Mapping and hazard assessment of atmospheric pollution in a medium sized urban area using the Rasch model and geostatistics techniques

Researchers or decision-makers frequently need information about atmospheric pollution patterns in urbanized areas. The preparation of this type of information is a complex task, due to the influence of several individual pollutants, with different units, on the global air pollution (e.g. nitrogen dioxide concentrations, ppm, and noise, dB). In this work, a new methodology based on the formulation of the Rasch model is proposed to obtain a measure of the atmospheric pollution. Two main results were obtained after applying this method: (1) A classification of all locations according to the pollution level, which was the value of the Rasch measure; (2) The influence on the environmental deterioration of each individual pollutant (particularly, in this work, NO2, NO, CO2, CO and noise). Finally, pollution at locations where no measurements were available was estimated with the optimum interpolation technique, kriging. Kriged estimates were subsequently used to map atmospheric pollution. To illustrate the application of this two-step method (Rasch model plus interpolation), which is useful to generate hazard assessment maps based on the spatial distribution of atmospheric pollution, an example is shown.