Effects of citric acid on arsenic transformation and microbial communities in different paddy soils.

Root exudate is a major source of soil organic matter and can significantly affect arsenic (As) migration and transformation in paddy soils. Citric acid is the main component of rice root exudate, however, the impacts and rules of citric acid on As bioavailability and rhizobacteria in different soils remains unclear. This study investigated the effects of citric acid on As transformation and microbial community in ten different paddy soils by flooded soil culture experiments. The results showed that citric acid addition increased total As and arsenate (As(V)) in the soil porewater by up to 41-fold and 65-fold, respectively, after 2-h incubation. As(V) was the main As species in soil porewater within 10 days with the addition of citric acid. Non-specifically sorbed As of soils, total Fe and total As were the main environmental factors affecting the soil microbial communities. High-throughput sequencing analysis demonstrated that citric acid addition significantly altered the soil microbial community structure, shifting the Proteobacteria-related reducing bacteria to Firmicutes-related reducing bacteria in different paddy soils. The relative abundance of Firmicutes was promoted by 174-196%. Clostridium-related bacteria belonging to Firmicutes became the dominant genera, which is believed to regulate As release through the reductive dissolution of iron oxides or the direct reduction of As(V) to arsenite (As(III)). However, citric acid addition significantly decreased the relative abundance of Geobacter and Anaeromyxobacter, which are also typical active As(V)- and ferric-reducing bacteria. Real-time quantitative polymerase chain reaction (qPCR) also revealed that the addition of citric acid significantly decreased the relative abundances of Geobacter in the different soils by 8-28 times while the relative abundances of Clostridium increased by 2-5 times. These results provide significant insight on As transformation in different types of rice rhizospheric soils and guidance for the application of rice varieties with low citric acid exuding to restrict As accumulation.

Cadmium reduced methane emissions by stimulating methane oxidation in paddy soils.

Flooded rice paddy fields are a significant source of anthropogenic methane (CH4) emissions. Cadmium (Cd) is one of the most common and toxic contaminants in paddy soils. However, little is known about how the soil microbial communities associated with CH4 emissions respond to the increasing Cd-stress in paddies. In this study, we employed isotopically 13C-labelled CH4, high-throughput sequencing analysis, and gene quantification analysis to reveal the effect and mechanism of Cd on CH4 emissions in paddy soils. Results showed that 4.0 mg kg-1 Cd addition reduced CH4 emissions by 16-99% in the four tested paddy soils, and significantly promoted the transformation of 13CH4 to 13CO2. Quantitative polymerase chain reaction (qPCR) demonstrated that Cd addition increased the abundances of pmoA gene, the ratios of methanogens to methanotrophs (mcrA/pmoA) showed a positive correlation with CH4 emissions (R2 = 0.798, p < 0.01). Furthermore, the composition of the microbial community containing the pmoA gene was barely affected by Cd addition (p > 0.05). This observation was consistent with the findings of a pure incubation experiment where methanotrophs exhibited high tolerance to Cd. We argue that microbial feedback to Cd stress amplifies the contribution of methanotrophs to CH4 oxidation in rice fields through the complex interactions occurring among soil microbes. Our study highlights the overlooked association between Cd and CH4 dynamics, offering a better understanding of the role of rice paddies in global CH4 cycling.

Sustainable Immobilization of Arsenic by Man-Made Aerenchymatous Tissues in Paddy Soil.

Arsenic (As) is a major environmental pollutant and poses a significant health risk to humans through rice consumption. Elevating the soil redox potential (Eh) has been shown to reduce As bioavailability and decrease As accumulation in rice grains. However, sustainable methods for managing the Eh of rice paddies are lacking. To address this issue, we propose a new approach that uses man-made aerenchymatous tissues (MAT) to increase soil Eh by mimicking O2 release from wet plant roots. Our study demonstrated that the MAT method sustainably increased the soil Eh levels from -119 to -80.7 mV (∼30%), over approximately 100 days and within a radius of around 5 cm from the surface of the MAT. Moreover, it resulted in a significant reduction (-28.5% to -63.3%) in dissolved organic carbon, Fe, Mn, and As concentrations. MAT-induced Fe(III) (oxyhydr)oxide minerals served as additional adsorption sites for dissolved As in soil porewater. Furthermore, MAT promoted the oxidation of arsenite to the less mobile arsenate by significantly enhancing the relative abundance of the aioA gene (130% increase in the 0-5 cm soil zone around MAT). The decrease in As bioavailability significantly reduced As accumulation in rice grains (-30.0%). This work offers a low-cost and sustainable method for mitigating As release in rice paddies by addressing the issue of soil Eh management.

