminated soil. Our study clearly demonstrated that a significant level of Cd in the soil was taken up through the phytoremediation with kenaf. In addition, harmless utilization of kenaf planting in Cd-contaminated paddy soil was discussed.

Forage crops and cadmium: How changing farming systems might impact cadmium accumulation in animals

Production advantages, environmental benefits and increasing parasite resistance are changing the composition of New Zealand pastures. Traditional ryegrass/clover pasture mixes are being replaced by forage herb crops such as lucerne, chicory and plantain that accumulate a higher concentration of contaminants such as cadmium (Cd). To explore the relationship between Cd in forage crops and the Cd concentration accumulated by animals, four-month-old lambs at four farms across the central North Island of New Zealand were grazed on different forage crops (ryegrass, chicory, lucerne and plantain) between weaning and slaughter. Soil and pasture samples, and sequential liver biopsies, were collected and analysed for total Cd. There were significant differences in Cd concentration between the forage crops (chicory > plantain > lucerne > ryegrass) and this ordering was repeated for Cd in liver. There was no exceedance of maximum limits (ML) for Cd in offal set by the EU and NZ/Australia food safety standards authorities for animals of this study, although the highest concentration of Cd in chicory (0.85 mg/kg DW) was considerably lower than has been recorded elsewhere in New Zealand (4.5 mg/kg DW). Provisional Soil Management Values (SMVs) were developed to explore compliance of liver with EU food standards as a function of grazing chicory. For a soil pH of 5, exceedance might occur at a soil cadmium concentration of 0.34 mg/kg. This concentration falls within Tier 0 of the New Zealand Tiered Fertiliser Management System which seeks to ensure soil Cd remains within acceptable limits over the next 100 years and beyond. Increased Cd uptake by fodder crops and its management in these Tier 0 pastoral soils is therefore an emerging issue for pastoral agriculture. The risk of ML exceedance for animals grazing forage crops such as chicory on low Cd soils should be further considered to ensure uninterrupted access to export markets.

Root Morphology and Anatomy Affect Cadmium Translocation and Accumulation in Rice

Paddy fields contaminated with cadmium (Cd) present decreased grain yield and produce Cd-contaminated grains. Screening for low-Cd-accumulating cultivars is a useful method to reduce the amount of Cd in the grains. The present study aimed to examine the roles of the root morphology and anatomy in Cd translocation and accumulation in rice plants. Twenty-two rice cultivars were used in the first experiment, after which two cultivars [Zixiangnuo (ZXN) and Jinyou T36 (JYT36)] were selected and used in subsequent experiments under hydroponic conditions. The results showed that there were significant differences in Cd concentrations in the shoots (ranging from 4 to 100mg/kg) and the Cd translocation rates (shoot/root) (from 7% to 102%) among the 22 cultivars, and the shoot Cd concentration was significantly correlated with the Cd translocation rate of the 22 cultivars under 0.1mg/L Cd treatment. Compared with cultivar ZXN, JYT36 had greater root Cd uptake and accumulation but lower shoot Cd accumulation and Cd translocation rate. The number of root tips per surface area of cultivar ZXN was greater than that of JYT36, while the average root diameter was lower than that of JYT36. Compared with ZXN, JYT36 had stronger apoplastic barriers, and the Casparian bands and suberin lamellae in the root endodermis and exodermis were closer to the root apex in both the control and Cd treatments, especially for suberin lamellae in the root exodermis with Cd treatments, with a difference of 25mm. The results also showed that, compared with ZXN, JYT36 had greater percentages of Cd bound in cell walls and intracellular Cd but lower Cd concentrations in the apoplastic fluid under the Cd treatment. The results suggested that Cd translocation, rather than root Cd uptake, is a key process that determines Cd accumulation in the rice shoots. The root morphological and anatomical characteristics evidently affect Cd accumulation in the shoots by inhibiting Cd translocation, especially via the apoplastic pathway. It was possible to pre-screen low-Cd-accumulating rice cultivars on the basis of their root morphology, anatomical characteristics and Cd translocation rate at the seedling stage.

