Date Published: February 23, 2018
Publisher: Public Library of Science
Author(s): Wojciech Dmuchowski, Dariusz Gozdowski, Aneta H. Baczewska-Dąbrowska, Piotr Dąbrowski, Barbara Gworek, Irena Suwara, Andrew C. Singer.
Changes in environmental pollution by S, Cd, Cu, Pb and Zn in 2006–2014 were evaluated using a bioindication method. This method was based on measurements of pollutants in Scots pine (Pinus sylvestris L.) needles. The measurements were performed in the Chojnowskie Forests, a region recognized as a background area for central Poland. The changes in the contents of sulfur (S) and metals in needles were not comparable with the changes in the global emissions of the pollutants in Poland. On average, the pollution level in the study area decreased by 9.9% for S, 61.4% for Pb, 22.5% for Cd, 11.7% for Zn and 10.4% for Cu. During the same period, global emissions in Poland decreased by 38.1% for S, 8.0% for Pb, 63.2% for Cd, 11.7% for Zn and 14.0% for Cu. Therefore, the differences in the changes in emissions and the needle contents of each element should be examined separately which was not a goal of this study. However, the discrepancy between these results did not prevent the use of bioindication methods. Evaluation of pollutant contents in plants reflected their incorporation in biological processes rather than air or soil pollution levels.
Bioindication methods offer an opportunity for significant intensification of studies on air pollution, especially on the content of trace elements. Biomonitoring in a general sense can be defined as the use of plants and animals with the objective of gaining quantitative and qualitative information on certain characteristics of the biosphere [1–4].
The Chojnowskie Forests have an area of 10 200 ha and are characterized by a rather high forest density. Mixed fresh coniferous forest with a predominance of pine constitutes the majority of the habitat at 74.1%, with 9.1% oak and 8.6% birch . The forests are located in central Poland beyond the direct impact of large stationary pollution emitters. The air quality of the Chojnowskie Forests is influenced by the city (Warsaw). However, there are no large industrial emitters in the city. The sources of air pollution in the Chojnowskie Forests are large hard coal-fired power stations: 3 combined heat and power stations in Warsaw (total 4266 MW, located approximately 30 km northeast of the Chojnowskie Forests), Kozienice Power Station (2905 MW) 48 km southeast, and the lignite-fired Bełchatów Power Station (5420 MW) situated approximately 148 km southwest of the Chojnowskie Forests. The flue gases of these plants are emitted into the atmosphere through stacks whose heights are 200–300 m. The air pollution levels of the Chojnowskie Forests can be regarded as background air pollution for central Poland . The locations of the study area and sampling points are presented in Fig 1.
Environmental pollution by sulfur and metals in the Chojnowskie Forests, except for the northern part, mean that it can be recognized as a background area for central Poland. In the northern part, there has been a noticeable influence of pollution from the Warsaw area.