Increasing Cadmium Concentration Research Articles

Single and combined effects of microplastics and cadmium on the sea cucumber Apostichopus japonicus

Microplastic pollution of the ocean has received extensive attention as plastic pollution increases globally, but the potential ecological risks caused by microplastic interactions with trace metals still require further research. In this study, Apostichopus japonicus was used to explore the individual and combined toxicities of cadmium (Cd) and microplastics and their effects on growth, Cd tissue accumulation, digestive enzymes, and gut microbes. The body weight gain and specific growth rate of animals exposed to a combination of high concentrations of Cd and microplastics decreased. The addition of high concentrations of cadmium to the diet led to an increase in cadmium content in the respiratory tree, digestive tract and body wall. Amylase, lipase and trypsin decreased to different degrees in the group treated with high concentrations of Cd/microplastics. Firmicutes were significantly reduced across multiple treatment groups, with the order Lactobacillales being the most significantly affected. Cd is the pollutant causing the greatest negative impact, but the presence of microplastics undoubtedly increases its toxicity.

Progress in the Study of the Absorption

Ramie ( Boehmeria nivea ) is notable for its ability to accumulate and adsorb cadmium from heavy metal-contaminated soil. The accumulation of cadmium is more pronounced at a low cadmium concentration in the soil, and decreases with increase in cadmium concentration because of the effects of cadmium toxicity. In this review, the absorption, accumulation, and tolerance to cadmium of ramie is summarized. The existing knowledge gaps and prospects for utilization of ramie are noted to provide a theoretical foundation for future research on the utility of ramie for remediation of heavy metal-contaminated soil and for ramie breeding. 

Absorption of Cadmium and its Effect on the Growth of Halfsib Family of Three Cocoa Clones Seedling

The issue of cadmium in cocoa beans has become one of the primary considerations in setting quality criteria in chocolate-consuming countries. Using rootstock genotypes that are tolerant to cadmium uptake can provide data on the absorption of cadmium into shoots for recovery. This study examined cocoa plants’ growth and physiological response to cadmium (Cd) accumulation. The research was carried out using polybags in the Greenhouse of the Indonesian Coffee and Cocoa Research Center using a half-sib family of cocoa aged 4 months after sowing. The study was designed using a completely randomized split-plot design with 3 replications. The parent plots were the half-sib families of Sulawesi 1, Sulawesi 2, and Scavina 6. The subplots were added with cadmium solution at 0 (control), 2, 4, and 8 ppm. The results showed that adding cadmium up to 8 ppm did not affect the growth and biomass of cocoa seedlings; however, it had a negative effect on plant physiological processes of the net assimilation rate and relative growth rate. Cadmium content in the tissue increased with increasing cadmium concentration in the growing medium. The accumulation of cadmium in roots was higher than that of shoots. Absorption of cadmium in the root tissue of Sulawesi 1 was higher than that of Scavina 6 and Sulawesi 2; genetic factors did not affect cadmium uptake in the shoots. There was a positive correlation between root dry weight and cadmium concentration in the tissue; the higher the dry weight of the root tissue, the higher the cadmium uptake in plants.

Integrated genomics and transcriptomics reveal the extreme heavy metal tolerance and adsorption potentiality of Staphylococcus equorum

In this study, we successfully isolated 11 species of cadmium-tolerant bacterium from Pu-erh rhizosphere soil, of which Staphylococcus equorum PU1 showed the highest cadmium tolerance, with a minimum inhibitory concentration (MIC) value of 500 mg/L. The cadmium removal efficiency of PU1 in 400 mg/L cadmium medium reached 58.7 %. Based on the Nanopore PromethION and Illumina NovaSeq platforms, we successfully obtained the complete PU1 genome with a size of 2,705,540 bp, which encoded 2729 genes. We further detected 82 and 44 indel mutations in the PU1 genome compared with the KS1039 and KM1031 genomes from the database. Transcriptional analysis showed that the expression of 11 genes in PU1 increased with increasing cadmium concentrations (from 0 to 200, then to 400 mg/L), which encoded cadmium resistance, cadmium transport, and mercury resistance genes. In addition, some genes showed differential expression patterns with changes in cadmium concentration, including quinone oxidoreductase-like protein, ferrous iron transport protein, and flavohemoprotein. Gene Ontology (GO) functions, including oxidation reduction process and oxidoreductase activity functions, and KEGG pathways, including glycolysis/gluconeogenesis and biosynthesis of secondary metals, were also considered closely related to the extreme cadmium tolerance of PU1. This study provides novel insight into the cadmium tolerance mechanism of bacteria.

