[Atmospheric concentration of mercury in chlorinated sodium carbonate plants and their vicinity].

The mercury control in the chloroalkali plants is a "routine method". The air is above all sampled in the chloroalkali electrolysis rooms and in the rooms under them. Already in a previous paper we had pointed out a method for the sampling and determination of the metallic mercury in these work rooms. Atmospheric samples are passed through a small glass tube containing fine spongy particles of metallic gold. As far as particle mercury sampling and analysis are concerned, environmental air is filtered by micropore filters placed on the top of the small tube filled with the gold sponge (on the same sampling line). The present work has been made with the purpose of verifying the percentage of metallic and particle mercury of the chloroalkali plants and nearby the industrial perimeter of these plants. The results have been obtained from data of two plants with different capacity, different topographic location and different microclimatic conditions. It has been noticed that the air concentration of mercury in the surrounds of the plants is higher than the basal values in incontaminated areas and the ratio between metallic mercury and particle mercury in the surroundings of chloroalkali plants is casual. The obtained data have been explained at the light of the microclimatic observations and exactly: speed and direction of winds, temperature, humidity and rainy precipitations.