Assessment of the oxidative potential of fine particles PM2.5 according to their emission sources
Résumé
Fine particulate matter (PM2.5) present in the atmosphere are the subject of
considerable attention from the scientific community and public authorities because of
their proven impacts on climate and health. PM2.5 form a complex mixture of chemical
compounds that can differ according to emission sources. In order to implement
effective air quality management policies, a better knowledge of the sources that
contribute to the concentration of air pollutants as well as the assessment of their
respective effects on health is necessary.
The objective of this study is to estimate the oxidative potential associated with the
sources of fine particles that contribute to the ambient concentrations of PM2.5 in the
Dunkirk area, located in the North of France.
PM2.5 were collected on four sites influenced by urban, road traffic, industrial and rural
emissions. PM2.5 from all four sites were chemically characterized, notably for the
quantification of metal(oid)s, water-soluble ions, total carbon, and water-soluble
organic compounds (Water-Soluble Organic Carbon (WSOC), Humic-Like Substances
(HULIS), carboxylic acid, sugars, quinones as well as Polycyclic Aromatic
Hydrocarbons (PAHs)
Oxidative potential has been evaluated by acellular tests, namely the ascorbic acid
assay (OP-AA) and the dithiothretol assay (OP-DTT). These methods were chosen
because they are easy to use, inexpensive, have high repeatability and are
complementary because they are not sensitive to the same chemical species and
particle sources.