Root exudates increased arsenic mobility and altered microbial community in paddy soils.

Root exudates are crucial for plants returning organic matter to soils, which is assumed to be a major source of carbon for the soil microbial community. This study investigated the influence of root exudates on the fate of arsenic (As) with a lab simulation experiment. Our findings suggested that root exudates had a dose effect on the soil physicochemical properties, As speciation transformation and the microbial community structure at different concentrations. The addition of root exudates increased the soil pH while decreased the soil redox potential (Eh). These changes in the soil pH and Eh increased As and ferrous (Fe(II)) concentrations in soil porewater. Results showed that 40 mg/L exudates addition significantly increased arsenite (As(III)) and arsenate (As(V)) by 541 and 10 times respectively within 30 days in soil porewater. The relative abundance of Fe(III)-reducing bacteria Geobacter and Anaeromyxobacter increased with the addition of root exudates, which enhanced microbial Fe reduction. Together these results suggest that investigating how root exudates affect the mobility and transformation of As in paddy soils is helpful to systematically understand the biogeochemical cycle of As in soil-rice system, which is of great significance for reducing the health risk of soil As contamination.

Phenotype and metabolism alterations in PCB-degrading Rhodococcus biphenylivorans TG9T under acid stress.

Environmental acidification impairs microorganism diversity and their functions on substance transformation. Rhodococcus is a ubiquitously distributed genus for contaminant detoxification in the environment, and it can also adapt a certain range of pH. This work interpreted the acid responses from both phenotype and metabolism in strain Rhodococcus biphenylivorans TG9T (TG9) induced at pH 3. The phenotype alterations were described with the number of culturable and viable cells, intracellular ATP concentrations, cell shape and entocyte, degradation efficiency of polychlorinated biphenyl (PCB) 31 and biphenyl. The number of culturable cells maintained rather stable within the first 10 days, even though the other phenotypes had noticeable alterations, indicating that TG9 possesses certain capacities to survive under acid stress. The metabolism responses were interpreted based on transcription analyses with four treatments including log phase (LP), acid-induced (PER), early recovery after removing acid (RE) and later recovery (REL). With the overview on the expression regulations among the 4 treatments, the RE sample presented more upregulated and less downregulated genes, suggesting that its metabolism was somehow more active after recovering from acid stress. In addition, the response mechanism was interpreted on 10 individual metabolism pathways mainly covering protein modification, antioxidation, antipermeability, H+ consumption, neutralization and extrusion. Furthermore, the transcription variations were verified with RT-qPCR on 8 genes with 24-hr, 48-hr and 72-hr acid treatment. Taken together, TG9 possesses comprehensive metabolism strategies defending against acid stress. Consequently, a model was built to provide an integrate insight to understand the acid resistance/tolerance metabolisms in microorganisms.

pH dependence of arsenic speciation in paddy soils: The role of distinct methanotrophs.

Arsenic (As) is a priority environmental pollutant in paddy field. The coupling of arsenate (As(V)) reduction with anaerobic methane (CH4) oxidation was recently demonstrated in paddy soils and has been suggested to serve as a critical driver for As transformation and mobilization. However, whether As(V)-dependent CH4 oxidation is driven by distinct methanotrophs under different pH conditions remains unclear. Here, we investigated the response of As(V)-dependent CH4 oxidation to pH shifts (pH 5.5-8.0) by employing isotopically labelled CH4. Furthermore, the underlying mechanisms were also investigated in well-controlled anoxic soil suspension incubations. Our results showed that As(V)-dependent CH4 oxidation is highly sensitive to pH changes (1.6-6.8 times variation of arsenite formation). A short-term (0-10 d) pH shift from near-neutral pH to acidic conditions (i.e., pH 5.5, -85% arsenite formation) had an inhibitory effect on As(V)-dependent CH4 oxidation. However, prolonged acidic conditions (i.e., >15 d) had no significant influence on As(V)-dependent CH4 oxidation. The microbial analyses indicated that As reduction in paddies can be driven by anaerobic CH4 oxidation archaea (ANME) and methanotrophs. And, methanotrophs may serve as a critical driver for As(V)-dependent CH4 oxidation. Moreover, type I methanotrophs Methylobacter were more active in oxidizing CH4 than type II methanotrophs Methylocystis when the pH ≥ 6.5. However, Methylocystis had a higher tolerance to soil acidification than Methylobacter. This study illustrates that As(V)-dependent CH4 oxidation could be dominated by distinct methanotrophs along with pH shifts, which eventually enhances As release in paddy soils.

Anaerobic methane oxidation coupled to arsenate reduction in paddy soils: Insights from laboratory and field studies.

Anaerobic methane oxidation (AOM) coupled to nitrate, sulfate and iron has been most extensively studied. Recently, AOM coupled with arsenate reduction (AOM-AsR) was demonstrated in laboratory microcosm incubation, however whether AOM-AsR is active in the field conditions remains elusive. Here, we used 13C-labeled methane (13CH4) to investigate the AOM-AsR process in both anaerobic microcosms and field conditions with identical soils. Our results revealed the occurrence of AOM-AsR in the field, but AOM-AsR in the field was not as active as that which occurred in the laboratory (AOM-AsR contributed approximately 33.87% and 80.76% of total As release in the field and laboratory studies, respectively). This occurred because the laboratory setting provided a more suitable condition for the AOM-AsR process. Moreover, the results suggested that the relative abundance of mcrA from the ANME-2d was the most abundant. Our results clearly demonstrate that the AOM-AsR is active in both the laboratory and field conditions. Moreover, the results highlight the potential risk the AOM-AsR for pose for As contamination in rice paddies.

Synchronous response of arsenic methylation and methanogenesis in paddy soils with rice straw amendment.

Rice straw (RS) amendment promotes arsenic (As) methylation and methane (CH4) emissions from paddy soils, which can cause straighthead disease and climate warming. Although methanogens have been identified as critical regulators of methylated As concentrations in flooded soils, the mechanism of these microbial groups on As methylation in paddy soils with RS amendment remains unknown. In this study, paddy soil was incubated to test the response in As methylation and methanogenesis in flooded soil with RS amendment. Our results showed that RS amendment increased the accumulation of monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA) whether methanogenesis was inhibited or not. The methanogens in the genera of Methanocella probably played critical role in promoting As methylation in flooded soil with RS amendment. With the RS amendment, inhibition of methanogenesis led to the accumulation MMA and DMA by suppressing DMA demethylation. The demethylation of DMA was driven by methanogens possibly belonging to the genera of Methanobacterium. This study revealed a wealth of methanogens that dominate As methylation with RS amendment. It will provide guidance to RS amendment in As contaminated paddy soil and has important implications for rice quality and global climate change.

Contribution of components in natural soil to Cd and Pb competitive adsorption: Semi-quantitative to quantitative analysis.

Cadmium (Cd) and lead (Pb) are two of the most common elements found in contaminated sites. The behavior of specific metals in the soil may be affected by other metals because of the competition for adsorption sites. In this study, adsorption experiments after chemical extraction, multi-surface models, and advanced spectroscopy technology were jointly used to explain the adsorption mechanism of Cd and Pb and to determine the contribution of each component in the competitive system. The results show that pH is the key factor in determining the contribution of soil components to metal adsorption. Soil organic matter (SOM) is the dominant adsorbent for both Cd and Pb. Clay minerals play an adsorption role at low pH, whereas Fe/Al oxides adsorb metals primarily in the high pH range. Further, the competitive effect of Pb on Cd occurred primarily on SOM rather than on clay minerals. When the Pb concentration increased from 0 to 500 mg/L, the adsorption of Cd on SOM decreased by 132.0 mg/kg, whereas it decreased only by 1.9 mg/kg on clay minerals. Therefore, the competitive effect of Pb on Cd cannot be ignored in soils with high organic matter content.

Iron-based passivator mitigates the coupling process of anaerobic methane oxidation and arsenate reduction in paddy soils.

