Plants as Monitors of Lead Air Pollution

Abstract

The most important environmental problems are caused by intensive industrial activities, urbanization and population growth. The increase in air pollution resulting from the expanding use of fossil energy sources and the growth in the manufacture and use of chemicals has been accompanied by mounting public awareness of and concern about detrimental effects on health and the environment. Anthropogenic activities have greatly changed pollutant atmospheric concentrations and consequently, their availability and cycling. Airborne lead (Pb) is a constituent of atmospheric particulate matter (PM), and as such it may be transported to great distances before being removed in deposition processes. Here we review the application of plants in (i) trace elements monitoring, (ii) biomonitoring of lead air pollution and (iii) identifying lead sources in the environment. The instrumental monitoring techniques lack information on impact of atmospheric pollutants on the living systems and hence, there has been an increasing interest in using indirect monitoring methods based on a response of living organisms that may act as trace element bioaccumulators. Since plants accumulate lead, as well as other trace elements, from the atmosphere, the indirect air pollution monitoring, using plants has gained importance in the last decades. Mosses, lichens, but also higher plants have been used for biomonitoring of various pollutants, including lead. Lead isotopic studies may provide a convenient approach for studying and tracing the sources of Pb pollution in different environmental compartments. The lead isotope approach for plant biomonitoring in source identification and biomonitoring species validity assessment has been discussed. It has been shown that airborne Pb is the most important source of accumulated Pb in plants. The overview of advantages using plants for lead air pollution monitoring is presented in this paper, as well as the determination of lead sources in the environment.