Identification of a plant endophytic growth-promoting bacteria capable of inhibiting cadmium uptake in rice.

The study aims to identify a novel plant growth-promoting bacteria (PGPB), which contributes to promoting growth and reducing cadmium (Cd) concentration in rice under Cd-contaminated conditions. Nine bacterial strains were isolated from plants grown in Cd-contaminated soil. These bacteria were tolerant to 1000μmol/L CdCl2 , capable of producing indole-3-acetic acid, fixing nitrogen and solubilizing phosphate. The result of hydroponic experiment showed that under the control and Cd stress conditions, the dry weight of the Tm02-inoculated rice seedlings increased significantly. Furthermore, under Cd stress, the concentration of Cd in the shoot of the Tm02-inoculated seedlings decreased significantly, while there was no significant difference in Cd concentration between treatment with other eight strains and noninoculated seedlings. The same results were observed in the pot experiment as well, where there was a significantly reduced Cd concentration in rice grains of the Tm02-inoculated rice plants. Tm02 was classified as Pantoea agglomerans through 16S rDNA sequencing. A novel PGPB strain Tm02 was identified and confirmed that it has the function of promoting rice growth and reducing Cd concentration in rice grain under Cd-contaminated conditions. This strain has the potential to improve rice yield in Cd-contaminated paddy fields. This study provides a new example of using PGPB to improve the tolerance of rice to Cd pollution.

Selection for low-cadmium cultivars and cadmium subcellular distribution comparison between two selected cultivars of eggplant (Solanum melongena L.).

Excessive accumulation of cadmium (Cd) in vegetables poses a serious threat to human health; therefore, it is urgent to screen and cultivate vegetable cultivars with low Cd accumulation in the edible parts. Eggplant has a high tendency for Cd accumulation, but research on its low Cd accumulation cultivars is still rare. In this study, to screen low-Cd cultivars, 30 eggplant cultivars were screened using soils containing 0.22 mg/kg, 2.9 mg/kg (low-Cd), and 4.7 mg/kg of Cd (high-Cd). MYCQ and ZGQ were confirmed as low-Cd cultivars, BXGZ and WCCQ were confirmed as high-Cd cultivars, and a 2.52-3.88-fold difference in Cd concentration was observed in their fruits. The subcellular distribution revealed that the root cell wall and vacuole Cd concentrations of a typical low-Cd cultivar (MYCQ) were significantly higher than those of a typical high-Cd cultivar (BXGZ); however, the Cd concentrations in the cell wall and vacuole in fruits, leaves, and stems were significantly lower in MYCQ than in BXGZ. These results indicated that the low-Cd cultivars of eggplant could lessen Cd toxicity through the elevated Cd retention and sequestration levels of root cell walls and vacuoles, thus reducing Cd transport from roots to aboveground tissues, leading to low Cd accumulation. The findings of this study can provide a physiological and biochemical foundation for the screening and breeding of low-Cd cultivars of fruit vegetables and demonstrates that the application of low-Cd cultivars is necessary for food safety in humans.

Incidence and Public Health Risk Assessment of Toxic Metal Residues (cadmium and lead) in Liver and Kidney of Ovine and Bovine from Algeria

This study intended to establish if Cd and Pb in the livers and kidneys of bovine and ovine slaughtered in the study area exceeded to concentrations maximum limit proposed by the European Commission (EC) 2006. After digestion of samples, Cadmium and lead concentrations were determined by Graphite Furnace Atomic Absorption Spectrophotometry (GFAAS). The results of our study have shown that lead and cadmium concentrations depend on age and species. The average fresh weight levels of liver and kidneys of bovine animals were about (0.319 mg/kg and 0.337mg/kg) for Cd and (0,502mg/kg and 0.497mg kg) for Pb, while in ovine, mean concentrations in the liver and kidneys were (0,241mg/kg and 0.232 mg/kg) for Cd and (0.259 mg/kg and 0.265 mg/kg) for Pb. Concentrations above the maximum limit proposed by the EC 2006 for Pb and Cd have been detected in some liver and kidney samples from bovine older than 4 years and in ovine over 1 year old .Statistical analysis revealed a very significant (P<0.01) difference in Cd concentrations in the liver and kidneys between age groups and species.

