Speciation and bioaccessibility of heavy metals in PM2.5 in Baoding city, China. (September 2019)

• Record Type: Journal Article
• Authors: Xie, Jiao-Jiao; Yuan, Chun-Gang; Xie, Jin; Shen, Yi-Wen; He, Kai-Qiang; Zhang, Ke-Gang
• Is Part Of: Environmental pollution. Volume 252(2019):Part A
• Page Start: 336
• Page End: 343
• Publication Date: 2019-09
• Subjects: Particulate matter -- Heavy metals -- Sequential extraction -- In vitro test -- Correlation; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2019.04.106
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: The health risks and toxicity of heavy metals (HMs) in PM2.5 are not only associated with their total amounts, but also with their species and bioaccessibility. In this study, the speciation (fractions) and bioaccessibility of HMs (Pb, Cd, Cr, Cu and Zn) as well as their correlations in fine particulate matter (PM2.5 ) samples from four seasons were studied. A sequential extraction procedure was applied to divide the studied HMs into four fractions: acid-soluble fraction (F1), reducible fraction (F2), oxidative fraction (F3) and residual fraction (F4). The simulated body fluids (gastrointestinal and lung phases) were used for in vitro tests in order to evaluate the bioaccessibility of HMs. The distribution of HMs in PM2.5 was season and element dependent. It was found that Zn was the most abundant element among the five measured metals and followed by Pb, Cu, Cr and Cd. The total contents of each HM in different seasons were in the following order: winter > autumn > spring > summer. The studied HMs were mainly concentrated in acid-soluble fraction (F1) with high bioaccessibility (p < 0.05) except for Cr. Zn, Pb and Cu possessed the highest bioaccessibility in summer while Cd and Cr were the highest in winter. In vitro tests indicated that HMs in PM2.5 were much more accessible to gastrointestinal fluids rather than lung phase (Gamble's solution). A significant correlation was found between the results from the optimized BCR sequential extraction and solubility bioaccessibility research consortium (SBRC). The fractions extracted by SBRC were consistent with the first two fractions extracted by the sequential extraction method. Graphical abstract: Image 1 Highlights: BCR sequential extraction and in vitro test were used to study HMs in PM2.5 . Pb, Cd, Cu and Zn in PM2.5 were mainly existed in F1 with high bioaccessibility. Bioaccessibility and speciation of HMs in PM2.5 varied with different seasons. Correlation was found between BCR sequential extraction and SBRC method. Abstract : High bioaccessibility of HMs in PM2.5 and the significant correlation of SBRC/BCR sequential extraction were discovered.