Heterogeneous (gas-solid) chemistry of atmospheric Cr: A case study of Astana, Kazakhstan.
Environ Pollut
; 344: 123210, 2024 Mar 01.
Article
in En
| MEDLINE
| ID: mdl-38154776
ABSTRACT
Hexavalent chromium (Cr(VI)) is a known carcinogen derived from both anthropogenic and natural sources. This work reports the size-segregated concentrations of total Cr(VI) in particulate matter (PM) in Astana, the capital of Kazakhstan, and provides new insights into the gas-solid reactions of atmospheric Cr. A study of total Cr(VI) in the particulate matter, via a microwave-assisted digestion technique, was conducted using a 5-stage Sioutas Cascade impactor that captures airborne particles in size ranges >2.5 µm, 1.0-2.5 µm, 0.50-1.0 µm, 0.25-0.50 µm, and <0.25 µm. The total Cr(VI) concentration in the size fraction <0.25 µm was the highest with a maximum value of 9.7 ng/m3. This high concentration may pose a greater risk because smaller airborne particles can penetrate deeper into the lower respiratory tract of the lungs. Total suspended particles Cr(VI) exceeded the 8.0 ng/m3 Reference Concentration (RfC) by 22 times. The overall total Cr(VI) concentration in summer was significantly higher than in fall (p < 0.05), which could be due to factors, including higher temperatures, ozone, and NO2 concentrations in summer and a higher VOC concentration in fall. The results indicate that the interaction between Cr(III) and Cr(VI) through gas-solid reaction can control the speciation of atmospheric Cr.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Ozone
/
Chromium
Country/Region as subject:
Asia
/
Europa
Language:
En
Journal:
Environ Pollut
Journal subject:
SAUDE AMBIENTAL
Year:
2024
Document type:
Article
Affiliation country: