Hazardous Trace Metals Research Articles

Alleviation of heavy metals chromium, cadmium and lead and plant growth promotion in Vigna radiata L. plant using isolated Pseudomonas geniculata.

Plants exposed to heavy metals (HMs) stress negatively affect their development and production capacity. Chromium (Cr), Cadmium (Cd), and Lead (Pb) are the most common hazardous trace metals in agriculture. The physiological, biochemical, and molecular characteristics of crops are being affected. Phytoremediation is a method to alleviate heavy metals from the contaminated soil. The study aims to evaluate the phytoremediation ability of Vigna radiata L. (mung bean) in the absence and the presence of multi-metal tolerant and plant growth promoting Pseudomonas geniculata strain TIU16A3 isolated from soil of tannery industrial estate, Kolkata, West Bengal, India. The strain was further assessed with increasing concentrations of Cr, Cd, and Pb (10, 20, 40, and 80µg/mL) when the mung bean plant was a test crop. The strain significantly increased plant growth, chlorophyll content, increased level of antioxidant enzymes such as superoxide dismutase, peroxidase, and catalase, and decreased oxidative stress indicators like H2O2 and electrolyte leakage in the presence of Cr, Cd, and Pb as compared to plants grown in the absence of Pseudomonas geniculata strain. Shoot length responsive gene (Aux/IAA) in the presence of heavy metal alone and Pseudomonas geniculata treated Cd and Cr showed higher relative expression of (Aux/IAA) compared to Pb. Due to these intrinsic abilities, Pseudomonas geniculata strain TIU16A3 can be a plant growth promoter and thus can help in the remediation of heavy metal (Cr, Cd, and Pb) contaminated soil.

Sediment-bound hazardous trace metals(oid) in south-eastern drainage system of Bangladesh: First assessment on human health

Despite the beneficial aspect of a natural drainage system, increasing human-induced activities, which include urbanization and growth in industrialization, degrade the ecosystem in terms of trace metal contamination. In response, given the great importance of the south-eastern drainage system in Bangladesh, a detailed evaluation of the human health risk as well as the potential ecological risk of trace metals (Be, Cd, Co, Cr, Cu, Hg, Ni, Pb, Se, V, Zn, and As) in Karnaphuli riverbed sediment was conducted. Mean levels of the elements in mg/kg were As (5.62 ± 1.47); Se (0.84 ± 0.61); Hg (0.37 ± 0.23); Be (1.17 ± 0.49); Pb (15.62 ± 8.42); Cd (0.24 ± 0.33); Co (11.59 ± 4.49); Cr (112.75 ± 40.09); Cu (192.67 ± 49.71); V (27.49 ± 10.95); Zn (366.83 ± 62.82); Ni (75.83 ± 25.87). Pollution indicators, specifically contamination factor (CF), pollution load index (PLI), degree of contamination (Cd), enrichment factor (EF), geo-accumulation index (Igeo), and potential ecological risk index (RI), were computed to assess sediment quality. For the first observation of health risk, chronic daily intake (CDI), hazard quotient (HQ), hazard index (HI), carcinogenic risk (CR) and total carcinogenic risk (TCR) indices were calculated. According to the results, CDI values through the ingestion route of both the adult and child groups were organized in the following descending mode respectively: Zn > Cu > Cr > Ni > V > Pb > Co > As > Se > Be > Cd > Hg. The non-carcinogenic risks were generally low for all routes of exposure, except HQingestion was slightly higher for both adults and children. The calculated hazard index (HI) was, nevertheless, within the permitted range (HI < 1). Similarly, none of the metals exhibited any carcinogenic risks, as all CR values were within the 10−4-10−6 range. The need for authoritative efforts and water policy for the sake of the surrounding ecosystem and human health in the vicinity of the examined watershed is strongly felt as an outcome of this study. The purpose of this study is to protect public health by identifying trace metal sources and reducing industrial and domestic discharge into this natural drainage system.

Main chemical and mineralogical components of the Rio Doce sediments and the iron ore tailing from the Fundão Dam disaster, Southeastern Brazil

Since the Fundão Dam rupture in Southeastern Brazil caused an enormous amount of iron ore tailing (IOT) to be discharged into the Doce River Catchment, various works have been published on the soil, water, and biota contamination by potentially hazardous trace metals. However, the objective of this study is to investigate changes in the main chemical composition and the mineral phases, which has not been studied yet. We present an analysis of sediment samples collected in the Doce River alluvial plain, before and after the disaster, as well as the tailing deposited. Granulometry, main chemical composition by X-ray fluorescence spectrometry, mineralogy by X-ray diffractometry, quantification of mineral phases using the Rietveld method, and scanning electron microscope imaging are shown. We conclude that the Fundão Dam rupture introduced fine particles into the Doce River alluvial plain, increasing the Fe and Al content in the sediments. The high Fe, Al, and Mn contents in the finer iron ore tailing fractions represent environmental risks for soil, water, and biotic chains. The IOT mineralogical components, mainly the muscovite, kaolinite, and hematite present in the finer particles can increase the sorption and desorption capacity of harmful trace metals depending on the natural or induced redox conditions, which are not always predictable and avoidable in the environment.

Is there any direct link between hazardous trace metals and the allantoin content in some moss species?

The accumulation of allantoin and trace metals (TMs) in nine moss species was examined after the exposure to stress conditions. Both the environmental anthropopressure effect and laboratory-simulated stress conditions were monitored. Moss samples were collected from different locations, i.e. a non-TM contaminated area, an urban area, and a metalliferous area. The effect of Cd, Pb, Hg, Ni, Zn, salinity, and an acidic environment on the allantoin content was tested. Principal component analysis was performed to reveal the relationship between samples of different origin. Large differences in the metal and allantoin accumulation capability of mosses were noted between samples harvested from the different locations. Seven species were considered as potential metal accumulators, as they exhibited tolerance to elevated levels of heavy metals. The observed TM effect on the allantoin accumulation indicated TM pollution as an important environmental factor that can significantly influence the content of this compound in mosses. Further studies on the contribution of various environmental factors and individual characteristics of plant species are highly expected to recognize the trend in the accumulation of specialized metabolites and TMs in response to hazardous growth conditions.

Speciation of Cu, Cd, Pb and Zn in a contaminated harbor and comparison to environmental quality standards

The water column of harbors contains significant amounts of (priority) hazardous trace metals that may be released into coastal areas of high societal and economic interests where they may disturb their fragile equilibria. To deepen our understanding of the processes that influence the transport of the various metal fractions and allow for a more rigorous environmental risk assessment, it is important to spatially monitor the relevant chemical speciation of these metals. It is of particular interest to assess their so-called dynamic fraction, which comprises the dissolved chemical forms that are potentially bioavailable to living organisms. In this study this was achieved in the Genoa Harbor (NW Italy) for copper (Cu), lead (Pb), cadmium (Cd) and zinc (Zn) by applying a multi-method approach. For the first time in this system the dynamic fractions of the target metals (CuDyn, CdDyn, PbDyn, ZnDyn) were observed in real-time on-board by voltammetry using innovative electrochemical sensing devices. Trace metals in the operationally defined dissolved <0.2μm and <0.02μm fractions were equally quantified through sampling/laboratory-based techniques. The obtained results showed a clear spatial trend for all studied metals from the enclosed contaminated part of the harbor towards the open part. The highest CuDyn and CdDyn fractions were found in the inner part of the harbor while the highest PbDyn fraction was found in the open part. The proportion of ZnDyn was negligible in the sampled area. Small and coarse colloids were involved in Cu, Cd and Zn partitioning while only coarse colloids played an important role in Pb partitioning. The determined concentrations were compared to the Environmental Quality Standards (EQS) established by the EU and those determined by the Australia and New Zealand to trigger for 99 and 95% species protection values. The results of this work allow us to highlight gaps in the EQS for which metal concentration thresholds are excessively high or non-existent and should urgently be revised. They also reflect the need to quantify the potentially bioavailable fraction of hazardous trace metals instead of just their total dissolved concentrations. The data support the establishment of environmental quality standards and guidelines based on realistic risk assessment to protect aquatic life and resources and ultimately human health.

