Pesticide Residues in Surface Water and Groundwater - Pesticides: Evaluation of Environmental Pollution - page 268

be toxic. For instance, 2,6-diethylaniline and 2-ethyl-6-methyaniline are promutagens,
more teratogenic than their parent compounds, metolachlor and alachlor (Kimmel et al.
1986; Osano et al. 2002).
There is considerable information on the occurrence and sources of triazine and chloro-
acetamide TPs in surface water and groundwater. However, information on the occurrence
and faith of other pesticide classes are rather scarce. Degradation of carbamate and OPPs
pesticides was studied in the laboratory conditions, but data on the occurrence of their TPs
in the environment is insufficient. Some of the reasons for avoiding the studying of pesti-
cide TPs in environmental samples are as follows: many of these compounds are still not
well known; they are usually more polar than the parent compounds and their isolation
from the water matrix is more difficult; and the commercial availability of reference stan-
dards is rather limited. Also, if TPs are included in water analysis, the number of potential
analytes to be investigated in water would drastically increase. Another problem could be
the selection of relevant pesticide TPs for monitoring studies. For instance, depending on
the properties of the matrix, the same pesticide can form different TPs. In order to have a
clear picture on water contamination by pesticides, research should include a variety of
TPs and their parent compounds from different pesticide classes.
9.3 Regulatory Issues and Levels of Pesticide Residues
in Surface Water and Groundwater
The wide usage of pesticides in agriculture not only causes contamination of agricultural
crops but also affects the whole environment. Over the last two decades, the extensive con-
tamination of aquatic and soil ecosystems has forced the adoption of restrictive legislative
measures to protect the environment against pollution.
9.3.1 Regulatory Issues Concerning Pesticide Residues
in Surface Water and Groundwater
In the European Union (EU), the presence of pesticides in the aquatic environment is regu-
lated through various directives that set restrictive limits for individual and total pesti-
cides and demand regular monitoring (Council of the European Communities 1975, 1979,
1980; Council of the European Union 1998, 2000, 2001). The first legislation adopted was the
Directive concerning the quality required of surface water intended for the abstraction of
drinking water in the Member States (Council of the European Communities 1975). In 1980,
the first official act regarding the quality of drinking water was accepted, relating to the
quality of water intended for human consumption (Council of the European Communities
1980). The EU adopted the Directive establishing a framework for Community action in
the field of water policy, with the objective to improve, protect, and prevent further dete-
rioration of water quality across Europe (Council of the European Union 2000). Decision
2455/2001/EC (Council of the European Union 2001) has established a list of 33 priority
substances in the field of water protection, the third of which are pesticides. Directive
2008/105/EC (Council of the European Union 2008) set environmental quality standards
(EQS) on the concentration of 41 dangerous chemical substances in surface waters, includ-
ing 33 priority substances and 8 other pollutants that pose a particular risk to animal and
plant life in the aquatic environment and to human health. In that way, EQSs were set for