Accumulation Of Trace Elements Research Articles

Effect of co-application of wastewater and freshwater on the physiological properties and trace element content in Raphanus sativus: soil contamination and human health.

Nowadays, the use of wastewater for crop irrigation is increasing at global scale mainly due to freshwater scarcity and economic benefits. However, the presence of different types of pollutants including the trace elements (TEs) poses a serious threat to environmental and human health. This pot study evaluated the effect of alone and mixed irrigation water [wastewater (WW) with canal water (CW) and tube-well water (TW)] on TEs build-up in the soil, their soil-plant transfer and allied health hazards in District Vehari. The WW samples were mainly contaminated with Cd (0.03mg/L), Cr (1.45mg/L), Cu (0.35mg/L) and Ni (0.40mg/L). The CW contained high levels of Cr and Fe, while TW was contaminated with Pb and Cr. In soil, the concentrations of Cd, Fe and Mn exceeded their respective limit values for all the treatments. Among all the treatments, TEs concentration was found highest in WW-3 irrigated soil. Application of all the treatments resulted in TEs (Cu, 60.1mg/kg; Cd, 8.2mg/kg; Ni, 39.9mg/kg; Fe, 4411mg/kg; Zn, 111.3mg/kg and Pb, 44.5mg/kg) accumulation mainly in the edible parts of Raphanus sativus. Compared to other treatments, TW and TW + CW irrigated plants accumulated higher levels of TEs. Results showed linear trends among TEs accumulation and alterations in physiological attributes of R. sativus. High TEs accumulation in TW irrigated treatments (TW + WW-1 and TW + CW) caused maximum H2O2 production, lipid peroxidation and decline in plant pigments. Risk assessment parameters showed both carcinogenic and non-carcinogenic risks for all the irrigation treatments due to high TEs contents in edible tissues. It is concluded that alone or combined application of WW, TW and CW is not fit for vegetable irrigation, in the studied area, due to high TEs contents.

Copper Tolerance Mediated by FgAceA and FgCrpA in Fusarium graminearum.

All organisms must secure essential trace elements (e.g., Cu) for survival and reproduction. However, excess trace element accumulation in cells is highly toxic. The maintenance of copper (Cu) homeostasis has been extensively studied in mammals, bacteria, and yeast but not in plant pathogens. In this study, we investigated the molecular mechanisms of copper tolerance in Fusarium graminearum, the important wheat head scab fungus. RNA-seq revealed induced expression of the P-type ATPase transporter FgCrpA and metallothionein (MT) FgCrdA after excess Cu treatment. Deletion of FgCrpA but not FgCrdA resulted in reduced tolerance to Cu toxicity. The “Cu fist” transcription factor FgAceA was involved in Cu detoxification through activation of FgCrpA. △FgAceA was more sensitive to copper toxicity than △FgCrpA and overexpression of FgCrpA restored copper tolerance in △FgAceA. FgAceA negatively regulated aurofusarin production and its biosynthetic gene expression. △FgCrpA and △FgAceA were reduced in virulence in flowering wheat heads and synthesized decreased amounts of the mycotoxin deoxynivalenol when challenged with excess Cu. Taken together, these results suggest that mediation of Cu tolerance in F. graminearum mainly relies on the Cu efflux pump and that FgAceA governs Cu detoxification through activation of FgCrpA.

Integrated Monitoring with Moss-Bag and Mussel Transplants in Reservoirs

For the first time, transplants with moss-bags and mussels together were applied to study the water quality in standing water bodies. The tested species: Fontinalis antipyretica Hedw. and Sinanodonta woodiana (Lea, 1834) were collected from unpolluted sites and analyzed to obtain background levels. Then, the moss and mussels were left in cages for a period of 30 days in three reservoirs where both are not present naturally. Two of the reservoirs suffer from old industrial contamination and one is affected by untreated wastes. Twenty-four compounds were studied, among them trace elements Al, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Zn and organic priority substances: six polybrominated diphenyl ethers (PBDEs) congeners and short-chain chlorinated paraffins (SCCPs). The trace element accumulation was significant after the exposition period in all studied stations. PBDEs and SCCPs were also accumulated up to two times more in the moss tissues. PBDEs in the mussels exceeded the environmental quality standard (EQS). The applied combined transplants, and especially the moss-bags, revealed severe contamination with heavy metals not detected by the water samples. The moss and the mussel followed a different model of trace element and PBDEs accumulation. The SCCPs levels were alarmingly high in all plant samples. The study confirmed PBDEs and SCCPs as bioaccumulative compounds and suggested that an EQS for SCCPs in biota needs to be established.

