A new simple method is proposed for identifying sources of small scale pollution, by determining the tissue
concentrations of pollutants in terrestrial mosses. The method is based on spatial characterization of the processes that
generate accumulation of pollutants in these organisms. The steps involved in implementing and applying the method are:
(i) obtaining data on pollutants in moss samples collected at least at 35 pairs of sampling sites (SS) separated by 1 km
distance; (ii) study of the distribution of the differences in concentration between the pairs of SS, eliminating pairs affected
by foci that generate small scale processes; (iii) characterization of the resulting normal distributions and calculation, for
different levels of significance, of the probability of a value lying within these distributions, and (iv) application of the
calculated quantiles to data corresponding to the differences in concentrations between pairs of SS in the vicinities of foci
of small scale pollution, to determine which elements can be considered as pollutants. Given the small number of data
required once the distribution of the differences has been established, the method is an inexpensive, efficient way of
establishing the probability that a pollutant is being emitted from a particular source. The method is very useful for
verifying the results of pollution inventories, evaluating new technologies and improving the design of regional networks
for biomonitoring of air quality with terrestrial mosses.
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