Arsenic (As) is a toxic metalloid that is ubiquitous in paddy soils, where passivation is the most widely used method for remediating As contamination. Recently, anaerobic methane oxidation coupled with arsenate (As(V)) reduction (AOM-AsR) has been shown to act as a critical driver for As release in paddy fields. However, the effect and mechanism of the passivators on the AOM-AsR process remain unclear. In this study, we incubated arsenate-contaminated paddy soils under anaerobic conditions. Using isotopically labelled methane and different passivators, we found that an iron-based passivator containing calcium sulfate and iron oxide (9:1, m/m) named IBP showed a much better performance than the other passivators. Adding IBP decreased the arsenite (As(III)) concentration in the soil solution by 78% and increased the AOM rate by 55%. Furthermore, we employed high-throughput sequencing and real-time quantitative polymerase chain reaction (qPCR) to investigate the ability of IBP to control As release mediated by AOM-AsR in paddy fields, as well as its underlying mechanism. Our results showed that IBP addition significantly increased anaerobic methanotrophic (ANME) archaea (ANME-2a-c, ANME-2d, and ANME-3) by 91%, and increased the methane-oxidizing bacterium Methylobacter by 262%. Similarly, IBP addition significantly increased the Fe(III) concentration in soil solution by 39% and increased the absolute abundance of Fe(III)-reducing bacteria (Geobacteraceae) by 21 times in soil. Adding IBP may significantly promote AOM coupled with Fe(III) reduction, significantly reducing electron transfer from AOM to As(V) reduction. Hence, IBP may be used as an efficient passivator to remediate As-contaminated soil using an active AOM-AsR process. These results provide a novel insight into controlling soil As release by regulating an active and critical As mobilization pathway in the environment.

Sustainable removal of soil arsenic by naturally-formed iron oxides on plastic tubes.

Arsenic (As) pollution in paddy fields is a major threat to rice safety. Existing As remediation techniques are costly, require external chemical addition and degrade soil properties. Here, we report the use of plastic tubes as a recyclable tool to precisely extract As from contaminated soils. Following insertion into flooded paddy soils, polyethylene tube walls were covered by thin but massive Fe coatings of 76.9-367 mg Fe m-2 in 2 weeks, which adsorbed significant amounts of As. The formation of tube-wall Fe oxides was driven by local Fe-oxidizing bacteria with oxygen produced by oxygenic phototrophs (e.g., Cyanobacteria) or diffused from air through the tube wall. The tubes with As-bound Fe oxides can be easily separated from soil and then washed and reused. We tested the As removal efficiency in a pot experiment to remove As from ~ 20 cm depth/40 kg soils in a 2-year experiment and achieved an overall removal efficiency of 152 mg As m-2 soil year-1, comparable to phytoremediation with the As hyperaccumulator Pteris vittata. The cost of Fe hooks was estimated at 8325 RMB ha-1 year-1, and the profit of growing rice (around 16080 RMB ha-1 year-1 can be still maintained. The As accumulated in rice tissues was markedly decreased in the treatment (>11.1 %). This work provides a low-cost and sustainable soil remediation method for the targeted removal of As from soils and a useful tool for the study and management of the biogeochemical Fe cycle in paddy soils.

Coupled Aerobic Methane Oxidation and Arsenate Reduction Contributes to Soil-Arsenic Mobilization in Agricultural Fields.

Microbial oxidation of organic compounds can promote arsenic release by reducing soil-associated arsenate to the more mobile form arsenite. While anaerobic oxidation of methane has been demonstrated to reduce arsenate, it remains elusive whether and to what extent aerobic methane oxidation (aeMO) can contribute to reductive arsenic mobilization. To fill this knowledge gap, we performed incubations of both microbial laboratory cultures and soil samples from arsenic-contaminated agricultural fields in China. Incubations with laboratory cultures showed that aeMO could couple to arsenate reduction, wherein the former bioprocess was carried out by aerobic methanotrophs and the latter by a non-methanotrophic bacterium belonging to a novel and uncultivated representative of Burkholderiaceae. Metagenomic analyses combined with metabolite measurements suggested that formate served as the interspecies electron carrier linking aeMO to arsenate reduction. Such coupled bioprocesses also take place in the real world, supported by a similar stoichiometry and gene activity in the incubations with natural paddy soils, and contribute up to 76.2% of soil-arsenic mobilization into pore waters in the top layer of the soils where oxygen was present. Overall, this study reveals a previously overlooked yet significant contribution of aeMO to reductive arsenic mobilization.

Arsenic and cadmium bioavailability to rice (Oryza sativa L.) plant in paddy soil: Influence of sulfate application.