Cadmium accumulation, translocation, and assessment of eighteen Linum usitatissimum L. cultivars growing in heavy metal contaminated soil

Flax (Linum usitatissimum L.) is suitable for growing in heavy metal polluted soil for non-food purposes and can be used as potential crops for cleaning the soil from heavy metals. The main objective of this study was to investigate flax/linseed phytoextraction of cadmium (Cd), including uptake, translocation, and accumulation differences in organs among flax/linseed cultivars. A field experiment was carried out in Cd contaminated field of Chinese southern area with nine flax, one dual-purpose, and eight linseed cultivars. Cd concentrations in plant organs (root, xylem, phloem, and capsule) and biomass of different organs of each cultivar were measured and evaluated. Significant differences in Cd concentration and accumulation among organs were observed. The most Cd was accumulated by phloem, which was 2 ∼ 4 times more than other organs, followed by roots, xylems and capsules played a comparably smaller role. The uptake of Cd by flax/linseed from per hectare was calculated and had highly significant positive correlation with biomass. Phloem accumulated 45 ∼ 55% of total Cd from the soil by the plant. Among testing 18 flax/linseed cultivars, one flax cultivar (Zhongya 1), and two linseed cultivars (Y2I329 and Y2I330), which extracted more than 60 g ha−1, can be considered as Cd accumulators for phytoremediation of Cd contaminated soil.

Cadmium accumulation and allocation in different cacao cultivars

Cadmium (Cd) is a biologically non-essential heavy metal that can cause toxic effects in plants, animals and humans already at low concentrations compared to other metals. After Cd concentrations in cacao beans of various provenances, particularly from Latin America, were found to exceed the new regulations enforced by the European Union in 2019, there is an urgent need to find measures to lower Cd accumulation in cacao beans to acceptable values. In this research, the long-term cacao cultivar trial CEDEC-JAS in northern Honduras was used to investigate differences between 11 cultivars in Cd uptake and translocation. Sampling of various plant parts, including rootstocks, scions, leaves and beans, from three replicate trees per cultivar and the soil around each tree was conducted at this site. Results indicate that concentrations of available soil Cd were more closely correlated with Cd concentrations of the rootstocks (R2 = 0.56), scions (R2 = 0.59) and leaves (R2 = 0.46) than with bean Cd concentrations (R2 = 0.26). In addition, Cd concentrations of rootstocks, scions and leaves showed close relationships to available soil Cd concentrations, with no significant differences between the cultivars. In contrast, bean Cd concentrations showed only weak correlations to available soil Cd and Cd concentrations in the vegetative plant parts, but significant variation among cultivars. Three cultivars, which were analysed in more detail, showed significant differences in Cd concentrations of mature beans, but not of immature beans. These results suggest that cultivar-related differences in bean Cd concentrations primarily result from differences in Cd loading during bean maturation, possibly due to cultivar-specific differences in the xylem-to-phloem transfer of Cd. The results show that selection of cultivars with low Cd transfer from vegetative parts into the beans has high potential to keep Cd accumulation in cacao beans at levels that are safe for consumption.

Cadmium uptake by onions, lettuce and spinach in New Zealand: Implications for management to meet regulatory limits

