Seasonal mercury concentrations measured in rural air in Southern Poland: Contribution from local and regional coal combustion

The concentration of total atmospheric gaseous mercury (TGM) and total particulate mercury (TPM) have been measured during one summer campaign (19–29 August 2003) and one winter campaign (26 January–3 February 2004) at a rural site in Poland. Mercury deposition was also measured using bulk samplers. The measurement campaigns were performed in a typical agricultural area of Southern Poland where 85% of the houses use low capacity domestic heating units (DHUs) fuelled with hard coal during the cold season. An average TGM value of 1.63±0.35ngm-3 was obtained in the summer campaign, whereas a 2.5 times higher TGM concentration was found during winter. The mean TPM concentration during summer was 0.11±0.05ngm-3 while 10 times higher values were obtained during the winter campaign. The mercury deposition was also found to be much higher during winter in comparison to summer. The summer TGM values are at the same level as the annual average TGM at background locations in most West European countries including Scandinavia. The higher TGM values in winter are most likely due to the use of DHUs in the local area. However, both summer and winter TPM concentrations and mercury deposition fluxes are much higher than in most neighbouring West European countries. This probably reflects the regional use of coal combustion for electric energy production and in low-capacity DHUs.