Evaluation of concentrations of trace metal(loid)s in indigenous crab species and human health risk implications

Despite the nutritional benefits of crab consumption, the bioaccumulation of hazardous trace metals (loid) in crabs can endanger consumers’ health. The consumption of crab has received less attention. As, Cd, Cr, Cu, Li, Hg, Fe, Pb and Zn in four common crab species collected from the bank of selected streams and the associated health risks were analyzed for the consumers by evaluating estimated weekly intake (EWI), non-carcinogenic and carcinogenic health risks to children, adolescents, and adults. In this study, 320 samples were collected in total. These crab and sediment samples showed a descending average content of Fe > Zn > Cu > Cr > Pb > As > Cd > Li > Hg, respectively. EWI values of children, adolescents, and adults were all lower than provisional tolerable weekly intakes (PTWIs) of all crab species. According to the toxic hazard quotient (THQ) and the total hazard index (HI) calculations for trace metal contents in the crabs, mercury did not pose any risk to human health; whereas, the other determined trace metals (loid) gave the values of HI > 1 and showed a possibility of risk on the long term. In all age groups, the consumption of U. tangeri, O. Africana, and C. armatum would lead to lifetime cancer risk due to As and Cd bioaccumulation. Also, Statistical analysis reveals the origin of the contaminants in the crabs, and indicate that Cr, Zn, Pb, and Cd are from anthropogenic activities while the other metals originate from natural lithogenic actions.

Sauaeda Fruticusa is Hyperaccumulator of Chromium and Lead

Sauaeda Fruticusa is Hyperaccumulator of Chromium and Lead

Coal beneficiation technology to reduce hazardous heavy metals in fly ash

Fly ash emitted from the coal-fired power plant is the major contributor of the outdoor airborne particulate matters (PMs). Coal beneficiation, an industrial process to improve the quality of raw coal by removing ash-bearing components, can be a cost-effective sustainable and clean technology to reduce the emission of hazardous trace metals. As the removal efficiency of mineral matters and heavy metals within the coal is depend highly on the raw coal and the employed beneficiation process, a wide range of case studies at laboratory- and industrial-scale, published in the last 20 years, are reviewed in this study. Our review indicates that the coal beneficiation processes can effectively reduce content of heavy metals of fly ash, encouraging the use of clean coal to reduce pollutants emission.

Hazardous elements in aqueous leachates of coal fly ash around thermal power plants disposal area

The fossils fuels are main resources of energy worldwide. Huge production of coal fly ash creates water and air pollution. Coal fly ash generally contains trace toxic metals like Ni, Hg, As, Cr, Cd, Ba, Mn, and Pb etc., so coal fly ash is considered as an environmental hazard worldwide. These toxic elements leached from coal fly ash into soil and water which contaminate soil, ground water and other water sources. In present paper is the study of water samples collected from different locations near fly ash disposal area. We found that the water samples contain hazardous trace metals in concentration higher than the permissible limits of drinking water standard. Coal fly ash and other constituents which are generated from coal can create harmful effect on environment, society, health and life. A better method is required to disposal of coal fly ash generated from thermal power plant in India to stop contamination of environment as it is a matter of great concern to human health.

Mapping the probability of exceeding environmental quality standards for Cd and Pb concentrations in soil of northern Tarim Basin using Bayesian geostatistical model

Cadmium and Pb are important hazardous trace metals in the biosphere, and they are considered to pose a great threat to environmental health. The probability map exceeding the environmental quality standard (EQS) can be used to measure the uncertainty of the spatial distribution of soil Cd and Pb and provides useful information for decision-making for environmental management. Many researchers have focused on Cd and Pb environmental problems in agricultural soils, and there are few studies that have investigated the Cd and Pb contents exceeding EQS in natural soils of the arid desert areas of northwest China. We collected 150 samples at 0-0.05 m and 0.05-0.1 m depths in the natural solonchak soil of northern Tarim Basin, Xinjiang Province. The average concentrations of Cd and Pb were 0.45 mg/kg and 42.13 mg/kg at 0-0.05 m, and 0.29 mg/kg and 16.88 mg/kg at 0.05-0.1 m, respectively. The soil Cd and Pb concentrations were increased in comparison with the environmental background values. In addition, the soil Cd and Pb concentrations at 0-0.05 m were significantly higher than those at 0.05-0.1 m. We used the Bayesian geostatistical model to predict the spatial distribution of Cd and Pb concentrations and to map the probability of soil Cd and Pb exceeding the EQS. These probability maps are expected to be helpful for soil environmental protection of northern Tarim Basin.

A mechanism for efficient cadmium phytoremediation and high bioethanol production by combined mild chemical pretreatments with desirable rapeseed stalks

Cadmium (Cd) is one of the most hazardous trace metals, and rapeseed is a major oil crop over the world with considerable lignocellulose residues applicable for trace metal phytoremediation and cellulosic ethanol co-production. In this study, we examined that two distinct rapeseed cultivars could accumulate Cd at 72.48 and 43.70 ug/g dry stalk, being the highest Cd accumulation among all major agricultural food crops as previously reported. The Cd accumulation significantly increased pectin deposition as a major factor for trace metal association with lignocellulose. Meanwhile, the Cd-accumulated rapeseed stalks contained much reduced wall polymers (hemicellulose, lignin) and cellulose degree of polymerization, leading to improved lignocellulose enzymatic hydrolysis. Notably, three optimal chemical pretreatments were performed for enhanced biomass enzymatic saccharification and bioethanol production by significantly increasing cellulose accessibility and lignocellulose porosity, along with a complete Cd release for collection and recycling. Hence, this study proposed a mechanism model interpreting why rapeseed stalks are able to accumulate much Cd and how the Cd-accumulated stalks are of enhanced biomass saccharification. It has also provided a powerful technology for both cost-effective Cd phytoremediation and value-added bioethanol co-production with minimum waste release.

Metals Phytotoxicity Assessment and Classification

In this paper, the influence of trace metals(Cd, Pb, Cu, Co, Ni, Zn) on plants of spring barley (Hordeum vulgare L.) was investigated in polluted sod podzolic sandy loam on layered glacial sands and calcareous deep chernozem on loamy loess soils. We propose to estimate the phytotoxicity with help of phytotoxicological classification. The phytotoxicological classification of trace metals gives the possibility to assess their hazard for plants. On the base of indicators such as: plant up-taking index (UI), phytoletal dose (PhLD50), Dipole moment (µ), Phyto Maximum Allowable Concentration (PMAC) a phytotoxicological classification of hazardous trace metals was suggested. The four classes of danger in phytotoxicological classification of hazardous trace metals were offered. According to phytotoxicological classification, Cd, Co, Ni belong to the first class of hazard, Cu – to second class of hazard, Zn – to third class of hazard, Pb – to fourth class of hazard. Phytotoxicological classification of hazardous trace metals gives the possibility to comprehensively estimate the danger of trace metals for plants as a biological object that plays a very important role in the life of ecosystem. This approach may be applied for another trace metals risk assessment for other plants.

