Organic carbon content in the particulate matter emitted by rural soils.
A laboratory assessment.
Abstract
The aim of this study was to assess the organic carbon (OC) content in
the PM10 emitted by agricultural soils and rural roads under controlled
conditions. Samples were collected from agricultural soils and rural
roads. The PM10 was generated and collected using an electrostatic
precipitator coupled with the Easy Dust Generator (EDG). This procedure
ensures that the PM10 collected come specifically from soil. OC contents
were measured in both the soil and PM10. The enrichment ratio (ER) was
calculated as the ratio between OC content in the PM10 and OC content in
the soil. The results showed that OC content in the PM10 ranged from 2.7
to 3.5 % in agricultural soils and from 1.4 to 2.9 % in rural roads.
These values were comparable to the OC contents observed in fine
particles transported by the wind, but lower than OC contents observed
in PM10 samples collected in rural areas using active samplers and
filters. A quadratic function described the association between OC in
PM10 and OC in the soil. A negative potential function described the
association between ERs and OC in the soil. Both associations suggested
a saturation of OC in PM10 when the OC content in the soil was high.
This information is crucial for a better comprehending of the dust
emission role in the redistribution of OC within terrestrial ecosystems
and to the atmosphere and oceans.