Effect of Cadmium on Germination and Seedling Growth of Cicer arietinum, Cv.G130

Heavy metals contamination in agriculture, especially near industrial areas, is very common, and they are toxic and harmful to for thegrowth of plants. Biologically, cadmium (Cd) is a non-essential element for plants and it reduces the germination and seedling growthof Cicer arietinum. In the present study effects of different cadmium chloride concentrations (1, 10 and 50 mg-1) were investigated onseedling growth of C. arietinum, L cv. G130. The seedling growth studies were carried out in dark and light conditions. Germinationpercentage was recorded after 24 hours for both dark and light conditions. During the observation, it was found that the higherconcentration of cadmium, particularly 50 mg-1, significantly reduced plant growth. The length of epicotyl and radicle shows gradualinhibition as the cadmium concentration is increased from 10 to 50 mg-1 Cd. Similarly, fresh weight and dry weight also decreased withthe increased cadmium concentrations. It was noted that the higher concentration of Cd inhibited plant growth and the lower metalconcentration showed of plant growth promotion. However, studies reveal that the growth is promoted in 1 mg-1 Cd concentration (1ppm). Results confirmed cadmium’s toxic effect on chickpea seedling growth at higher concentrations

Detection of Cadmium Genotoxicity on Fatty Acids Desaturase-2 Genes in Safflower (Carthamus tinctorius)

Environmental pollution negatively affects the life activities of the living things of the environment and causes structural damages on the all living and inanimate things. The extent of the damage caused by human-made pollution to nature and the environment is increasing day by day. Heavy metal pollution is one of the most important causes of environmental pollution. Cadmium, which is one of the most important pollutants, is a highly toxic metal and is not used by living things, even in trace amounts. Cadmium is also a very toxic heavy metal for plants. As with other heavy metals, it triggers oxidative stress by increasing the production of reactive oxygen species in plant cells, causing DNA damage and abnormalities in DNA and RNA production. Safflower is a very important oil plant with high economic value and intensive use as a raw material in many sectors. In this study, in experimental groups prepared at different cadmium concentrations, the negative/genotoxic effects of cadmium on the mRNA expression levels of the FAD2 (FAD2-6, FAD2-7, FAD2-11) genes, which is responsible for the conversion of oleic acid to linoleic acid in different safflower varieties (Balci, Bdyas-04, Linas and Asol) has been determined by quantitative Real-Time PCR method. As a result, it has been detected that the decrease firstly in the expression of FAD2 genes at increasing cadmium concentrations in all cultivars. And also, re-increase at 160 and 320 mg L-1 which can be considered as critical points, have been accepted as an indication that the defense mechanism against stress is activated and FAD2 genes play a role in the defense against stress. In conclusion, the obtained data showed that FAD2 genes in safflower cultivars not only in the conversion of fatty acids but also play a critical role in defense against cadmium heavy metal stress.

N-acetylcysteine alleviates cadmium-induced testicular interstitial cell apoptosis by activating protein kinase B pathway

To investigate the regulation mechanism of N-acetylcysteine(NAC) on cadmium-induced apoptosis of mouse testicular interstitial cells based on protein kinase B pathway(AKT pathway). Mouse testicular mesenchymal cells(TM3) were divided into fourgroups according to different treatment, control group, cadmium group(Cd, 5, 10, 20, 30, 40 and 50 μmol/L), NAC group(NAC, 500 μmol/L) and NAC+Cd group(500 μmol/L NAC+20 μmol/L Cd). Cells of NAC+Cd group were pretreated with NAC for 30 min, and then combined with cadmium for 24 h. Cell viability was determined by CCK8. Hoechst staining was used to determine cell morphology. Cell apoptosis rate was analyzed by flow cytometry. Malondialdehyde(MDA) and glutathione(GSH) were measured simultaneously. Western blot was used to detect the expression levels of AKT protein, B-cell lymphoma-2(Bcl-2) and Bcl-2 associated X protein(Bax). Cadmium inhibited the proliferation of TM3 cells in a dose-effect relationship. Cell morphology observation showed that with the increase of cadmium concentration, the cells shrank, became round and even fell off, and appeared dense nuclear staining. The MDA level in Cd group was(1.56±0.11) μmol/mg prot, which was significantly higher than that in control group(P<0.01). Compared to the control group, the level of GSH was significantly decreased to(1.28±0.25) μmol/mg prot(P<0.01). NAC pretreatment could reduce the MDA content and increase the GSH level, and the difference was statistically significant compared with the Cd group(P<0.01). Western blot result showed that NAC pretreatment significantly increased levels of phosphorylated AKT and Bcl-2, the levels were 0.65±0.05 and 0.45±0.03, respectively(P<0.01). The Bax/Bcl-2 ratio was 1.54±0.15, which was significantly lower than that of the Cd group(P<0.01). NAC can inhibit cadmium-mediated TM3 cell damage and apoptosis, which may be related to the improvement of oxidative stress state, activation of TM3 AKT pathway and reduction of Bax/Bcl-2 ratio.