Metals Phytotoxicity Assessment and Classification

In this paper, the influence of trace metals(Cd, Pb, Cu, Co, Ni, Zn) on plants of spring barley (Hordeum vulgare L.) was investigated in polluted sod podzolic sandy loam on layered glacial sands and calcareous deep chernozem on loamy loess soils. We propose to estimate the phytotoxicity with help of phytotoxicological classification. The phytotoxicological classification of trace metals gives the possibility to assess their hazard for plants. On the base of indicators such as: plant up-taking index (UI), phytoletal dose (PhLD50), Dipole moment (µ), Phyto Maximum Allowable Concentration (PMAC) a phytotoxicological classification of hazardous trace metals was suggested. The four classes of danger in phytotoxicological classification of hazardous trace metals were offered. According to phytotoxicological classification, Cd, Co, Ni belong to the first class of hazard, Cu – to second class of hazard, Zn – to third class of hazard, Pb – to fourth class of hazard. Phytotoxicological classification of hazardous trace metals gives the possibility to comprehensively estimate the danger of trace metals for plants as a biological object that plays a very important role in the life of ecosystem. This approach may be applied for another trace metals risk assessment for other plants.

Distribution of contaminant trace metals inadvertently provided by phosphorus fertilisers: movement, chemical fractions and mass balances in contrasting acidic soils.

The frequent use of phosphorus (P) fertilisers accompanied by nitrogen and potassium sources may lead to a serious long-term environmental issue because of the presence of potentially hazardous trace metals (TM) in P fertilisers and unknown effects on the TM chemical fractions in agricultural soils. A 16-month-long column experiment was conducted to investigate the mobility and chemical forms of Cd, Cu, Cr, Ni, and Zn introduced into a Mollisol and an Andisol through surface incorporation (0-2cm) of triple superphosphate (TSP) fertiliser. The effects of urea and potassium chloride (KCl) applications were investigated as well. After 15 cycles of 300-mm irrigation, TSP addition increased the 4M HNO3 extractable TM concentration in the upper (0-5cm) section of soils. Beyond this depth, metals showed no significant mobility, with minimal leaching losses (< 1.9%, 25-cm depth). The TM chemical forms in the 0-5cm section were significantly (p < 0.01) affected by the soil type and fertilisers addition. Cadmium, Ni, and Zn were the elements which appeared in a larger proportion (up to 30%) in the most labile fraction (KNO3 extractable) in fertilised soils. The impact of urea depended on the nitrification-related changes in soil pH, while fertilisation with KCl tended to increase the KNO3 fraction of most metals probably due to K+ exchange reactions. Chromium remained minimallyaffected by the urea and KCl applications since this contaminant is strongly bound to the less labile solid phases. The low mobility of TM was governed mainly by their interaction with the solid phases rather than by their speciation at soil pH. The mass balance showed that the geochemical processes underwent in time by the P fertiliser increased the amount of TM extracted by the chemical fractionation scheme, therefore the reaction period of TSP with soil particles should be taken into account for evaluating TM availability. Long-term soil fertilisation could inadvertently contribute to an increased concentration and availability of these P fertilisers-born contaminants in the cultivated layer of acidic soils.

Efficient separation of hazardous trace metals and improvement of the filtration properties of green liquor dregs by a hydrocyclone

Abstract The treatment of green liquor dregs (GLD), the main inorganic solid residues of kraft pulp mills, is a major concern in the industrial scale. In this study, the effect of hydrocyclone classification on the filtration properties of GLD and the separation of hazardous trace metals, such as Cd, Ni, Pb and Zn, rare earth elements, and other trace metals was investigated. The experiments were designed to find the influence of parameters such as the overflow to the underflow outlet diameter ratio and inlet pressure on the separation efficiency of a hydrocyclone. The results showed that a lower total filtration area was required for the separation of underflow and overflow fractions than for the original GLD sludge. Also, hazardous trace metals were effectively separated into finer overflow fractions, enhancing the possibilities to utilize the purified underflows e.g. in fertilizers and soil amendment. By using the diameter ratio of 3.70 and the inlet pressure of 1 bar, 90.1 wt-% of Cd, 70.1 wt-% of Ni and 91.4 wt-% of Zn were separated into the overflow, collecting 30 wt-% of the dregs in this fraction. The concentrations of rare earth elements (REEs) in the underflow solids were lower than the ones in the original sludge. Unlike the trace metals and REEs, Ca was accumulated in coarser particles that were separated by underflow fractions. Therefore, a majority of the dregs, enriched by Ca, was separated by underflow fractions. The possibility of categorizing the underflow fractions in CE-marked fertilizing products was also studied.

