I. Mirgain et al., ATRAZINE CONTAMINATION OF GROUNDWATERS IN EASTERN FRANCE IN RELATION TO THE HYDROGEOLOGICAL PROPERTIES OF THE AGRICULTURAL LAND, Environmental technology, 14(8), 1993, pp. 741-750
In Alsace, groundwater contamination by atrazine has been studied on a
seasonal basis at 6 sampling sites (5 groundwater wells and a river)
covering an agricultural area of approximately 32 km2 where corn has b
een cultivated intensively for the previous 10 years. Three atrazine -
treated fields have also been analysed in order to follow the seasona
l variations of the pesticide concentration in the soil following the
annual treatment. During the three years of this study (May 1990 to Au
gust 1992), high atrazine concentrations (exceeding 0.2 mug l-1) were
detected at all sites studied with higher concentrations present at th
e beginning of summer. Some of the sites were contaminated with atrazi
ne at concentrations ranging from 250 mug l-1 to 1500 mug l-1. The con
tamination of a river, for which the main sources are groundwater and
drainage water, by this herbicide reflects the events occurring in sub
-surface water. Atrazine concentrations reached 0.6 to 2.0 mug l-1 dur
ing the critical months (May to June) indicating that a river crossing
an agricultural area has the capacity to transport large quantities o
f polluting atrazine which may consequently lead to the contamination
of neighbouring lands. This 3 year study provides useful information c
oncerning the persistence of atrazine in soil as well as studying the
rate of groundwater contamination. The results demonstrate that a larg
e amount of atrazine reaches groundwater a few days after spraying. Me
teorological conditions, permeability of the treated soils and agricul
tural practices are the three major parameters which enhance water pol
lution by pesticides and prompt questions as to the danger of certain
pesticides on vulnerable ecosystems.