Paired soil and plant samples collected from the main commercial growing areas for onions (Allium cepa), lettuce (Lactuca sativa) and spinach (Spinacia olearacea) in New Zealand were used to assess the influence of plant and soil factors on cadmium (Cd) uptake in these crops. Differences in Cd concentration between eight lettuce sub-types were not consistent across sites, nor were differences in Cd concentrations in three crisphead cultivars assessed at two sites. Similarly, differences in Cd concentrations between four onion cultivars were inconsistent across sites. Mean lettuce Cd concentrations in eight lettuce varieties (range 0.005–0.034 mg∙kg−1 (fresh weight, FW) were markedly lower than those in baby leaf and bunching spinach, (range 0.005–0.19 mg∙kg−1 FW). Significant regional variation was observed in Cd concentrations in one onion cultivar (mean range 0.007–0.05 mg∙kg−1 FW). Soil Cd concentration, pH and region were statistically significant predictors of onion Cd concentration, explaining low (38% for soil Cd and pH) to moderate (50% for all three parameters) percentage of the variation. Soil Cd concentration and exchangeable magnesium or total carbon were statistically significant predictors of Cd concentration in baby leaf and bunching spinach, respectively, explaining a moderate percentage (49% and 42%) of the variation in Cd concentration. Increasing pH and soil carbon may assist in minimising Cd uptake in onion and bunching spinach, respectively. The low to moderate proportion of explained variation is partly attributable to the narrow range in some measured soil properties and indicates factors other than those assessed are influencing plant uptake. This highlights a challenge in using these relationships to develop risk-based soil guideline values to support compliance with food standards. Similarly, the inconsistency in Cd concentrations in different cultivars across sites highlights the need for multi-site assessments to confirm the low Cd accumulation status of different cultivars.

Chemical imaging and assessment of cadmium distribution in the human body.

The scientific interest in cadmium (Cd) as a human health damaging agent has significantly increased over the past decades. However, particularly the histological distribution of Cd in human tissues is still scarcely defined. Using inductively coupled plasma-mass spectrometry (ICP-MS), we determined the concentration of Cd in 40 different human tissues of four body donors and provided spatial information by elemental imaging on the microscopic distribution of Cd in 8 selected tissues by laser ablation (LA)-ICP-MS. ICP-MS results show that Cd concentrations differ by a factor of 20 000 between different tissues. Apart from the well know deposits in kidney, bone, and liver, our study provides evidence that muscle and adipose tissue are underestimated Cd pools. For the first time, we present spatially resolved Cd distributions in a broad panel of human soft tissues. The defined histological structures are mirrored by sharp cut differences in Cd concentrations between neighboring tissue types, particularly in the rectum, testis, and kidneys. The spatial resolution of the Cd distribution at microscopic level visualized intratissue hot spots of Cd accumulation and is suggested as a powerful tool to elucidate metal based toxicity at histological level.

Cadmium in pork and poultry liver in southern Poland

Samples of pork and poultry livers (ten samples of each type, purchased in southern Poland) were analyzed in order to determine the cadmium concentration. Wet digestion of the samples was carried out and the concentration of cadmium was measured by means of graphite-furnace atomic absorption spectrometry (GF-AAS). The mean values for pork and poultry livers were 79.3 µg/kg and 165.3 µg/kg, respectively. In one sample of poultry liver the Cd concentration was 1043 µg/kg, which is much more than the legal limit for the European Union (500 µg/kg). Statistical analysis showed that there was no significant difference in Cd concentration between the two groups of the samples, unless the highest result (1043 µg/kg) was considered an outlier.

Cadmium toxicity degree on tomato development is associated with disbalances in B and Mn status at early stages of plant exposure.

Cadmium (Cd) toxicity is frequently coupled to its accumulation in plants, but not always the highest Cd concentration triggers the worst damages, indicating that additional events influence the magnitude of Cd side-effects. We investigated the early mechanisms behind the differential Cd-induced impacts on plant development of four tomato accessions with contrasting tolerance to Cd toxicity. At organ level, the highest Cd concentration was not associated with the largest biomass losses. In leaves, changes in superoxide dismutase and catalase activities were not related to differences in Cd concentration, which was unable to provoke H2O2 overproduction on the sixth day of plant exposure to this metal. Further investigation in the mineral profile revealed that magnitude of Cd toxicity depends probably on synergic effects from increased B status, in addition to the own Cd accumulation. Furthermore, disbalances in Mn status (i.e., excess in leaves and deficiency in roots) may enhance Cd toxicity degree. According to data, however, the low magnesium (Mg) status can be linked to tomato tolerance against Cd toxicity. In conclusion, the tomato tolerance degree under short-Cd exposure depends on actively, finely regulation of mineral homeostasis that results in different development of plant organs. The better understanding on the mode of action of Cd toxicity in plants can help in the establishment of strategies to mitigate its impacts on crop yield.