HISTOPATHOLOGICAL STUDIES OF EARTHWORM (Aporrectodea longa) EXPOSED TO CADMIUM

The histopathological studies of earthworm (Aporrectodea longa) exposed to cadmium was investigated. The earthworm was exposed to 0.25, 0.5, 1, 2 and 4 mg/kg of cadmium for 30 days in the laboratory. The procedure for the exposure was according to the Organisation for Economic Cooperation and Development (OECD) #207 recommended method for testing of chemicals. There were three replicates per treatment and 5 earthworms per jar of soil spiked with cadmium. Control groups were also prepared. Bioaccumulation of cadmium increased (p<0.05) with increase in cadmium concentration. The histopathological alterations were carried out in the clitellum and gizzard of earthworms. Mild to severe necrosis and distortion of muscles were observed in the cadmium concentrations of 0.25, 0.5, 1, 2, and 4 mg/kg and the effects increased with increase in concentration of the metal in the clitellum and gizzard. Vacuolisation and clearing of epithelial cells were observed in the clitellum. The results of this study revealed the effect of cadmium on the histological composition of Aporrectodea longa. The discharge of cadmium into terrestrial ecosystems should be discouraged as this could affect the health of earthworms whose ecological roles as ecosystem engineers could be impaired.

Physiological response of Vetiveria Zizanioides to cadmium stress revealed by Fourier transform infrared spectroscopy

The present paper deals with the physiological response of the changes in chemical contents in the root, stem and leaf of Vetiveria zizanioides seedlings stressed by excess cadmium using Fourier transform infrared spectroscopy technique. Cadmium accumulation in plant and distribution in subcellular by atomic absorption spectroscopy were tested under different concentrations cadmium stress. The results show that low cadmium concentrations (<3 mg·L−1), the stem tissue of Vetiveria zizanioides can uses osmosis of organic substances (e.g., carbohydrates and amino acids) to improve cadmium tolerance. Organic acids secreted by the root of the plant could chelate cadmium, and the membrane lipid peroxidation of root, stem and leaf arise. It may be associated with cadmium tolerance threshold of Vetiveria zizanioides. In addition, the plant accumulated large amounts of cadmium, up to a maximum of 212.49 mg · kg−1(the shoot) and 290.59 mg · kg−1 dry weight (the root) on 10 days when the plant was treated with 7 mg·L−1 cadmium. The cadmium in the shoot (stem and leaf) usually increased with increasing cadmium concentration. Cadmium accumulated in leaves was mainly distributed in the cytoplasm, followed by the cell wall, and was least distributed in the mitochondria and chloroplasts. These studies demonstrated that the potential of Fourier transform infrared spectroscopy is the non-invasive and rapid technique for monitoring of the plants stressed with heavy metals, and Vetiveria zizanioides is suitable for phytoremediation of cadmium -contaminated soils.