Arsenic (As) and cadmium (Cd) accumulate easily in rice grains that pose a non-negligible threat to human health worldwide. Sulfur fertilizer has been shown to affect the mobilization of As and Cd in paddy soil, but the effect of co-contamination by As and Cd has not been explored. This study selected three soils co-contaminated with As and Cd from Shangyu (SY), Tongling (TL) and Ma'anshan (MA). Incubation experiments and pot experiments were carried out to explore the effect of sulfate supply (100 mg kg-1) on the bioavailability of As and Cd in soil and the rice growth. The results showed that the exogenous sulfate decreased As concentrations in porewater of SY and TL by 51.1% and 29.2% through forming arsenic-sulfide minerals. The exchangeable Cd in soil also declined by 25.6% and 18.6% and transformed into Fe and Mn oxides-bound Cd. The relative abundance of Desulfotomaculum, Desulfurispora and dsr gene increased remarkably indicated that sulfate addition stimulated the activity of sulfate-reducing bacteria. In MA soil, sulfate addition immobilized Cd but had little effect on As solubility, which was speculated to be related to the high sulfate background of the soil. Further pot experiments showed that sulfate application significantly increased rice tillers, biomass, chlorophyll content in shoots, and decreased electrolyte leakage in root. Finally, sulfate significantly reduced As and Cd in SY rice shoots by 60.2% and 40.8%, respectively, while As decreased by 39.6% in TL rice shoots and Cd decreased by 23.0% in MA rice shoots. These results indicate that the application of sulfate can reduce the bioavailability of As and Cd in the soil-rice system and promote rice growth, and it is possible to reduce the accumulation of As and Cd in rice plants simultaneously.

Silicon enhances abundances of reducing microbes in rhizoplane and decreases arsenite uptake by rice (Oryza sativa L.).

Although silicon (Si) transporters-mediated uptake of arsenic (As) by rice roots is well-documented, how Si influences As behaviors in rhizosphere and rhizoplane before As entry into roots is still unclear. Here we used three rice genotypes to explore the effect of silicic acid on the root uptake of As as impacted by chemical and microbial changes in bulk soil, rhizosphere, rhizoplane and endosphere. The results show that exogenous Si decreased root arsenite [As(III)] absorption, which was attributed to Si-mediated alteration of traits in chemical plaque and microbial films on the rhizoplane. The pH, Eh, As and Fe in the porewater were not influenced by Si. However, Si enhanced the concentrations of As(III) (16-49%) and Fe (15-80%) in the rhizoplane while decreasing As(III) concentrations in the roots (19-39%) and grains (22-29%). The diversities and richness of microbes in soils and plants were not affected by Si. The microbial connections were negatively influenced by Si in bulk and rhizosphere soils, but positively impacted in rhizoplane and endosphere. Both the abundance of reducing microbes, Anaeromyxobacter and Geobacteraceae, and the level of As(III) and Fe in rhizoplane were significantly increased by the addition of Si, thereby restraining As(III) from uptake into roots. This study provides new insights into the microbial mechanisms of Si-mediated As uptake by rice.

Removal of Arsenate From Groundwater by Cathode of Bioelectrochemical System Through Microbial Electrosorption, Reduction, and Sulfuration.

Arsenate [As(V)] is a toxic metalloid and has been observed at high concentrations in groundwater globally. In this study, a bioelectrochemical system (BES) was used to efficiently remove As(V) from groundwater, and the mechanisms involved were systematically investigated. Our results showed that As(V) can be efficiently removed in the BES cathode chamber. When a constant cell current of 30 mA (I cell , volume current density = 66.7 A/m3) was applied, 90 ± 3% of total As was removed at neutral pH (7.20-7.50). However, when I cell was absent, the total As in the effluent, mainly As(V), had increased approximately 2-3 times of the As(V) in influent. In the abiotic control reactor, under the same condition, no significant total As or As(V) removal was observed. These results suggest that As(V) removal was mainly ascribed to microbial electrosorption of As(V) in sludge. Moreover, part of As(V) was bioelectrochemically reduced to As(III), and sulfate was also reduced to sulfides [S(-II)] in sludge. The XANES results revealed that the produced As(III) reacted with S(-II) to form As2S3, and the residual As(III) was microbially electroadsorbed in sludge. This BES-based technology requires no organic or chemical additive and has a high As(V) removal efficiency, making it an environment-friendly technique for the remediation of As-contaminated groundwater.

Biochar-supported nanoscale zero-valent iron can simultaneously decrease cadmium and arsenic uptake by rice grains in co-contaminated soil.

