Dear authors:
Your paper is accepted for publication in ACP subject to technical corrections.

The corrections you should make are:
L37: change “their backward trajectories” to “airmass backward trajectories”.
L58: delete “human”.
L105-107: some details should be given here. You collected weekly TSP samples. How did you avoid the impact of snow/rain on the sampling? Your sampling flowrate was 100L/min at standard condition. Did you use a mass flow controller? Or you just converted the flowrate to the standard condition based on measurements of meteorological parameters?
L137: Do you mean the detection limit for (all cations + all anions)? I think it is better to list the detection limits for all measured ions.
L 226: change “imply” to “implies”.
L357-359: “was observed” or “was not observed”?
Fig. S3: I guess the X-axis of the bottom panels represents latitude and longitude in decrement. If so, make it clear. Some digits in the values at the lower left corner seem to be cut. Please make a correction.

Xiaobin Xu