Study of structural, electromagnetic and dielectric properties of cadmium substituted Ni–Zn nanosized ferrites

Sol-gel auto-combustion method was adopted to prepare Cd2+ ions substituted Ni–Zn nanosized ferrites having a chemical formula Ni0.5Zn0.5-xCdxFe2O4 (0.0 ≤x≤0.4). Their structural, electromagnetic, and dielectric properties were investigated by using XRD, FE-SEM, EDS, FTIR, VSM, and IS. The XRD analysis revealed a single-phase cubic structure of all samples. The addition of cadmium increased the lattice constant and cell volume of Ni–Zn ferrite due to the difference in the ionic radii between Cadmium (0.97 ​Å) and Zinc (0.74 ​Å). FESEM images showed irregularly shaped grain sizes in the range of 40 to 73 ​nm with random orientations and some agglomeration. The FTIR analysis also confirmed the presence of spinal ferrite phase functional groups in all samples. The saturation magnetization decreased (from 89.51 to 71.32 emu/g) with increasing cadmium content. However, the remanent magnetization and coercivity parameters increased with an increase in cadmium content. The dc resistivity as a function of the temperature of all samples was investigated, and the activation energies were found to be in the range of 0.48 to 0.51 ​eV. The dielectric loss decreased with increasing cadmium content. However, the dielectric constant and dielectric loss tangent (tan) varied non-monotonically with increased cadmium content.

Enhanced blue-shift of the optical band gap in Cd-doped ZnO nanoparticles

Nanoparticles of ZnO prepared through an inexpensive chemical route were doped with controlled quantities of Cd in wt%. The samples were found to be polycrystalline in nature which is confirmed by XRD. They also matched with their respective Powder Diffraction Data files. Morphological and compositional studies were conducted using FESEM to confirm the grain size, texture and doping. Frequency dependent impedance spectroscopy demonstrated that the ac conductivity increases with frequency but decreases with increasing cadmium concentration. Analysis on the samples shows that the absorbance does not significantly change with doping which is further established from the bandgap calculations using the reflectance graphs. Contrary to the common observation, the optical band gap of Cd-doped ZnO is blue-shifted from 3.47 to 3.56 eV as the doping weight percentage is increased to 3 %. This can also confirmed in FTIR analysis as signatures of new peaks in doped samples are obtained. From FTIR spectra it has been observed that the vibrational modes of the doped samples are around 473 cm-1and 475 cm−1. It also confirms a new peak which is due to defects created by incorporation of Cd in the host lattice.

Hepatosomatic and Renosomatic Indices of &amp;lt;i&amp;gt;Anabas testudineus&amp;lt;/i&amp;gt; Exposed to Various Levels of Cadmium

Cadmium has a high level of toxicity and can have adverse health effects on living organisms including fish. This study is conducted to identify the effects of cadmium exposure on the Hepatosomatic Index (HSI) and Renosomatic Index (RSI) of Anabas testudineus. Anabas testudineus is exposed to four different cadmium treatment groups. The fishes were exposed to four treatment groups of different cadmium concentrations (0.000 mg/L, 0.005 mg/L, 0.010 mg/L and 0.015 mg/L) for 16 weeks. The results showed a decreasing trend of HSI value increasing cadmium concentration and exposure time. However, the opposite trend was observed with RSI where the higher the cadmium concentration over an increased exposure time, the higher the RSI. In conclusion, the study outcome shows significant changes in the value of HSI and RSI between different treatment groups with exposure time.

Low phosphate mitigates cadmium‐induced oxidative stress in Saccharomyces cerevisiae by enhancing endogenous antioxidant defence system

Cadmium is a highly toxic heavy metal that causes many harmful effects on human health and ecosystems. Metal chelation-based techniques have become a common approach for the treatment of metal poisoning and also for the remediation of metal contamination. Phosphate, an essential nutrient required for key cellular functions, has been supposed to be effective in reducing cadmium bioavailability, possibly through its chelating potential. In this study, we explored the effects of phosphate on cadmium toxicity and cellular response to cadmium stress in the eukaryotic model Saccharomyces cerevisiae. Our results reveal that cadmium toxicity is unexpectedly enhanced during phosphate repletion and optimal phosphate levels for yeast growth under cadmium stress conditions decline with increasing cadmium concentrations. The profound cadmium toxicity during phosphate repletion is unlikely to result from either elevated cadmium accumulation or dysregulated homeostasis of essential metals, but rather due to increased production of intracellular reactive oxygen species. We show that, under phosphate-depleted conditions, the activities of antioxidant enzymes, especially Mn-superoxide dismutase and catalase, are significantly promoted through transcriptional upregulation. Our findings highlight the important role of cellular response to phosphate limitation in mitigating cadmium toxicity and endogenous oxidative stress through the enhancement of antioxidant enzyme activity.

