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Understanding the emission characteristics of particulate matter and associated heavy metals is essential for assessing their environmental and health impacts post-emission, as well as for identifying potential control technologies for the sources. Here, a field test was conducted at two advanced smelting plants equipped with comprehensive air pollution control devices. The particles emitted from different stages of lead and zinc smelting exhibited bi-modal size distributions, with peaks observed in PM 0.1–1.0 and PM 2.5–10 , respectively. Particulate-bound Pb was identified as the predominant Pb species in the flue gas, primarily originating from ore crushing. Consequently, over 80 % of Pb was emitted in the form of coarse particles, a marked contrast to coal-fired power plants where Pb concentrated on fine particles. High efficiencies in Pb removal were achieved by dust collectors, flue gas purification systems, and acid plants with desulfurization systems, resulting in overall Pb emission factors in lead and zinc smelting were only 89.3 and 2.60 g t-1 (of metal production), respectively. Importantly, the contribution of gas-phase Pb, which accounts for approximately 16.6 % of total emissions, must not be neglected in future emission monitoring and control efforts. [Display omitted] • Emission factors (EFs) and relative enrichment factors (REFs) for Pb in lead and zinc smelting were updated. • In contrast to coal-fired power plants, more than 80 % of smelting particulate-bound Pb emissions were found in coarse particles (PM>10). • Gas-phase lead constitutes a significant portion of total emissions, indicating the need for careful monitoring. • Advanced technologies could significantly reduce Pb emissions by 24.3 % and 48.6 % from lead and zinc smelters. [ABSTRACT FROM AUTHOR]

Lead (Pb) pollution in sediments remains a major concern for ecosystem quality due to the robust interaction at the sediment/water interface, particularly in shallow lakes. However, understanding the mechanism behind seasonal fluctuations in Pb mobility in these sediments is lacking. Here, the seasonal variability of Pb concentration and isotopic ratio were investigated in the uppermost sediments of a shallow eutrophic drinking lake located in southeast China. Results reveal a sharp increase in labile Pb concentration during autumn-winter period, reaching ∼ 3-fold higher levels than during the spring-summer seasons. Despite these fluctuations, there was a notable overlap in the Pb isotopic signatures within the labile fraction across four seasons, suggesting that anthropogenic sources are not responsible for the elevated labile Pb concentration in autumn-winter seasons. Instead, the abnormally elevated labile Pb concentration during autumn-winter was probably related to reduction dissolution of Fe/Mn oxides, while declined labile Pb concentration during spring-summer may be attributed to adsorption/precipitation of Fe/Mn oxides. These large seasonal changes imply the importance of considering seasonal effects when conducting sediment sampling. We further propose a solution that using Pb isotopic signatures within the labile fraction instead of the bulk sediment can better reflect the information of anthropogenic Pb sources. [Display omitted] • Larger, 3-fold, seasonal fluctuations were observed in the labile Pb concentration. • Pb sources were not responsible for the elevated labile Pb concentration during autumn-winter seasons. • Fe/Mn oxides dominated the seasonal variations of labile Pb concentration. • Algal bloom can increase Pb mobility in sediments. [ABSTRACT FROM AUTHOR]

Dynamic monitoring of environmental Pb2+ is of utmost importance for food safety and personal well-being. Herein, we report a novel, rapid, and practical fluorescence detection platform for Pb2+. The platform comprises two essential components: an e ngineered D NAzyme p robe (EDP) and a r esponsive f unctionalized p robe (RFP). The EDP demonstrates specific recognition of Pb2+ and the subsequent release of free DNA fragments. The released DNA fragments are then captured using the RFP to form DNA complexes, which undergo multiple cascade amplification reactions involving polymerases and nickases, resulting in the generation of a large number of fluorescence signals. These signals can detect Pb2+ at concentrations as low as 0.114 nmol/L, with a dynamic range spanning from 0.1 nmol/L to 50 nmol/L. Moreover, the platform exhibits excellent sensitivity and selectivity for Pb2+ detection. To further validate its effectiveness, we successfully quantitatively detected lead contamination in water from Chaohu Lake, and the results aligned closely with those obtained using inductively coupled plasma-mass spectrometry (ICP-MS). Moreover, this platform is suitable for detecting Pb2+ in seawater, soil, and fish samples. These findings confirm the suitability of the current detection platform for the dynamic assessment of Pb contamination in ecological environments, thereby contributing to environmental and food safety. [Display omitted] • The DNA machines were composed of molecular probes and DNA enzymes. • DNA enzyme -triggered signal amplification enables robust signaling of Pb2+. • The DNA machines showed excellent sensitivity and selectivity for Pb2+ detection. • The DNA machines was suitable for detecting Pb2+ in water, soil and fish. [ABSTRACT FROM AUTHOR]