Mineral and Fatty Acid Content Variation in White Oat Genotypes Grown in Brazil.

A healthy diet is directly associated with a nutrient-rich and toxic contaminant poor intake. A diet poor in diversity can lead to micronutrient deficiency. The intake of functional foods can provide benefits in the prevention and treatment of diseases. Oats are a functional food; are a source of soluble fiber, lipids, proteins, vitamins, minerals, and polyphenols; and are low in carbohydrate content. Thus, in this study, we characterize mineral accumulation, fatty acid composition, and the absence of contaminants in oat genotypes to evaluate the potential of this cereal as food to minimize the effects of micronutrient deficiency. Most of the oat genotypes showed higher mineral levels than other cereals such as wheat, rice, and maize. FAEM 5 Chiarasul, Barbarasul, UPFA Ouro, URS Altiva, URS Brava, and URS Taura showed higher iron concentration while URS Brava showed the highest zinc concentration. The oat genotypes did not show significant arsenic, strontium, and cadmium accumulation. Considering the accumulation of trace elements in the grain, little genetic diversity among the analyzed oat accessions was detected, dividing into two groups. Regarding fatty acid composition, IPR Afrodite, FAEM 4 Carlasul, FAEM 5 Chiarasul, URS Taura, Barbarasul, and URS 21 showed higher essential fatty acid concentrations. These genotypes can be used in crosses with URS Brava, which displayed a higher Fe and Zn accumulation and is genetically distant from the other cultivars. Oat is a functional food showing ability for the accumulation of minerals and also essential fatty acids.

Intensity of heavy metal accumulation in plants of Silybum marianum L. in conditions of field rotation

Intensity of heavy metal accumulation in plants of Silybum marianum L. in conditions of field rotation

Fava bean intercropping with Sedum alfredii inoculated with endophytes enhances phytoremediation of cadmium and lead co-contaminated field

Phytoremediation coupled with agro-production is considered a sustainable strategy for remediation of trace element contaminated fields without interrupting crop production. In this study hyperaccumulator Sedum alfredii was intercropped with a leguminous plant fava bean (Vicia fava) in cadmium (Cd) and lead (Pb) co-contaminated field to evaluate the effects of intercropping on growth performance and accumulations of trace elements in plants with plant growth promoting endophyte (PGPE) consortium application. The results showed, compared with monoculture, intercropping coupled with inoculation application promoted biomass as well as Cd and Pb concentrations in individual parts of both plants, thus increasing the removal efficiencies of trace elements (4.49-folds for Cd and 5.41-folds for Pb). Meanwhile, this superposition biofortification measure maintained normal yield and nutrient content, and limited the concentration of Cd and Pb within the permissible limit (<0.2 mg kg−1 FW) in fava bean during the grain production. These results demonstrated a feasible technical system for phytoremediation coupled with agro-production in slightly or moderately Cd and Pb co-contaminated field, and also provided useful information for further investigation of interaction mechanisms between intercropping and PGPEs inoculation.

A Comparative Assessment of Trace Element Accumulation in Native and Improved Rice (Oryza sativa L.) Varieties Grown Under Different Conditions of Fertilizer Application.