Seasonal Variations of Atmospheric Particulate Matter and its Content of Heavy Metals in Klang Valley, Malaysia

The composition of atmospheric particulate matter (PM10) can help to identify its potential sources and possible impact on human health. This study investigates the seasonal variations and sources of heavy metals in PM10 in the Cheras area. PM10 samples were collected on a 24-h basis using a high-volume air sampler in June during the southwest monsoon and in December during the northeast monsoon of 2014. Selected hazardous trace metals, viz., As, Pb, Cu, Ni, Cd, Co, Mn, Zn, Fe, Cr, V and Ba, were measured by inductively coupled plasma mass spectrometry (ICP-MS). The result showed that the mean concentrations of PM10 were 207.63 ± 7.82 and 138.32 ± 4.67 during the southwest and northeast monsoons, respectively. The heavy metal concentrations during the southwest monsoon followed the order Ba > Fe > Cu > V > Zn > Pb > Mn > Cr > As > Ni > Cd > Co, while those during the northeast monsoon followed the order Zn > Fe > Ba > Cu > Pb > V > Cr > As > Mn > Ni > Cd > Co. The results of the enrichment factors (EFs) showed that the major trace metals mainly originated from anthropogenic sources. A correlation analysis indicated that pairs of trace metals from similar sources were suspended in PM10 in the ambient air. The source apportionment by principal component analysis (PCA) and cluster analysis (CA) suggested that vehicle exhaust and brake and tire wear, industrial emissions and the re-suspension of dust, as well as oil combustion, were the most dominant sources of PM10 in this study.

The Effects of Biogeochemical Modification of Fe-Rich Smectite on the Fate of Pb

AbstractFe-rich smectite is ubiquitous in soil environments and closely linked to the fate and mobility of hazardous trace metals and particularly to the variations in the biogeochemical redox reactions of structural Fe that determine the sorption and desorption properties of clay minerals. The biotic/abiotic redox reactions of a Fe-rich smectite, nontronite (NAu-1), were performed at various reaction times using the Fe-reducing bacterium Shewanella oneidensis MR-1 at 30°C and Na-dithionite (Na2S2O4), respectively. The extent of biotic Fe-reduction of NAu-1 after 30 days of incubation reached up to 10.7% of total Fe and the range of abiotic Fe-reduction varied from 4.9–46.6% at reaction times of 5 min, 30 min, 1 h, and 4 h. The biotically and abiotically Fe-reduced NAu-1 samples were spiked with Pb concentrations of 0.07, 0.2, 0.5, and 1.0 mg/kg and incubated under aerobic or anaerobic conditions for 24 h.The amounts of Pb in the supernatants were analyzed using an Inductively Coupled Plasma Mass Spectrometer (ICP-MS) and Multi-collector (MC)-ICP-MS. The amounts of Pb removed from the supernatants were negatively related to the extent of Fe(III) reduction in the abiotically Fe-reduced NAu-1 samples. In contrast, less Pb (~15%) was removed from the biotically Fe-reduced NAu-1 samples with a similar extent of Fe(III) reduction. Changes in the isotopic 208/204Pb ratio indicated that the lighter 204Pb isotope was preferentially adsorbed to the NAu-1 samples with less Fe reduction and indicated that variations in the net layer charge affected isotopic fractionation. Significant differences in the 208/204Pb ratios for NAu-1 samples that were biotically Fe-reduced under anaerobic conditions were measured and indicate that the reversibility of the structural/chemical modifications that occur under redox conditions can affect Pb removal and, thus, isotope fractionation. These results collectively infer that the biogeochemical properties of clay minerals should be considered in order to understand the fate of trace metals in natural environments.

