scholarly journals Exposure assessment of elemental carbon, polycyclic aromatic hydrocarbons and crystalline silica at the underground excavation sites for top-down construction buildings

PLoS ONE ◽  
2020 ◽  
Vol 15 (9) ◽  
pp. e0239010
Author(s):  
Hyunhee Park ◽  
Eunsong Hwang ◽  
Miyeon Jang ◽  
Chungsik Yoon
2012 ◽  
Vol 9 (12) ◽  
pp. 19165-19197 ◽  
Author(s):  
C. Theodosi ◽  
C. Parinos ◽  
A. Gogou ◽  
A. Kokotos ◽  
S. Stavrakakis ◽  
...  

Abstract. To assess sources and major processes controlling vertical transport of both anthropogenic and natural chemical species in deep basins of the Eastern Mediterranean Sea (SE Ionian Sea, Nestor site), we performed chemical characterization (elemental carbon, major and trace metals and polycyclic aromatic hydrocarbons) of marine sinking particles. Sediment traps were deployed at five successive depths, 700 m, 1200 m, 2000 m, 3200 m and 4300 m from the sea surface, during the period of May 2007 to October 2008. Fluxes of all measured species exhibited minimum values from January to March 2008 and maximum from April to September 2008, with an evident covariance revealing a common and rapid vertical transport mechanism from 700 m down to 4300 m depth. Crustal matter flux from atmospheric deposition plays an important role in the temporal variability of particulate matter with significant contribution from biogenic constituents namely the seasonal succession in the export of planktonic biomass, expressed by particulate organic carbon (POC), carbonates and biogenic Si fluxes (Stavrakakis et al., 2012). Tracers (elemental carbon, retene) of the devastating forest fires occurred in August 2007 in southern Greece, were detected at sediment trap material in all depths with a delay of 15 days at 4300 m, indicating a rapid and well-coupled transport of sinking particulate material between the sea-surface and deep layers of the Eastern Mediterranean Sea. Lateral inputs of pollutants at the deepest trap (4300 m) are probably of importance, due to the influence of deep Adriatic water at the study site.


2019 ◽  
Vol 623 ◽  
pp. A134 ◽  
Author(s):  
T. Pino ◽  
M. Chabot ◽  
K. Béroff ◽  
M. Godard ◽  
F. Fernandez-Villoria ◽  
...  

Context. Top-down chemistry is believed to be responsible for the formation of the large molecular compounds such as the polycyclic aromatic hydrocarbon-like molecules and the fullerenes observed in the interstellar medium. The release of these large molecules from the parent grains remains an important issue to be investigated. Aims. Cosmic rays irradiate the dust grains during their journey in the interstellar medium. In this study we probe to what extent electronic sputtering and/or desorption processes induced by high-energy ion projectiles contribute to the creation of the large molecular component in space. Methods. Carbonaceous dust analogues were produced in an ethylene flame. The resulting soot nanoparticles generated under well-defined conditions were irradiated by swift heavy ions, and mass spectra of the ionic and neutral molecular fragments emitted shortly after the impact were monitored. Results. Large molecular fragments were detected, including neutral and ionic polycyclic aromatic hydrocarbons containing up to several tens of carbon atoms, as well as ionic fullerenes. Although the absolute efficiencies were not obtained, these experiments provide a proof of principle of a top-down scenario involving interaction processes of interstellar dust with high-energy projectiles yielding large molecular compounds observed in space.


2013 ◽  
Vol 21 (23) ◽  
pp. 13152-13159 ◽  
Author(s):  
Maria Pia Gatto ◽  
Claudio Gariazzo ◽  
Andrea Gordiani ◽  
Nunziata L’Episcopo ◽  
Monica Gherardi

Sign in / Sign up

Export Citation Format

Share Document