X-ray, IR and SEM studies on some Li-Cd ferrites

Lithium-Cadmium ferrites with general formula Li0.5-x/2 Fe2.5-x/2 Cdx O4 (with x = 0,0.1,0.2....,0.7) were prepared by standard ceramic method. X-ray diffraction studies confirms single phase formation and lattice parameters were calculated. The crystal structure is cubic and lattice parameter increases with increasing Cd content. The infrared absorption (IR) spectra of all the samples were recorded in the range 200-800 cm-1 at room temperature in the KBr medium. Lithium ferrite shows four principal bands and some shoulders have been observed. The force constants Kt and Ko were calculated using Waldron's analysis. Scanning electron microscopy studies shows increase in grain size up to x = 0.1 and then the grain size decreases with increase in cadmium content.

Fertilization and soil pH affect seed and biomass yield, plant morphology, and cadmium uptake in hemp (Cannabis sativa L.)

The phytoremediation potential of industrial hemp (Cannabis sativa L.) becomes a new target of hemp cultivation. The ability to accumulate cadmium depends on genetic, anatomical and physiological characteristics of the varieties. The published data show that the level of fertilization affects many metabolic pathways, the development of plants and cannabinoid concentration. In addition, there are inconsistent data on the cadmium accumulation capacity depending on the mineral nutrition and pH. A study was carried out to assess the potential of two hemp varieties (‘Henola’ and ‘Białobrzeskie’) as a decontaminator of cadmium, depending on soil pH and phosphorous fertilizer level. The influence of pH, fertilization and cadmium concentration in the soil on plant morphology and on the yield of seeds and biomass were also assessed. The soil with two different pH was used in the experiment: acidic (pH 4) and alkaline (pH 7.5). Two concentrations of aqueous solution of cadmium nitrate (Cd(NO3)2) were added to the soil to obtain final concentration of Cd: 4 mg/kg and 8 mg/kg of soil, respectively. The phosphorous fertilizer was supplied in the amounts of: 50 kg/ha, 100 kg/ha, 150 kg/ha. The cadmium content in soil and in hemp plants was determined with a flame atomic absorption spectrophotometry and a plasma optical emission spectrometry (ICP-OES), respectively. Based on two years of experiments, the highest cadmium concentration in seeds and biomass, were revealed for Henola variety, when fertilizer was applied in the amount of 150 kg/ha. The results revealed that the fertilization ant pH level are important factors in the cultivation of hemp. They affect the intensity of cadmium uptake from the soil. Higher soil pH was correlated with the highest concentration of Cd in seeds and straw of Białobrzeskie variety. Such a relationship has not been demonstrated in the case of the Henola variety. The highest BCF (bioconcentration factor) value was calculated for Cd uptake in ‘Henola’ biomass. Increased cadmium concentration in the soil did not adversely affect development and growth of two hemp varieties studied. The phytoremediation potential of individual hemp varieties is different. Higher pH increases the cadmium uptake by some hemp varieties, but in the case of other varieties this relationship is reversed. It is necessary to assess the phytoremediation potential of each hemp cultivar in different agrotechnical conditions.

Multiple environmental benefits of alternate wetting and drying irrigation system with limited yield impact on European rice cultivation: The Ebre Delta case

The AWD is an irrigation technology for rice cultivation, consisting in implementing alternate draining and flooded periods over the growing season, that delivers multiple environmental benefits, such as reduced water consumption, CH4 emissions and arsenic (As) grain content, but can be offset by yield losses. The trade-offs between the agronomic and environmental effects of AWD are crop context-dependent and they also vary among the different versions of AWD studied. Therefore, the implementation of a safe AWD needs to be preceded by studies conducted within a specific rice cropping system. A two-year field experiment was conducted to assess the effect of AWD on grain yield, As and heavy metal content in grains, and greenhouse gas emissions in nine representative European rice cultivars grown in a Mediterranean growing area. The experiment was performed in a split-plot design with four replications. The study revealed a significant cultivar effect on the agronomic response to AWD. Among the studied cultivars, one of them performed as tolerant to AWD while a group formed by four cultivars showed slight non-significant yield decline. AWD significantly reduced CH4 emissions and the global warming potential by 90% being such a large mitigation capacity explained by the negligible N2O emissions found in both water treatments. Finally, the implementation of AWD significantly reduced by ca. 40% As grain concentration but increased cadmium content, though the levels remained below the recommended thresholds. Further, AWD increased key nutritional elements like cupper, selenium, and zinc. In conclusion, this study confirms that AWD can be safely implemented in Mediterranean rice cultivation conditions with limited or null yield impact while obtaining the associated environmental benefits of this practice