Rice (Oryza sativa L.) is the main food crop cultivated in Sri Lanka, and different varieties of rice are grown under different conditions of fertilizer application throughout the country. Since the consumption of rice is extremely high, it is considered as the major dietary source for macro- and micro-nutrients and also for toxic trace elements. The main objective of this study was to investigate and compare trace element levels in native and improved rice varieties that were grown under both organic and inorganic chemical fertilizers and also under unfertilized conditions. Rice grains were collected from a plot experiment with seven native and seven improved rice varieties that were treated with organic and inorganic fertilizers. Contents of macro-nutrients (Na, K, Ca and Mg) and trace elements (Cd, As, Pb, Cr, Mn, Co, Ni, Cu, Zn and Ba) in rice grains were measured by inductively coupled plasma mass spectrometry. The results indicated that rice cultivated using inorganic fertilizers showed the highest mean trace element contents while organic fertilizer-treated improved rice varieties showed the lowest Cd (0.10mg/kg) which is lower than the maximum permissible level (0.2μgg-1). The highest mean value of Cd (0.32mg/kg) was recorded in native rice varieties grown in plots with chemical fertilizer applications. However, the As content in rice samples collected from all treatment conditions indicated contents lower than the maximum permissible level. Rice cultivated in plots that were treated with chemical fertilizer showed the highest mean macro-nutrient contents.

Особенности накопления йода в мышцах кроликов на фоне использования антиоксидантов в липосомальной форме

Abstract. The problem of iodine saturation of livestock products for residents of most regions of our country requires a detailed study. One of the factors is the obtaining of livestock products enriched with organic iodine. The study of the degree of accumulation of iodine in the muscle tissue of rabbits at the background of the use of liposomal form of antioxidants enriched with organic iodine (LFA) was the main purpose of the research. Methods. An experiment on rabbits of the California breed were used. The first control group received the main diet (MD) in the form of a granular mixture. The experimental second group was given LFA based on White sea laminarias at the rate of 250 g per ton of feed mixture of MD. The third experimental group was injected with MD the LFA with Black sea Cystoseira. The formation of meat indicators, chemical analysis of muscle tissue, the level of accumulation of trace elements, including iodine in muscle tissue was studied indicators. Results. Based on the somatometric method of evaluating rabbits, it was found that the young animals of the experimental groups form a more eirisomus-type body (from 60 to 70 % of the total population). All indicators of the interactions of somatic parameters in the young groups II and III positive and highly significant correlation, and the correlation index of the density of the body correlated positively with body length (r = +0,67, p ≤ 0.01), chest girth (r = +0,86, p ≤ 0.001), length of loin (r = +0,61, p ≤ 0,01), the length of the backside (r = +0.71, p ≤ 0.001) and head measurement (r = +0,57, p ≤ 0.05). An improvement of the indicators of slaughter of experimental groups of young animals was stated. The slaughter weight increases by 12.2 %, and the mass of internal organs responsible for digestion by 4.5–43.8 %. A percentage of increase in muscle tissue during boning by 10.0–15.9 % and a decrease in the proportion of low-value parts in the carcass-bone tissue by 8.6–9.9 % was stated. Iodine in the average sample of muscle tissue of the experimental groups increases by 91.8 mcg (p ≤ 0.05) in animals of the second group and by 113.3 mcg (p ≤ 0.05) of the third group.

Maternal and embryonic trace element concentrations and stable isotope fractionation in the smalleye smooth-hound (Mustelus higmani)

Here, we evaluate maternal offloading of 16 trace elements (Essential: Co, Cr, Cu, Fe, Mn, Ni, Se and Zn; Nonessential: Al, As, Ba, Cd, Hg, Pb, Tl and U) and determine mother-offspring isotopic fractionation of δ13C and δ15N in muscle and liver tissue of four pregnant Mustelus higmani and 18 associated embryos sampled from the Amazon Coast of Brazil. Embryo muscle tissue had significantly higher concentrations of most trace elements when compared to mothers, with the exception of Hg. Embryo liver accumulated more nonessential elements than muscle (n = 7 vs. 0, respectively), while the Se:Hg molar ratio was >1 in liver and muscle of both mothers and embryos. Livers of embryos were moderately enriched in δ13C and δ15N when compared to that of their mother. Negative correlations were observed between embryo body length and δ13C and trace elements concentrations. We conclude that mothers offload a large portion of all essential elements and Al, As and Pb to their young and that the isotopic fractionation of embryos reflects maternal diet and habitat occupied, with δ13C diluted with embryonic growth. We also show that muscle and liver accumulate trace elements at different rates relative to the body length of embryos. The Se:Hg molar ratio suggests that Se could play a protective role against Hg toxicity during early stages of M. higmani embryonic development.

