Subcellular metal distribution assessments are the most adequate biomonitoring approach to evaluate metal toxicity, instead of total metal assessments This study aimed to assess subcellular metal distributions and associations to the main metal exposure biomarker, metallothionein (MT), in two bromeliad species ( and ) exposed established in industrial, urban, and port areas in the metropolitan region of Rio de Janeiro, southeastern Brazil, through an active biomonitoring approach conducted one year. Metals and metalloids in three subcellular fractions (insoluble, thermolabile and thermostable) obtained from the MT purification process were determined by inductively coupled plasma mass spectrometry (ICP-MS). Lower MT concentrations were observed both during the dry sampling periods, associated to the crassulacean acid metabolism (CAM) and during the COVID-19 pandemic, due to reduced urban mobility, decreasing pollutant emissions. The percentage of non-bioavailable metals detected in the insoluble fraction increased throughout the sampling period for both species. Several metals (Cr, Co, Cu, Cd, Mn, Ni, Se, and Zn), most associated with vehicle emissions, the main pollutant source in urban centers, were detected in the thermostable fraction and are, thus, associated with MT through the MT-metal detoxification route. Insoluble metal concentrations were higher in , indicating that this species seems less susceptible to cellular metal exposure damage. A potential protective effect of Se and Fe was detected against Pb, suggested by a strong negative correlation, which may be attributed to antioxidant roles and similar uptake routes, respectively.

中文翻译：

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对巴西大都市暴露于城市污染的大气生物监测器进行生态毒理学评估

亚细胞金属分布评估是评估金属毒性最合适的生物监测方法，而不是总金属评估。本研究旨在评估两种暴露的凤梨科植物物种 ( 和 ) 的亚细胞金属分布以及与主要金属暴露生物标志物金属硫蛋白 (MT) 的关联通过为期一年的积极生物监测方法，在巴西东南部里约热内卢大都市区的工业、城市和港口地区建立了该项目。通过电感耦合等离子体质谱 (ICP-MS) 测定从 MT 纯化过程中获得的三种亚细胞组分（不溶性、不耐热和耐热）中的金属和类金属。在与景天酸代谢 (CAM) 相关的干燥采样期间和在 COVID-19 大流行期间，由于城市流动性减少、污染物排放减少，都观察到了较低的 MT 浓度。在两个物种的整个采样期间，在不溶性部分中检测到的非生物可利用金属的百分比都增加了。在热稳定部分中检测到了几种金属（Cr、Co、Cu、Cd、Mn、Ni、Se 和 Zn），这些金属与车辆排放（城市中心的主要污染物源）最相关，因此通过以下方式与 MT 相关： MT-金属解毒途径。不溶性金属浓度较高，表明该物种似乎不太容易受到细胞金属暴露损伤的影响。检测到 Se 和 Fe 对 Pb 具有潜在的保护作用，强烈的负相关表明这可能分别归因于抗氧化作用和相似的吸收途径。