Cadmium accumulation and subcellular distribution in populations of Hylotelephium spectabile (Boreau) H. Ohba.

A pot experiment was conducted among six populations of Hylotelephium spectabile (Boreau) H. Ohba: four from Jiangsu province, one from Shandong province, and one from Shanxi province, China, to investigate the variation of Cd accumulation and subcellular distribution of this species (a newly reported Cd high accumulator). Under five different real Cd-contaminated soils (Cd: 0.93-97.97mg/kg), results showed considerable differences in Cd concentration in (a) leaf (1.09-50.7mg/kg), (b) stem (0.61-13.0mg/kg), and (c) root (1.55-24.5mg/kg) among the populations. Analysis of subcellular Cd distribution indicated that Cd accumulated in the leaves of H. spectabile was mainly in the cellular debris (44.1 to 53.5%), followed by heat-stable protein (HSP, 20.9 to 29.0%), Cd-rich granules (MRG, 9.9 to 19.5%), heat-denatured protein (6.0 to 8.5%), and organelle fractions (3.1 to 7.4%). The populations of H. spectabile with more Cd partitioned to cellular debris and biological detoxified metal (HSP + MRG) fractions have greater capacity to accumulate Cd, indicating the probable intrinsic mechanism to accumulate Cd. Therefore, H. spectabile has the considerable potential of phytoremediation for Cd-contaminated soils, but screening suitable populations according to soil Cd concentrations is necessary before used for phytoremediation of Cd-contaminated soils.

Metal concentrations in homing pigeon lung tissue as a biomonitor of atmospheric pollution.

Atmospheric pollution in urban areas is a major worldwide concern with potential adverse impacts on wildlife and humans. Biomonitoring can provide direct evidence of the bioavailability and bioaccumulation of toxic metals in the environment that is not available with mechanical air monitoring. The current study continues our evaluation of the usefulness of homing pigeon lung tissue as a biomonitor of atmospheric pollution. Homing pigeons (1-2, 5-6, and 9-10+ year old (yo)) collected from Guangzhou during 2015 were necropsied and concentrations of cadmium (Cd), lead (Pb), and mercury (Hg) were measured in lung tissue. Lung Cd and Pb concentrations were significantly greater in 9-10+-year-old pigeons compared with those in other age groups, indicating their bioavailability and bioaccumulation. Lung Pb and Cd concentrations measured in 5-yo pigeons collected from Guangzhou during 2015 were significantly lower than concentrations reported in 5-yo homing pigeons collected from Guangzhou during 2011 and correlated with concentrations measured using mechanical air monitoring. In addition to temporal differences, spatial differences in concentrations of Cd, Pb, and Hg reported in ambient air samples and in pigeon lung tissues collected from Beijing and Guangzhou are discussed.

Mazzaella laminarioides and Sarcothalia crispata as possible bioindicators of heavy metal contamination in the marine coastal zone of Chile.