Trace element accumulation potential in lemongrass varieties (Cymbopogon species) and prediction through regression model equations followed by path analysis: a field study

A field investigation was conducted to monitor the trace element accumulation pattern and potential in lemongrass varieties when cultivated in varying concentrations of tannery sludge contaminated soils. Regression model equations were developed to predict the trace elements concentration in lemongrass plant parts. Model efficiency values ranged between 0.53 and 0.85 for roots and 0.50 to 0.77 for shoots. R2 for all the equations was high and ranged between 0.52 and 0.95 for roots and 0.50 to 0.91 for shoots. Path analysis coefficients revealed the status of interdependence between soil properties and heavy metal concentrations in plant tissues and their translocation pattern in the same. TF > 1 for Ni and Pb was recorded in all test varieties at different tannery sludge concentrations in soil and for Cd in Suwarna variety grown in sole TS. BAF>1 and BAC>1 for Ni and Pb was observed for all test varieties. BCF>1 for Cr was found in Suwarna variety at sole tannery sludge. It can be concluded that lemongrass can accumulate lead and nickel in its harvestable plant parts. Hence, it can act as a suitable phytoextractor for the same metals. Range of essential oil content (percentage) varied in all test varieties i.e. Shikhar (1.04–1.29), Krishna (0.94–1.05), Suwarna (0.82–0.95) and Chirharit (0.87–1.06) at different tannery sludge concentrations. Moreover, heavy metal content in the essential oil of all test varieties was found to be within the permissible limits, hence cultivation of lemongrass can be recommended at metal contaminated sites with minimum risk of food chain contamination.

Trace elements and stable sulfur isotopes in plants of acid mine drainage area: Implications for revegetation of degraded land

The abundances of trace elements, a low pH of water and soil in areas impacted by the acid mine drainage (AMD) may cause an excessive uptake of potentially toxic elements and nutritional imbalances in plants. Metal-tolerant, native plants are used for revegetation of degraded mining areas. We established levels of selected trace elements and stable sulfur isotopes in the above-ground plant biomass collected in a mining area in south-central Poland. In 2016, 20 samples of the most common species were collected from sites with a different influence of acid mine drainage and analyzed for trace elements by the inductively coupled plasma mass spectrometry technique. On the basis of the results obtained in 2016, the most contaminated site was selected for a more detailed study, in which sulfur contents and stable sulfur isotope ratios were determined together with trace elements in 17 samples. The results confirmed that the plants native to the AMD area efficiently accumulated trace elements, especially As and rare earth elements. Mosses showed the highest content of trace elements, but exhibited the lowest concentrations of sulfur accompanied by the highest δ34S values. It has been shown for the first time that stable sulfur isotope composition of AMD plants in south-central Poland is significantly depleted in the 34S isotope showing an average δ34S value of –10.5‰ in comparison with positive δ34S values in local vegetation growing outside the AMD area and in local precipitation.

Regional assessment of trace element concentrations in arrow squids (Nototodarus gouldi, N. sloanii) from New Zealand waters: Bioaccessibility and impact on food web and human consumers

The New Zealand arrow squids, Nototodarus gouldi and N. sloanii, play an important role in the marine food web, and are both economically important fishery species. This study compares trace element concentrations (As, Cd, Co, Cr, Cu, Fe, Hg, Ni, Mn, Pb, U, and Zn) in these animals from different fishing locations within New Zealand’s Exclusive Economic Zone (Auckland Islands, Chatham Rise, Dunedin, Golden Bay, Taranaki, and West Coast of the South Island). Muscular mantle (the tissue usually consumed by humans) and digestive gland tissue (the primary organ for trace element accumulation) concentrations were compared among regions, revealing size, species, and sampling location effects. Overall, N. gouldi had higher concentrations of As and Zn. The Taranaki region had the highest concentrations for Cd, Co, Cu, and Zn in both tissues analysed. To assess the bioaccessibility of these trace elements to humans, an in-vitro digestion simulation experiment was conducted, revealing bioavailable concentrations overall below the maximum levels presently considered tolerable for human consumption. However, the in-vitro digestion had no observable effect upon Cd concentrations in arrow squid mantle tissue (implying that the measured concentrations are bioaccessible to humans), and revealed that Cd had the highest potential impact on marine food webs and human health. Digestive gland concentrations in particular indicate that arrow squids can be considered important vectors for trace element transfer to top predators (mean concentration for Cd: 123 ± 148 μg g−1 dw), with region-specific differences.

Accumulation of trace elements in muscle, gill and liver of fish species (Capoeta umbla and Luciobarbus mystaceus) in the Tigris River (Turkey), and health risk assessment

Two fish species (Capoeta umbla and Luciobarbus mystaceus) were collected from the Tigris River (Turkey), and tissues (gill, muscle and liver) of fish samples were analyzed for Cd, As, Mn, Cr, Cu, Co and Ni using the inductively coupled plasma-tandem mass spectrometry. Significant differences were present between fish species in regard to trace element (TE) concentrations in muscle for Mn, in liver for Cu, Cd and Mn, and in gill for As, Co, Cu and Cd (p < 0.05). Liver had the highest total TE concentration, followed by gill and muscle. Significant negative correlations were recorded between fish size (length and weight) and TE concentrations in the tissues. Both fish species showed no gender differences in TE accumulation in muscle, gill and liver (p > 0.05). The estimated daily intakes for all TEs were much lower than the tolerable daily intakes. The target hazard quotient (THQ) and total THQ values of all TEs did not exceed 1, which means that non-carcinogenic health effects are not expected for the consumers. Arsenic carcinogenic risk values were within acceptable range. Mean Cd concentrations in muscle tissue of both fish species exceeded the maximum permissible limit set by the European Commission Regulation, while mean concentrations of As, Cr and Cu were below the legislated limits.

Patterns of Trace Element Accumulation in Waterfowl Restricted to Impoundments Holding Coal Combustion Waste.

Waterfowl are often exposed to and readily accumulate anthropogenic contaminants when foraging in polluted environments. Settling impoundments containing coal combustion waste (CCW) enriched in trace elements such as arsenic (As), selenium (Se), and mercury (Hg) are often used by free-ranging migratory and resident waterfowl and represent potential sources for contaminant uptake. To assess accumulation of CCW contaminants, we experimentally restricted waterfowl to a CCW-contaminated impoundment and quantified trace element burdens in blood, muscle, and liver tissues over known periods of exposure (between 3 and 92 d). From these data we developed models 1) to predict elemental bioaccumulation with increased exposure time, and 2) to predict muscle/liver burdens based on concentrations in blood as a nondestructive sampling method. Although Hg and As did not bioaccumulate in our waterfowl, we observed an increase in Se concentrations in muscle, liver, and blood tissues over the duration of our experiment. Furthermore, we found that blood may be used as an effective nondestructive sampling alternative to predict muscle and liver tissue concentrations in birds contaminated with Se and As through dietary exposure. These data provide unique insights into accumulation rates of contaminants for waterfowl utilizing habitats contaminated with CCW and demonstrate the efficacy of nonlethal sampling of waterfowl to quantify contaminant exposure. Environ Toxicol Chem 2020;39:1052-1059. © 2020 SETAC.

Health risks from trace elements in muscles of some commonly available fish in Australia and India.