Prioritization of biological processes based on the reconstruction and analysis of associative gene networks describing the response of plants to adverse environmental factors

Methods for prioritizing or ranking candidate genes according to their importance based on specif ic criteria via the analysis of gene networks are widely used in biomedicine to search for genes associated with diseases and to predict biomarkers, pharmacological targets and other clinically relevant molecules. These methods have also been used in other f ields, particularly in crop production. This is largely due to the development of technologies to solve problems in marker-oriented and genomic selection, which requires knowledge of the molecular genetic mechanisms underlying the formation of agriculturally valuable traits. A new direction for the study of molecular genetic mechanisms is the prioritization of biological processes based on the analysis of associative gene networks. Associative gene networks are heterogeneous networks whose vertices can depict both molecular genetic objects (genes, proteins, metabolites, etc.) and the higher-level factors (biological processes, diseases, external environmental factors, etc.) related to regulatory, physicochemical or associative interactions. Using a previously developed method, biological processes involved in plant responses to increased cadmium content, saline stress and drought conditions were prioritized according to their degree of connection with the gene networks in the SOLANUM TUBEROSUM knowledge base. The prioritization results indicate that fundamental processes, such as gene expression, post-translational modif ications, protein degradation, programmed cell death, photosynthesis, signal transmission and stress response play important roles in the common molecular genetic mechanisms for plant response to various adverse factors. On the other hand, a group of processes related to the development of seeds (“seeding development”) was revealed to be drought specif ic, while processes associated with ion transport (“ion transport”) were included in the list of responses specif ic to salt stress and processes associated with the metabolism of lipids were found to be involved specif ically in the response to cadmium.

Cadmium is deposited to the exoskeleton during post-ecdysial mineralization in the blue crab, Callinectes sapidus

Despite the fact that cadmium has been reported to be present in crustacean exoskeletons, no study has previously been done to determine when cadmium is deposited to the exoskeleton and what effects cadmium has on the shell-hardening process. This project sought to address these scientific questions using the blue crab, Callinectes sapidus, as the model crustacean. It was hypothesized that cadmium would be incorporated into the exoskeleton during post-ecdysial mineralization through ionic mimicry because of the resemblance between cadmium and calcium ions. To test this, soft shell blue crabs were injected with cadmium chloride, and cadmium content in the exoskeleton was subsequently quantified using ICP-OES. Carbonic anhydrase catalyzes the carbon dioxide hydration reaction, which generates bicarbonate ions essential for calcium carbonate formation in the shell. The effect of cadmium injection on epidermal carbonic anhydrase activity as well as exoskeletal calcification was also investigated. It was found that cadmium injection into post-ecdysial Callinectes sapidus significantly increased cadmium content in the exoskeleton, suggesting that cadmium is deposited to the new exoskeleton during post-ecdysial mineralization. Cadmium administration had no effect on epidermal carbonic anhydrase activity or exoskeletal calcification. Interestingly, magnesium content in the exoskeleton was significantly elevated following cadmium treatment. This is most likely a “pseudo” effect stemming from the cadmium-induced reduction in exoskeleton weight. The fact that cadmium had no effect on exoskeletal calcium and that cadmium decreased the weight of the exoskeleton suggests that cadmium has a detrimental effect on the formation of the organic matrix of the exoskeleton. The presence of cadmium in control crabs and exuviae and the amplification of cadmium content in cadmium-treated crabs clearly show that crab shell is a cadmium repository and can be used as a biomarker for aquatic cadmium pollution.

Associations between blood cadmium and endocrine features related to PCOS-phenotypes in healthy women of reproductive age: a prospective cohort study

