Autor: |
Baergen AM; Department of Chemistry , University of Toronto , Toronto , Ontario M5S 3H6 , Canada., Donaldson DJ; Department of Chemistry , University of Toronto , Toronto , Ontario M5S 3H6 , Canada.; Department of Physical and Environmental Sciences , University of Toronto at Scarborough , Toronto , Ontario M1C 1A4 , Canada. |
Jazyk: |
angličtina |
Zdroj: |
Environmental science & technology [Environ Sci Technol] 2019 May 21; Vol. 53 (10), pp. 5671-5677. Date of Electronic Publication: 2019 May 02. |
DOI: |
10.1021/acs.est.9b00532 |
Abstrakt: |
Impervious surfaces, especially in urban environments, are coated with a film composed of a complex mixture of substances, referred to as urban grime. Despite its ubiquity, the factors that dictate urban grime composition are still not well understood. Here, we present the first study of the seasonal variation in composition of water-soluble inorganic ions present in urban grime, performed by analyzing samples collected in Toronto for 4-week intervals over the course of a year. A clear seasonality in the composition is evident, with NaCl dominating in the winter months and Ca 2+ and NO 3 - dominant in the summer. We compare the grime composition to the water-soluble ion composition of PM 2.5 and PM 10 in order to infer chemistry occurring within the grime and find evidence that chemistry occurring within the urban grime matrix could provide a source of ClNO 2 and NH 3 to the urban atmosphere. The uptake of water by urban grime also shows a clear seasonality, which may be driven by the changing proportions of nitrate salts and/or oxidized organic compounds over the year. |
Databáze: |
MEDLINE |
Externí odkaz: |
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