Effective removal of hazardous trace metals from recovery boiler fly ashes

The objective of this study is to introduce a treatment sequence enabling straightforward and effective recovery of hazardous trace elements from recovery boiler fly ash (RBFA) by a novel method, and to demonstrate the subsequent removal of Cl and K with the existing crystallization technology. The treatment sequence comprises two stages: dissolution of most other RBFA components than the hazardous trace elements in water in Step 1 of the treatment, and crystallization of the process chemicals in Step 2. Solid-liquid separation has an important role in the treatment, due to the need to separate first the small solid residue containing the trace elements, and to separate the valuable crystals, containing Na and S, from the liquid rich in Cl and K. According to the results, nearly complete recovery of cadmium, lead and zinc can be reached even without pH adjustment. Some other metals, such as Mg and Mn, are removed together with the hazardous metals. Regarding the removal of Cl and K from the process, in this non-optimized case the removal efficiency was satisfactory: 60–70% for K when 80% of sodium was recovered, and close to 70% for Cl when 80% of sulfate was recovered.

Effects of anthropogenic activities in a Mediterranean coastland: the case study of the Falerno-Domitio littoral in Campania, Tyrrhenian Sea (southern Italy)

The environmental status of the Falerno-Domitio littoral, a sector of the Italian south coast (Campania region) locally affected by an extensive anthropic pressure and pollution, was assessed by a multi-disciplinary approach, consisting of geological vs. biological studies. Geochemical abundance of potentially hazardous trace metals in beach sands is mainly constrained by the nature of the source rocks. Geochemical data of marine sediment quality with regards to possible heavy metal pollution and the enrichment factors of selected potentially toxic metals show that Cr and V values are higher in marine samples than in natural sources, suggesting that they are, at least in part, of anthropic derivation. A relationship between meiobenthos and heavy metals (Cr, Co, and V) has been also observed, providing a valuable biological marker to human-deriving chemical pollution. Ecotoxicological analyses confirm a relationship between enrichment in selected metals and moderate toxicity of some sea-bottom sediments closer to the coastline.

Pectinous cell wall thickenings formation – A common defense strategy of plants to cope with Pb

Lead, one of the most abundant and hazardous trace metals affecting living organisms, has been commonly detected in plant cell walls including some tolerant plants, mining ecotypes and hyperaccumulators. We have previously shown that in tip growing Funaria sp. protonemata cell wall is remodeled in response to lead by formation of thickenings rich in low-methylesterified pectins (pectin epitope JIM5 - JIM5-P) able to bind metal ions, which accumulate large amounts of Pb. Hence, it leads to the increase of cell wall capacity for Pb compartmentalization.Here we show that diverse plant species belonging to different phyla (Arabidopsis, hybrid aspen, star duckweed), form similar cell wall thickenings in response to Pb. These thickenings are formed in tip growing cells such as the root hairs, and in diffuse growing cells such as meristematic and root cap columella cells of root apices in hybrid aspen and Arabidopsis and in mesophyll cells in star duckweed fronds. Notably, all analyzed cell wall thickenings were abundant in JIM5-P and accumulated high amounts of Pb. In addition, the co-localization of JIM5-P and Pb commonly occurred in these cells. Hence, cell wall thickenings formed the extra compartment for Pb accumulation. In this way plant cells increased cell wall capacity for compartmentalization of this toxic metal, protecting protoplast from its toxicity.As cell wall thickenings occurred in diverse plant species and cell types differing in the type of growth we may conclude that pectinous cell wall thickenings formation is a widespread defense strategy of plants to cope with Pb. Moreover, detection of natural defense strategy, increasing plant cell walls capacity for metal accumulation, reveals a promising direction for enhancing plant efficiency in phytoremediation.