Cadmium (Cd) and Arsenic (As) in rice grains are a primary exposure source for human beings. However, the simultaneous stabilization of Cd and As in soil becomes difficult due to the opposite properties of those. In this study, we investigated the simultaneous effects of biochar-supported nanoscale zero-valent iron (nZVI-BC) and water management on the decrease of Cd and As bioaccumulation in rice grain. Compared to the control, 0.25-1.00% nZVI-BC coupled with alternate wetting and drying (AWD) management simultaneously decreased the bioaccumulation of Cd and As in rice grains by 15.85-69.16% and 23.06-59.45%, respectively. The cancer risk associated with rice consumption effectively reduced by 15.60-52.41% after the application of nZVI-BC, and the lowest cancer risk was detected in 1.00% nZVI-BC under AWD management. Furthermore, rice cultivated under AWD management had a lower total cancer risk than that cultivated under continuous flooded (CF) management with the same amendment of type and dose. The reduction of soil Cd and As availability and the formation of iron plaque dominated the decrease of Cd and As uptake by rice grains. The elevated soil pH was responsible for Cd adsorption, and the dominant mechanism for As immobilization was the formation of complexes. The iron plaque was double-edged, promoting and inhibiting Cd uptake by rice, wherein the inhibition was predominant under aerobic conditions. In addition, iron plaque was a barrier to preventing the As accumulation by rice, a larger amount of As was immobilized on the iron plaque with nZVI-BC treatment. This study sheds new insights on the simultaneous remediation of Cd and As co-contaminated paddy fields.

The Effect of Manure Application on Arsenic Mobilization and Methylation in Different Paddy Soils.

Organic matter plays an important role in controlling arsenic(As) release and transformation in soil, however, little is known about the effect of manure application on As behavior in soils with different As contents. In this study, waterlogged incubations using various As-contaminated paddy soils with manure amendment were conducted to investigate how manure application influence As mobilization and methylation in different paddy soils. The results indicated that manure application increased As release in paddy soils with high As (> 30 mg kg-1) contents. Moreover, our findings also showed that manure application increased the relative abundance of arsM-harboring Euryacheota and Planctomycetes at the phylum level and arsM-harbouring Methanocellaceae, Anaerolinea and Bellinea at genus level, thereby promoting As methylation. These results provide important insights for the significant variation in As mobilization and methylation in paddy soils amended with manure. Moreover, our results suggest that serious consideration should be given to the manure application in As-contaminated paddy soil.

The chemical-microbial release and transformation of arsenic induced by citric acid in paddy soil.

Citric acid (CA) is the major exudate of rice roots, yet the effects of CA on arsenic (As) transformation and microbial community in flooded paddy soil have not been clearly elucidated. In this study, microcosms were established by amending CA to As contaminated paddy soils, mimicking the rhizosphere environment. Results showed that 0.5% CA addition significantly enhanced As mobilization after one-hour incubation, increased total As in porewater by about 20-fold. CA addition induced arsenate release into porewater, and subsequently formed ternary complex of As, iron and organic matters, inhibiting further As transformation (including arsenate reduction and arsenite methylation). Furthermore, the results of linear discriminant analysis (LDA) effect size (LEfSe) and network analysis revealed that CA addition significantly enriched bacteria associated with arsenic and iron reductions, such as Clostridium (up to 35-fold) and Desulfitobacterium (up to 4-fold). Our results suggest that CA exhibits robust ability to mobilize As through both chemical and microbial processes, increasing the risk of As accumulation by rice. This study sheds light on our understanding of As mobilization and transformation in rhizosphere soil, potentially providing effective strategies to restrict As accumulation in food crops by screening or cultivating varieties with low CA exuding.

Forty years studies on polychlorinated biphenyls pollution, food safety, health risk, and human health in an e-waste recycling area from Taizhou city, China: a review.

E-waste generation has become a serious environmental challenge worldwide. Taizhou of Zhejiang Province, situated on the southeast coastline of China, has been one of the major e-waste dismantling areas in China for the last 40 years. In this review, we focused on the polychlorinated biphenyl (PCB) trends in environmental compartments, burden and impact to humans, food safety, and health risk assessment from Taizhou, China. The review suggested that PCBs showed dynamic trends in air, soil, water, biodiversity, and sediments. Soils and fish samples indicated higher levels of PCBs than sediments, air, water, and food items. PCB levels decreased in soils with the passage of time. Agriculture soils near the e-waste recycling sites showed more levels of total PCBs than industrial soils and urban soils. Dioxin-like PCB levels were higher in humans near Taizhou, suggesting that e-waste pollution could influence humans. Compared with large-scale plants, simple household workshops contributed more pollution of PCBs to the environment. Pollution index, hazard quotient, and daily intake were higher for PCBs, suggesting Taizhou should be given priority to manage the e-waste pollution. The elevated body burden may have health implications for the next generation. The areas with stricter control measures, strengthened laws and regulations, and more environmentally friendly techniques indicated reduced levels of PCBs. For environment protection and health safety, proper e-waste dismantling techniques, environmentally sound management, awareness, and regular monitoring are very important.