The levels of trace elements (As, Hg, Cr, Cd, Pb, Co, Ni, Cu, Mn and Zn) in commercially important fish species sampled from fish markets of Adelaide, Australia; canned fish from South Australian supermarkets; and fish markets of West Bengal, India were determined by inductively coupled plasma mass spectrometry (ICP-MS) after microwave digestion. Mercury was determined by using triple quadrupole ICP-MS. The accuracy of the methods was assessed with a certified standard reference material (NRCC-DORM-3 dogfish protein), and the results were compared with values reported in the literature. The results indicated considerable variations in the accumulation of trace elements among the fish species. The relationship between species with respect to trace element concentrations was examined using cluster analysis, which showed Indian fish species forming distinct groups from the others. Other than As in sardines, whiting and snapper and Hg in swordfish and snapper, the trace element concentrations were within permissible limits recommended by various standards. Based on the estimated daily intake (EDI), fish samples analysed in this study can be considered safe for human consumption as per the recommended daily dietary allowance limit fixed by various agencies. Continuous monitoring and assessments of fish metal(loid) content are needed to generate more data and safeguard human health.

A baseline study on trace metals concentration and its ecological risk assessment from the coast of South Andaman Island, India

The rapid urbanization processes in island coastal areas has led to serious pollution in the marine environment. Less is known about the trace metal speciation and ecological risk (ER) in the coastal sediments of island areas under various human activities pressures, which is essential to address the connection between metal pollution and anthropogenic impacts. We report here the trace metals concentration and its ecological risk on the coast of South Andaman Island (SAI). A total of 23 study locations were selected (March 2013) and the surface sediments were studied for trace metal concentrations such as Iron (Fe), Manganese (Mn), Chromium (Cr), Cobalt (Co), Copper (Cu), Nickel (Ni), Arsenic (As), Zinc (Zn), and Lead (Pb). Moreover, the marine pollution indices such as Enrichment Factors (EFs), Geo-accumulation Index (Igeo), Contamination Factor (CF), Pollution Load Index (PLI), and Sediment Pollution Index (SPI) were also studied to consider the spatial distribution of trace metals. The concentration values of trace elements are found in the order of Fe > Mn > Cr > Ni > Zn > Cu > Co > Pb > As. The CF analysis suggested that the South Andaman coastal sediments are a relatively significant level of elements contamination. Besides the EF and Igeo values also showed significant enrichment in the nearby settlement area and indicated that the study locations are coming under unpolluted and moderately polluted categories. The PLI and SPI analyses showed that the inner Bay region (stations 1, 2, 3, and 20) of Port Blair Bay is a highly polluted area and its ER values suggest that the sediments fall under the moderate risk (69.56%) and considerable risk (30.43%) categories. The statistical analysis clearly indicated that the accumulations of trace elements in the study locations are due to anthropogenic inputs from the adjacent land-based sources. Spatial data on the heavy metal concentration of the studied site would help the policymaker/environmental managers to identify the vulnerability site and take appropriate remedial effort to protect the pristine island coastal ecosystem.

Variation in morphological and chemical traits of Mediterranean tree roots: linkage with leaf traits and soil conditions

AimsRoot functions are multiple and essential for the growth and survival of terrestrial plants. The aim of this work was to analyse the main trends in the variation of root traits, their coordination with leaf traits and their relationships with soil conditions.MethodsWe measured the variation of 27 fine root traits (five morphological, 20 chemical and two isotopic signatures) in trees of seven species of a mixed plantation in a metal-contaminated and remediated site of Southern Spain.ResultsWe found evidences supporting the existence of a root economics spectrum (RES). However, other dimensions were identified as being independent of the main RES: mainly the variation in the carbon concentration, the accumulation of trace elements associated with tolerance of metal-rich soils, and the fractionation of δ15N as a time-integrated trait of mycorrhizal-mediated nutrition. In general, roots and leaves were functionally coordinated, although most of the trace elements showed strong root-leaf discordance. The soil conditions interacted with the fine root traits in feedback processes. The ability of tree roots to accumulate trace elements and to reduce their translocation to leaves is a desirable trait for the phytoremediation of metal-contaminated soils.ConclusionsRoots are multifunctional. Understanding the variations in the root traits of trees will help us to predict both the responses of forests to global changes, including soil contamination, and the provision of soil-based ecosystem services.

