PRESENCE OF TRIAZINE HERBICIDES AND THEIR METABOLITES IN GROUNDWATER OF ITALIAN MAIZE GROWING AREAS Lucio Botteri, Federico Ferrari, Silvia Ghisoni, Gabriele Rocchetti, Luigi Lucini, Marco Trevisan

Lucio Botteri 1 , Federico Ferrari 1 , Silvia Ghisoni 2 , Gabriele Rocchetti 2 , Luigi Lucini 2 , Marco Trevisan 2

1 AEIFORIA srl, Loc. Faggiola 12-16, 29027 Gariga di Podenzano, Italia 2 Dipartimento di Chimica Agraria, Università Cattolica del Sacro Cuore, Piacenza, Italia

The presence of pesticides and their metabolites in groundwater has emerged as an important environmental problem in the last decades. There are several factors that can influence the release of pesticides from fields and their transport into groundwater.

The contamination depends on specific proprieties of chemicals and soil characteristics.

Chemicals which are sufficiently resistant to degradation and are adequately soluble to be transported in water may reach the groundwater in significant amounts.

Furthermore, soil texture and its structure and depth of groundwater play a role for pesticide contamination.

According to National report on pesticides in water 2015 - 2016 (ISPRA), in Italy triazine herbicides and their metabolites are among the substances most frequently detected in groundwater. While terbuthylazine is still used under restriction, atrazine was banned in 1992.

The aim of the research project is to investigate the presence of atrazine, terbuthylazine and their metabolites in groundwater in Italian maize-growing areas to evaluate their behaviour on a multiannual time scale in order to highlight the groundwater contamination due to the widespread use and to the environmental persistence of these substances.

A preliminary analysis conducted on different groundwater samples from Aeiforia wells and piezometers network, lead us to choose five sites where the concentration of these chemicals was significantly high. A three-years sampling campaign was carried out.

The average concentrations measured in the five wells are depicted as follows: atrazine 8.5 –17.2 ng/L, atrazine-desethyl 1.7 –10.7 ng/L, terbuthylazine 5.2 –9.7 ng/L, terbuthylazine-desethyl 6.0 –17.8 ng/L. In each well, the concentration of atrazine is always higher than its metabolite, while the concentration of terbuthylazine-desethyl is higher than its parent compound. Looking at the results, it is interesting to note how the concentrations of metabolites seem to increase during the spring months.

During this period the concentration of atrazine and atrazine-desethyl remain broadly constant, this result can be justified by the fact that the parent compound has been banned since 1992. On the contrary, terbuthylazine and its metabolite show a fluctuant trend throughout the years. This behaviour could depend on weather conditions and field applications.

Despite the concentrations were below the limit established by European Commission, and the use of these molecules is banned or strictly regulated, triazines and their metabolites are still present in groundwater and it determines an important environmental concern.