In this study, based on the assessment of soil heavy metals (HMs) pollution using relevant indices, a comprehensive approach combined network environ analysis (NEA), human health risk assessment (HHRA) method and positive definite matrix factor (PMF) model to quantify the risks among ecological communities in a special environment around mining area in northwest Yunnan, calculated the risk to human health caused by HMs in soil, and analyzed the pollution sources of HMs. The integrated risks for soil microorganisms, vegetations, herbivores, and carnivores were 2.336, 0.876, 0.114, and 0.082, respectively, indicating that soil microorganisms were the largest risk receptors. The total hazard indexes (HI T) for males, females, and children were 0.542, 0.591, and 1.970, respectively, revealing a relatively high and non-negligible non-carcinogenic risks (NCR) for children. The total cancer risks (TCR) for both females and children exceeded 1.00E-04, indicating that soil HMs posed carcinogenic risks (CR) to them. Comparatively, Pb was the high-risk metal, accounting for 53.76%, 57.90%, and 68.09% of HI T in males, females, and children, respectively. PMF analysis yielded five sources of pollution, F1 (industry), F2 (agriculture), F3 (domesticity), F4 (nature), and F5 (traffic). [Display omitted] • A comprehensive assessment of the compound anthropogenic activity area was carried out. • Pb was the most serious contaminated element in the soil for entire study area. • Ecosystem risk assessment of HMs in soil was performed using an integrated approach. • Non-carcinogenic risk was higher in children and carcinogenic risk was higher in women. [ABSTRACT FROM AUTHOR]

Perovskite solar cells represent an emerging and highly promising renewable energy technology. However, the most efficient perovskite solar cells critically depend on the use of lead. This represents a possible environmental concern potentially limiting the technologies' commercialization. Here, we demonstrate a facile recycling process for PbI 2 , the most common lead-based precursor in perovskite absorber material. The process uses only hot water to effectively extract lead from synthetic precursor mixes, plastic- and glass-based perovskites (92.6 – 100% efficiency after two extractions). When the hot extractant is cooled, crystalline PbI 2 in high purity (> 95.9%) precipitated with a high yield: from glass-based perovskites, the first cycle of extraction / precipitation was sufficient to recover 94.4 ± 5.6% of Pb, whereas a second cycle yielded another 10.0 ± 5.2% Pb, making the recovery quantitative. The solid extraction residue remaining is consequently deprived of metals and may thus be disposed as non-hazardous waste. Therefore, exploiting the highly temperature-dependent solubility of PbI 2 in water provides a straightforward, easy to implement way to efficiently extract lead from PSC at the end-of-life and deposit the extraction residues in a cost-effective manner, mitigating the potential risk of lead leaching at the perovskites' end-of-life. [Display omitted] • Water solubility of PbI 2 is highly temperature dependent, which was exploited for Pb recycling from perovskites. • Pb was fully extracted from different perovskites and PbI 2 recovered in pure form was made into a new perovskite layer. • The extracted perovskite residues were sufficiently depleted in metals to not qualify as hazardous materials. [ABSTRACT FROM AUTHOR]

Nanoscale zerovalent iron (nZVI) is efficient for removing Pb 2+ and nitrate from water. However, the influence of nitrate, a common groundwater anion, on Pb 2+ removal by nZVI is not well understood. In this study, we showed that under excess Fe 0 conditions (molar ratio of Fe 0 /nitrate > 4), Pb 2+ ions were immobilized more quickly (<5 min) than in nitrate-free systems (∼15 min) due to increasing pH. With nitrate in excess (molar ratio of Fe 0 /nitrate < 4), nitrate stimulated the formation of crystal Pb x Fe 3− x O 4 (ferrite), which provided additional Pb 2+ removal. However, ∼7% of immobilized Pb 2+ ions were released into aqueous phase within 2 h due to ferrite deformation. Oxidation–reduction potential (ORP) values below −600 mV correlated with excess Fe 0 conditions (complete Pb 2+ immobilization), while ORP values ≥−475 mV characterized excess nitrate conditions (ferrite process and Pb 2+ release occurrence). This study indicates that ORP monitoring is important for proper management of nZVI-based remediation in the subsurface to avoid lead remobilization in the presence of nitrate. [ABSTRACT FROM AUTHOR]

Lead pollution in water and soil often transfers to food, advocating tools for on-site detection of lead pollution to ensure both environmental and food safety. We proposed a label-free, dually amplified and homogeneous DNAzyme assay for sensitive and one-pot detection of lead pollution. Instead of using chemically modified DNA substrate, a structure-response digestion process was introduced to monitor Pb2+ presence-induced cleavage process of unlabeled substrate, further amplifying the response signals and eliminating the use of labeled DNA probes. The DNAzyme assay allowed to detect Pb2+ as low as 0.12 nM and endued a dynamic range from 0.1 nM to 30 nM. In addition, it can specifically identify Pb2+ among other metal ions. We demonstrated that the DNAzyme assay can precisely detect Pb2+ in tap water, milk and fish. Thus, the DNAzyme assay is promising for on-site monitoring lead pollution risk and ensuring environmental and food safety. ga1 • Dually amplification allows to highly sensitive detection of Pb2+. • The DNAzyme assay allows to label-free and one-pot detection of Pb2+. • The DNAzyme assay can strictly discriminate Pb2+ among interfering ions. • Lead pollution in milk and fish was accurately detected. [ABSTRACT FROM AUTHOR]