An experimental reconstruction of the air quality in the Roman vicus Eisenberg

The air quality in ancient Roman cities is still unclear, but historical sources suggest that there was noticeable air pollution, at least in terms of odour. As a pilot study for a smaller settlement, we simulated the combined pollution from heating, cooking and industrial activities. The Roman vicus modelled is located in the modern town of Eisenberg (Pfalz), in the Pfalz region, near Kaiserslautern. Utilising archaeological data on pottery locations and historical buildings, the simulation was conducted to estimate air pollution levels around the vicus.

The simulation utilised the German regulatory pollution dispersion model AUSTAL, driven by weather data from the Copernicus European reanalysis (CERRA) and the SRTM topographic dataset. The Roman vicus consisted of almost twenty buildings, most of which have been archaeologically excavated and are well documented. The vicus is known to have housed potteries, but in most cases the actual use of the excavated houses is unknown. Therefore, we had to assume the location of the pottery workshops in the eastern part. The industrial sources were modelled after measurements taken during experimental pottery production by LEIZA, Mainz, in a reconstructed kiln. The residential sources were modelled after hourly recordings of firewood usage in Nepal, where traditional rural buildings are remarkably similar to those of the Roman period in Central Europe.

The simulation showed clearly the benefits of considering daily cycles rather than averages in the modelling of the air quality. The results obtained demonstrated that, in general, the pollution levels were found to be low when compared to today's limits. However, it turns out that the levels of pollutants are similar to those found in contemporary villages where houses are mainly heated with wood and briquettes.