[Analysis of the detection of metals and metalloids in the bronchoalveolar lavage fluid for the etiological diagnosis value of pneumoconiosis]

Objective: To analyze the differences of the concentrations of metals and metalloids in bronchoalveolar lavage fluid (BALF) of patients with pneumoconiosis, so as to provide reference for the etiological diagnosis of pneumoconiosis. Methods: From September 2019 to August 2020, 47 pneumoconiosis patients hospitalized in Chongqing Prevention and Treatment Center for Occupational Diseases and undergoing bronchoalveolar lavage were selected as the research objects using cluster sampling method. The general situation and occupational history of patients were investigated by questionnaire, The BALF of 47 pneumoconiosis patients was collected, and the concentrations of metals and metalloids in BALF were detected by inductively coupled plasma mass spectrometry (ICP-MS) , the differences among patients with different types of pneumoconiosis, different stages of silicosis and different occupational history were analyzed by one-way ANOVA. Results: The concentrations of 50 metals and metalloids in BALF were detected, and 21 of them were analyzed. Compared with different types of pneumoconiosis, the concentrations of Zn, Mn and Sn in BALF were statistically significant (F=9.959, 3.635, 9.488, P<0.05) . The concentrations of K, Mg, Fe, Zn, Cu and Ni in BALF were significantly different in different stages of silicosis (F=4.271, 4.334, 3.588, 5.120, 7.340, 3.905, P<0.05) . The concentrations of Zn and Sn in pneumoconiosis patients with different types of work and types of exposed dust were significantly different (P<0.05) . Conclusion: The detection of Zn, Mn, Sn, and other metals in BALF can provide reference basis for the etiological diagnosis of pneumoconiosis and provide a new idea for the diagnostic method of pneumoconiosis.

Predicting trace metal solubility and fractionation in Urban soils from isotopic exchangeability

Metal-salt amended soils (MA, n = 23), and historically-contaminated urban soils from two English cities (Urban, n = 50), were investigated to assess the effects of soil properties and contaminant source on metal lability and solubility. A stable isotope dilution method, with and without a resin purification step, was used to measure the lability of Cd, Cu, Ni, Pb and Zn. For all five metals in MA soils, lability (%E-values) could be reasonably well predicted from soil pH value with a simple logistic equation. However, there was evidence of continuing time-dependent fixation of Cd and Zn in the MA soils, following more than a decade of storage under air-dried conditions, mainly in high pH soils. All five metals in MA soils remained much more labile than in Urban soils, strongly indicating an effect of contaminant source on metal lability in the latter. Metal solubility was predicted for both sets of soil by the geochemical speciation model WHAM-VII, using E-value as an input variable. For soils with low metal solution concentrations, over-estimation of Cd, Ni and Zn solubility was associated with binding to the Fe oxide fraction while accurate prediction of Cu solubility was dependent on humic acid content. Lead solubility was most poorly described, especially in the Urban soils. Generally, slightly poorer estimation of metal solubility was observed in Urban soils, possibly due to a greater incidence of high pH values. The use of isotopically exchangeable metal to predict solubility is appropriate both for historically contaminated soils and where amendment with soluble forms of metal is used, as in toxicological trials. However, the major limitation to predicting solubility may lie with the accuracy of model input variables such as humic acid and Fe oxide contents where there is often a reliance on relatively crude analytical estimations of these variables. Trace metal reactivity in urban soils depends on both soil properties and the original source material; the WHAM geochemical model predicts solubility using isotopically exchangeable metal as an input.