Biomonitoring passive sampling

Both passive sampling and biomonitoring have strengths and weaknesses. Their main advantages are that they can provide information on average concentrations of pollutants over periods of time from weeks to months, and because tiiey accumulate analytes over a period of time, they accumulate larger amounts than would be present... 

Two procedures of biomonitoring are available to estimate the pollution of aquatic locations passive biomonitoring by sampling plant material from natural sites and active biomonitoring using plant material exposed to the sites. 

Passive biomonitoring was applied to estimate the air quality in the La Spezia district, Italy, with regard to a coal-fired power plant and other industrial activities (Nimis et al., 1990). The lichen Parmelia caperata collected from Olea sativa trees was meant to biomonitor the SO2 pollution in the study area. The method, adopted by Nimis et al., was designed to avoid subjectivity, to begin with the strategy of sampling and end with the analysis of data. The applied index, based on frequency of species... 

Bargagli et al. (1997) performed a study which applied a method of passive biomonitoring of trace element deposition in urban, industrial and reference areas in Italy, especially in Tuscany, Veneto and Friuli, by means of epiphytic lichens, mainly P. caperata, P. sulcata and X. parietina. Despite the fact that the Pb content of gasoline in Italy was lowered from 0.4 to 0.15 g in 1991, samples of P. caperata collected in the urban environment of Siena still contained considerable amounts of Pb. The data presented in this study included average amounts of Al, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb and Zn in lichens from five urban areas in northern and central Italy, from the entire region of Veneto, Tuscany and from remote areas in Calabria. It was shown that the pattern of urban pollution was characterized to a great extent by high values of Al, Cd, Cu, Ni and Pb. Traffic appeared to play a prominent role as these metals are known to be released by vehicular activity. 

Thus, the distinct metal contents are at least partly caused by the different ages and phenotypes. Varying metal concentrations of the plant material are not only a result of differences in water pollution. Using F. antipyretica for passive biomonitoring, the variation of age and phenotype has to be considered. Repeated measurements throughout the seasons can confirm the results and give an impression of the metal pollution of the sampling sites. 

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