Accumulation of heavy metals in gametophytes of the epilithic mosses

Abstract

Heavy metals are hazardous pollutants in urban atmosphere that are released into the environment mainly as a result of industrial activity and high traffic loads. These substances pose a substantial risk to human health and biota in urban ecosystems. Therefore, environmental monitoring of air pollution with metals by using bioindicator species is of great importance. Bryophytes capable of accumulating heavy metals are widely used as bioindicators of environmental pollution for biomonitoring atmospheric metal deposition. The ability of urban epilithic mosses to accumulate heavy metals has not been studied sufficiently. This invistigation was aimed at studying metal-accumula­ting ability of Rhynchostegium murale and Schistidium apocarpum mosses collected within the city of Lviv (Western Ukraine), as well as exploring the relationship between the level of anthropogenic load and the accumulation of heavy metals in moss gametophytes. Two polluted sites in the southern part of the city and one control site in the territory of Stryisky Park were analyzed. The content of heavy metals, namely Cr, Mn, Ni, Pb, and Zn, in moss samples was determined by the atomic absorption spectrophotometry using an atomic absorption spectrometer C-115PK Selmi. The results were processed using statistical methods. It was demonstrated that different levels of metal accumulate in Rhynchostegium murale and Schistidium apocarpum mosses. Depen­ding on the concentration in moss gametophytes sampled in the city of Lviv, the studied metals can be arranged in the following order: Mn> Zn> Cr> Ni> Pb. However, the content of Mn and Zn in the S. apocarpum moss was found to be considerably higher than in R. murale. The gametophytes of both mosses collected in areas subjected to industrial and transport loads in the southern regions of Lviv city had significantly higher concentration of Pb, and R. murale also had an elevated Mn content compared to moss samples collected in green park area. The results of our study suggest that the rate of accumulation of heavy metals in gametophytes of epilithic mosses reflect the level of atmospheric metal deposition in urban areas exposed to the anthropogenic pressures on the environment.

Keywords

• heavy metals
• bryophytes
• urban ecosystems
• environmental monito­ring
• bioindication