Influence of different levels of traffic pollution on haemoglobin content in the earthworm Lumbricus terrestris

Our aim was to determine haemoglobin content in earthworm populations from sites with different amounts of soil pollution. The study was done on Lumbricus terrestris specimens from four sites: the median strip of a busy street in Cracow; a city park; forest about 30 km from Cracow (100 m from a low-traffic local road); and a forest on calcareous soil about 30 km from Cracow (distant from traffic). There were statistically significant differences in haemoglobin content between study sites. The lowest amount of haemoglobin was found in earthworms from the median strip (2.19 g 100 ml−1), the highest in those from the ‘cleanest’ forest on calcareous soil (3.18 g 100 ml−1). The highest lead concentration was found in specimens from the median strip (12.3 μg g−1) and only trace amounts were found in those from the forest on calcareous soil. There was a negative correlation between haemoglobin and lead concentrations in earthworms. Species composition, density and biomass of earthworm populations at the four sampling sites as well as the body mass of adult individuals of L. terrestris were estimated. No correlation was found between any of these variables and the extent of exposure to traffic pollution.