Trace element fractionation through halite crystallisation: Geochemical mechanisms and environmental implications

Halite is an important mineral for industry, agriculture and food production. It crystallises during water evaporation, and the progressive increase of dissolved metal ions in the brine occurs simultaneously. Thus, halite exploitation may deliver metal ions into the environment and the mechanism of this trace element accumulation has to be studied. In this work, we investigate the distribution of lanthanides and Y (hereafter called rare earth elements, REE), Zr and Hf between crystallising halite and brines in the Dead Sea as geochemical tools for recognising the mechanism of metal ion removal from brines and accumulation in halite. Halite forms cubic crystals where octahedral planes sometimes occur under particular thermal gradient conditions. Our findings indicate that crystal morphology influences the mechanism of metal ion removal from brines because octahedral surfaces are polar unlike those that are cubic. Accordingly, octahedra preferentially fractionate aqueous charged species such as [Hf(OH)5]−, compared to neutral species such as [Zr(OH)4]0. Cubic surfaces do not fractionate aqueous species. In crystal cores, positive Eu anomalies occur suggesting Eu substitution for Na in the lattice. This substitution is energetically justified by ab initio calculations. Hf enrichment relative to Zr also occurs in primary halite-rich evaporites. It is not found in cubic halite from saltworks. The results of this study suggest that primary halite kinetically crystallised from brines can concentrate dissolved metal ions onto crystal surfaces where dissolved charged species are adsorbed. Accordingly, the dissolution of halite due to human activity can release these metal ions to the environment.

Health risk assessment and potentiality of green seaweeds on bioaccumulation of trace elements along the Palk Bay coast, Southeastern India

Bioaccumulation of metals in ten species of green seaweeds collected along the Palk Bay was assessed in the present study. The accumulation of metals in all the ten species were in the order of Pb > Cu > Zn > Cd. Cd was recorded above the permissible level, and Pb, Cu and Zn were below the permissible level of CEQG. The metal concentration in seaweeds was above the WHO standards. The permissible levels of metals were compared with the standards of human health risk assessment, which shows that the exposure of metals from seaweeds has moderate hazard risk to humans. The result of trace element accumulation in four seasons was in the order of summer >monsoon>pre-monsoon>post monsoon. One-way ANOVA revealed that Cd and Pb show significant differences (p˂0.01) in all the species. Cu showed significant variation (p˂0.01) in all the four seasons. Zn also showed significant difference (p˂0.01) during pre-monsoon season.

Quantifying influences of interacting anthropogenic-natural factors on trace element accumulation and pollution risk in karst soil

This study quantified influences of interactions between anthropogenic and natural factors on trace element accumulation and pollution risk in karst soils at regional and local scales and identified the dominant interacting factors. A total of 513 soil samples were collected from Hechi, southern China to measure concentrations of arsenic (As), cadmium (Cd), chromium (Cr), mercury (Hg), and lead (Pb), which were compared with published background values. Descriptive statistics and occurrence characteristics were developed with geostatistical methods and the comprehensive pollution risk was calculated using the Nemerow pollution index (NPI). Geo-detector models were used to further examine and quantify the influence of 14 factors (5 anthropogenic and 9 natural) on trace element concentrations and NPI, both individually and interacting with the other 13 factors. The results clearly demonstrate that anthropogenic factors interact with natural factors to enhance nonlinearly and significantly trace element accumulation in karst soils. Watershed was the natural factor that most enhanced trace element accumulation when interacting with anthropogenic factors. Land use and smelting industry were the anthropogenic factors that most enhanced trace element accumulation when interacting with natural factors. Land use-watershed interaction accounted for 56% of Cd accumulation and smelting industry-watershed interaction for 19% of As accumulation. Land use-watershed, land use-lithology, and pH-watershed interactions accounted for 51%, 19%, and 15%, respectively of NPI values. The findings indicate that changing land use and reducing pollutant discharge from the smelting industry should be considered.