BackgroundCadmium is an endocrine disrupting chemical that affects the hypothalamic-pituitary-gonadal axis. Though evidence suggests its potential role in altering androgen synthesis and metabolic pathways that are characteristic of polycystic ovary syndrome (PCOS), its relation in healthy women of reproductive age is largely unknown. As women with mild sub-clinical features of PCOS who do not meet the diagnostic criteria of PCOS may still experience reduced fecundability, investigating associations between cadmium and PCOS-phenotypes among healthy women may provide unique insight into the reproductive implications for many on the PCOS spectrum. Therefore, the objective of this study was to evaluate associations between cadmium and androgens, anti-Müllerian hormone (AMH), and metabolic markers in women of reproductive age.MethodsThis was a prospective cohort study of 251 healthy premenopausal women without self-reported PCOS (mean age 27.3 years and BMI 24.1 kg/m2). Cadmium was measured in blood collected at baseline. Reproductive hormones and metabolic markers were measured in fasting serum 8 times per menstrual cycle for 2 cycles. Linear mixed models and Poisson regression with a robust error variance were used to examine associations between cadmium and reproductive hormones and metabolic markers and anovulation, respectively.ResultsMedian (interquartile range) blood cadmium concentrations at baseline were 0.30 (0.19–0.43) µg/L. Higher levels of testosterone (2.2 %, 95 % confidence interval [CI] 0.4, 4.1), sex hormone-binding globulin (2.9 %, 95 % CI 0.5, 5.5), and AMH (7.7 %, 95 % CI 1.1, 14.9) were observed per 0.1 µg/L increase in cadmium concentrations. An 18 % higher probability of a mild PCOS-phenotype (95 % CI 1.06, 1.31), defined by a menstrual cycle being in the highest quartile of cycle-averaged testosterone and AMH levels, was also found per 0.1 µg/L increase in cadmium levels. No associations were observed for insulin and glucose. These findings were consistent even after analyses were restricted to non-smokers or further adjusted for dietary factors to account for potential sources of exposure.ConclusionsOverall, among healthy reproductive-aged women, cadmium was associated with endocrine features central to PCOS, but not with metabolic markers. These suggest its potential role in the hormonal milieu associated with PCOS even at low levels of exposure.

Effects of cadmium stress on growth and physiological characteristics of sassafras seedlings

The effects of cadmium stress on the growth and physiological characteristics of Sassafras tzumu Hemsl. were studied in pot experiments. Five Cd levels were tested [CT(Control Treatment) : 0 mg/kg, Cd5: 5 mg/kg, Cd20: 20 mg/kg, Cd50: 50 mg/kg, and Cd100: 100 mg/kg]. The growth and physiological characteristics of the sassafras seedlings in each level were measured. The results showed that soil Cd had negative influences on sassafras growth and reduced the net growth of plant height and the biomass of leaf, branch and root. Significant reductions were recorded in root biomass by 18.18%(Cd5), 27.35%(Cd20), 27.57%(Cd50) and 28.95%(Cd100). The contents of hydrogen peroxide decreased first then increased while malondialdehyde showed the opposite trend with increasing cadmium concentration. Decreases were found in hydrogen peroxide contents by 10.96%(Cd5), 11.82%(Cd20) and 7.02%(Cd50); increases were found in malondialdehyde contents by 15.47%(Cd5), 16.07%(Cd20) and 7.85%(Cd50), indicating that cadmium stress had a certain effect on the peroxidation of the inner cell membranes in the seedlings that resulted in damage to the cell membrane structure. Superoxide dismutase activity decreased among treatments by 17.05%(Cd5), 10,68%(Cd20), 20.85%(Cd50) and 8.91%(Cd100), while peroxidase activity increased steadily with increasing cadmium concentration; these results suggest that peroxidase is likely the main protective enzyme involved in the reactive oxygen removal system in sassafras seedlings. Upward trends were observed in proline content by 90.76%(Cd5), 74.36%(Cd20), 99.73%(Cd50) and 126.01%(Cd100). The increase in proline content with increasing cadmium concentration indicated that cadmium stress induced proline synthesis to resist osmotic stress in the seedlings. Compared to that in CT, the soluble sugar content declined under the different treatments by 32.84%(Cd5), 5.85%(Cd20), 25.55%(Cd50) and 38.69%(Cd100). Increases were observed in the soluble protein content by 2.34%(Cd5), 21.36%(Cd20), 53.15%(Cd50) and 24.22%(Cd100). At different levels of cadmium stress, the chlorophyll content in the seedlings first increased and then decreased, and it was higher in the Cd5 and Cd20 treatments than that in the CT treatment. These results reflected that cadmium had photosynthesis-promoting effects at low concentrations and photosynthesis-suppressing effects at high concentrations. The photosynthetic gas exchange parameters and photosynthetic light-response parameters showed downward trends with increasing cadmium concentration compared with those in CT; these results reflected the negative effects of cadmium stress on photosynthesis in sassafras seedlings.