The suitability of Mazzaella laminarioides and Sarcothalia crispata as heavy metal biomonitors of Cd, Cu, Hg, Pb, and Zn was assessed by comparing bioaccumulation of these elements in different life stages and frond sizes in samples from three locations, San Vicente Bay (industrial area), Coliumo, and Quidico (the latter as a reference station), where different degrees of heavy metal pollution are recorded. Bioaccumulation and bioconcentration factors of Cd, Cu, Hg, Pb, and Zn were evaluated. The two macroalgae species showed similar patterns, with higher values of Cu, Hg, Pb, and Zn in polluted areas. M. laminarioides bioaccumulated higher concentrations of all metals assessed than S. crispata, independent of life stage and frond size. The results also showed significantly higher Cu, Hg, Pb, and Zn concentrations (p<0.05) in water samples from San Vicente Bay than those measured in Coliumo and Quidico. Concentrations of Cd, Hg, Pb, and Zn in San Vicente Bay and Cd, Hg, and Pb in Coliumo and Quidico exceed the mean values considered to represent natural concentrations (Cu=3.00μgL-1; Zn=5.00μgL-1; Pb=0.03μgL-1; Cd=0.05μgL-1; Hg=0.05μgL-1); however, the concentrations recorded do not cause negative effects on the growth and survival of macroalgae. The assessment of heavy metals bioaccumulated in M. laminarioides and S. crispata, particularly Hg, Pb, and Zn, offers a reliable approach for pollution assessment in rocky intertidal environments. Cu and Cd concentrations in seawater samples from San Vicente and Coliumo Bays were significantly higher than in those from Quidico (p value <0.05); no significant differences in Cd concentrations were observed between San Vicente and Coliumo Bays (p<0.05). Exceptionally, Cd is bioaccumulated at high levels independent of its availability in the water, thus reaching high concentrations in control areas. High concentrations of metals like Cu and Zn may limit or inhibit Cd uptake in macroalgae, since the transport channels are saturated by some metals, reducing the accumulation of others. These macroalgae species offer good potential for the development of suitable heavy metal pollution survey tools in rocky intertidal environments.

Effect of soil cadmium concentration on three Chilean durum wheat cultivars in four environments

ABSTRACTDurum wheat (Triticum turgidum L. var durum) is a species that accumulates cadmium (Cd). Durum wheat cultivars differ in their absorption ability of Cd; therefore, identifying and selecting genetic material with low Cd accumulation reduces human exposure to this toxic element. In the present study, Cd concentration was evaluated in three Chilean durum wheat cultivars (Llareta-INIA, Corcolén-INIA, and Lleuque-INIA) grown in four Chilean locations with varying concentrations of Cd in soils. The objective of this study was to evaluate the response of these durum wheat cultivars to different doses of cadmium in terms of grain yield; Cd concentration in different plant tissues (grain, straw, roots); soil Cd concentration was also evaluated. Results show that grain yield was not affected by soil Cd; differences in Cd concentration in plant tissues were generally associated with location, cultivar, and soil Cd concentration. Grain Cd concentration in all three cultivars was classified in the low accumulation category for this metal; ‘Lleuque-INIA’ noted as having a very low accumulation.

Cadmium accumulation in three contrasting New Zealand soils with the same phosphate fertilizer history

Cadmium (Cd) concentration in New Zealand (NZ) agricultural soils has increased due to phosphate fertilizer application, but it is not clear whether soils with different properties accumulate Cd at similar rates for given P loadings. Here, the distribution of Cd was measured in three soils: the well-drained Horotiu series (Orthic Allophanic Soil in NZ soil classification, Typic Hapludand in US soil taxonomy), poorly-drained Te Kowhai series (Orthic Gley Soil in NZ classification, Typic Humaquept in US soil taxonomy) and an intergrade between them, Bruntwood series (Impeded Allophanic Soil in NZ soil classification, Aquic Hapludand in US soil taxonomy). All three soils often occur in the same paddock with the same fertilizer history, but have differing drainage and mineralogical characteristics, permitting an assessment of the potential for varying accumulation/translocation of Cd in contrasting soil conditions. Thirty soil profiles from ten paddocks on a dairy farm near Hamilton, NZ, with a uniform fertilizer history were sampled to depth of 60cm. The Cd concentration in topsoil (0–7.5cm) samples (mean of 0.79mgkg−1) was about 7–8 times greater than in deeper horizons (P<0.001). No significant differences in Cd concentration or fractionation among the soil series were detected. Cluster analysis showed that Cd, phosphorus (P) and uranium (U) were highly correlated, consistent with a common source, most likely phosphate fertilizer. The absence of a difference in the Cd depth profiles in the three soils indicates that Cd was preferentially adsorbed to the topsoil and was not significantly mobilized by drainage in the soils. The lack of difference in Cd distribution between contrasting soil series supports the use of one Cd management system tool for all of these soils.