Metal-Containing Nanoparticles in Low-Rank Coal-Derived Fly Ash from China: Characterization and Implications toward Human Lung Toxicity

Abstract

Characterization of nanoparticles (NPs) in coal fly ashes (CFAs) is critical for better understanding the potential health-related risks resulting from coal combustion. Based on single-particle (SP)-inductively coupled plasma mass spectrometry (ICP-MS) coupled with transmission electron microscopy techniques, this study is the first to determine the concentrations and sizes of metal-containing NPs in low-rank coal-derived fly ashes. Despite only comprising a minor component of the studied CFAs by mass, NPs were the dominant fraction by particle number. Fe- and Ti-containing NPs were identified as the dominant NPs with their particle number concentration ranging from 2.5 × 107 to 2.5 × 108 particles/mg. In addition, the differences of Fe-/Ti-containing NPs in various CFAs were regulated by the coalification degree of feed coals and combustion conditions of all of the low-rank CFAs tested. In the cases where these NPs in CFAs become airborne and are inhaled, they can be taken up in pulmonary interstitial fluids. This study shows that in Gamble’s solution (a lung fluid simulant), 51–87% of Fe and 63–89% of Ti (ratio of the mass of Fe-/Ti-containing NPs to the total mass of Fe/Ti) exist in the NP form and remain suspended in pulmonary fluid simulants. These NPs are bioavailable and may induce lung tissue damage.

Magnetic Fractions of PM2.5, PM2.5–10, and PM10 from Coal Fly Ash as Environmental Pollutants

“…36−38 Unfortunately, little information is still available about the actual phase composition of anthropogenic magnetic particles, although the concentration of Fe in PM is often determined. 36,39 The dependences between the contents of individual components of the narrow fractions of FSs and particle size have been identified. The contents of Fe 2 O 3 and CaO increase as the d av parameter rises from 1 to 7 μm.…”

“…X-ray diffraction (XRD) analysis (Table ) has revealed that narrow fractions of FSs contain crystalline iron-bearing phases, including ferrospinel, α-Fe 2 O 3 and ε-Fe 2 O 3 , mullite and quartz phases, and the amorphous glass phase. Quantifying the contents of iron-rich phases in fine fractions of FSs is an important part in understanding the health risks associated with magnetic pollution from CFAs. − Unfortunately, little information is still available about the actual phase composition of anthropogenic magnetic particles, although the concentration of Fe in PM is often determined. , …”

Importance of Punctual Monitoring to Evaluate the Health Effects of Airborne Particulate Matter

“…However, the presence of small particulate matter, which acts as a carrier for these pollutants, can widen their range, allowing them to reach deep into the respiratory tract, with potentially more serious clinical consequences than those normally induced by these pollutants. The presence of metals (iron, manganese, vanadium, or nickel derived from combustion or platinum, palladium, and rhodium present in catalytic converters in motor vehicles) on the surface of the particles increases tissue irritation and allows their transfer to cells [ 47 ]. In addition, their catalytic effect promotes the formation of tissue-damaging oxidants in situ.…”

Characterization of nano-scale mineral dust aerosols in snow by single particle inductively coupled plasma mass spectrometry

“…In this regard, TiO 2 NPs have been of particular interest due to their release as ENPs from products such as paints and sunscreens, as well as their incidental release to the environment from coal burning. 8,9 Studies have characterized the direct release of TiO 2 NPs from these products and processes, but a reliable method for discrimination between Ti-bearing natural nanoparticles (NNPs) and ENPs in environmental samples has not been fully established. 10,11 MDAs provide a diverse NNP background population, which can be characterized to further refine methods for detection of some ENPs.…”