Atmospheric particulate mercury at the urban and forest sites in central Poland.

Patrycja Siudek,Marcin Frankowski,Jerzy Siepak

doi:10.1007/s11356-015-5476-5

Abstract

Particulate mercury concentrations were investigated during intensive field campaigns at the urban and forest sites in central Poland, between April 2013 and October 2014. For the first time, quantitative determination of total particulate mercury in coarse (PHg2.2) and fine (PHg0.7) aerosol samples was conducted in Poznań and Jeziory. The concentrations in urban fine and coarse aerosol fractions amounted to <MDL ± 77.1 pg m−3 and <MDL ± 604.9 pg m−3, respectively. Aerosol samples collected during the whole study period showed statistically significant differences for particulate mercury concentrations. A strong impact of meteorological conditions (wind velocity, air mass direction, air temperature, and precipitation amount) on particulate mercury concentrations was also observed. In particular, higher variation and concentration range of PHg0.7 and PHg2.2 was reported for wintertime measurements. An increase in atmospheric particulate mercury during the cold season in the study region indicated that coal combustion, i.e., residential and industrial heating, is the main contribution factor for the selected particle size modes. Coarse particulate Hg at the urban site during summer was mainly attributed to anthropogenic sources, with significant contribution from resuspension processes and long-range transport. The highest values of PHg0.7 and PHg2.2 were found during westerly and southerly wind events, reflecting local emission from highly polluted areas. The period from late fall to spring showed that advection from the southern part of Poland was the main factor responsible for elevated Hg concentrations in fine and coarse particles in the investigated region. Moreover, September 2013 could be given as an example of the influence of additional urban activities which occurred approx. 10 m from the sampling site—construction works connected with replacement of the road surface, asphalting, etc. The concentrations of particulate Hg (>600.0 pg m−3) were much higher than during the following months when any similar situation did not occur. Our investigations confirmed that Hg in urban aerosol samples was predominantly related to local industrial and commercial emissions, whereas the main source of Hg in particulate matter collected at the forest site was connected with regional anthropogenic processes. This paper provides the results of the first long-term measurements of size-fractionated particulate mercury conducted in central Poland, which could be an important insight into atmospheric Hg processes within such a scarcely investigated part of Europe.

Highlights

Atmospheric chemistry of mercury is associated with a variety of natural and anthropogenic sources, among which local, regional, and global industrial and urban activities play the most important role (Pacyna et al 2010)
Siudek et al (2011) studied the variability of total particulate mercury (TPM) in Gdynia over the 1-year study period in 2008–2009, using the Principal Component Analysis method, and found large wintertime fluctuations of Hg both in fine and coarse aerosol fractions, with the mean value of 4.1±6.7 pg m−3 and 35.5±28.5 pg m−3, for TPM0.7 and TPM2.2, respectively. These investigations provided a significant insight into pollution sources, atmospheric processes, seasonal patterns, and various factors controlling the concentrations of particulate mercury at urban sites
We present the first long-term measurements of particulate mercury in the urban and forest sites in central Poland

Summary

Introduction

Atmospheric chemistry of mercury is associated with a variety of natural and anthropogenic sources, among which local, regional, and global industrial and urban activities (coal combustion processes) play the most important role (Pacyna et al 2010). Both these forms are less volatile, more water-soluble, and more chemically reactive than GEM and have much shorter atmospheric lifetime (i.e., minutes to weeks) Their vertical distribution in the troposphere is often limited to emission areas due to rapid removal processes via dry and wet deposition (Lindberg et al 2007). Siudek et al (2011) studied the variability of total particulate mercury (TPM) in Gdynia (northern Poland) over the 1-year study period in 2008–2009, using the Principal Component Analysis method, and found large wintertime fluctuations of Hg both in fine and coarse aerosol fractions, with the mean value of 4.1±6.7 pg m−3 and 35.5±28.5 pg m−3, for TPM0.7 and TPM2.2, respectively These investigations provided a significant insight into pollution sources, atmospheric processes, seasonal patterns, and various factors controlling the concentrations of particulate mercury at urban sites. We compared our results with other urban/ industrial and remote/forest areas

Materials and methods

Results and discussion

Summary and conclusions