marginally changed since this report was published. According to Jeschke (Jeschke
2018), however, only few enantiomerically pure products are produced on an
industrial scale (>100 t annual production). Since 2007 ca. 43% of the 44 products
launched were chiral and ca. 47% of those were produced in the racemic form.
Nevertheless, this quite overwhelming number of chiral agrochemicals potentially
applied in unknown quantities on agricultural soils today presents the most important environmental platform (in addition to the growing concern on chiral
pharmaceutic residues) for method development and risk assessments in modern
enantiomer-selective environmental chemistry.
Also here, as already demonstrated for other contaminant classes, the classical
single compound approach for environmental assessments is expected to meet its
limits when it comes to comprehensive environmental risk and exposure assessments (Meyer 2003; Albuquerque et al. 2016; Kim Tiam et al. 2016; Aamir et al.
2017; Panizzi et al. 2017; de Albuquerque et al. 2018). Toxicological aspects and
exposure as well as the role of enantiomer-selective analysis associated with new
evaluation approaches will be discussed in detail in Chap. 10. However, the importance of chirality and enantiomer-selective analytical methods for the determination
of enantiomeric profiles is stressed as an essential feature for the assessment of
bioavailability and transformation pathways in target suspect and even-non-target
strategies today (Meng et al. 2009; Ye et al. 2010; Zhou et al. 2014a, b). Based upon
similar considerations, Garrison (2006) argued that the sole application of enantiomeric pure pesticides products would consequently lead to more effective targetfocussed strategies in the fight against pests in modern agriculture.
Nevertheless, taking into account the above reported overwhelming number of
chiral modern pesticides released into the environment via agricultural applications,
it is not possible to give a comprehensive report and appreciation within the limits of
this book. For details on the product characterisation and potential environmental
toxicological consequences, we wish to direct the interested reader to already
available scientific literature on this topic (Nillos et al. 2010; Garrison et al.
2011a, b; Ulrich et al. 2012; Ye et al. 2015; de Albuquerque et al. 2018; Jeschke
2018; Zhao et al. 2018a, b, c).
Here, however, we will present selected relevant examples from the current
literature in order to demonstrate the levels and consequences of unintended pesticide release into the aqueous environment. Already in 2006, Wong reported on the
presence of several contaminants of emerging concern in a general review (Wong
2006). Beside the classical chlorinated substances, the emphasis was placed on
modern pesticides including pyrethroid- and phosphorus-containing pesticides. A
list of 20 modern pesticides was presented for which the enantiomeric profile was
determined mainly in soil and aquatic samples. The already earlier discussed
phenoxyalkanoic acids (e.g. dichlorprop and mecoprop) were identified as the
most prevailing current used pesticides in this survey. Other groups like acetamides,
organophosphorus pesticides and pyrethroids were also found to be relevant environmental pollutants.
A new multi-compound method for the enantiomer-selective determination of
modern pesticides was developed by Ye et al. (2009). This research group developed
an optimised method for the enantiomer separation of synthetic pyrethroids,
8.2 Transformation/Accumulation of Chiral Xenobiotics in Higher Organisms
165
2018), however, only few enantiomerically pure products are produced on an
industrial scale (>100 t annual production). Since 2007 ca. 43% of the 44 products
launched were chiral and ca. 47% of those were produced in the racemic form.
Nevertheless, this quite overwhelming number of chiral agrochemicals potentially
applied in unknown quantities on agricultural soils today presents the most important environmental platform (in addition to the growing concern on chiral
pharmaceutic residues) for method development and risk assessments in modern
enantiomer-selective environmental chemistry.
Also here, as already demonstrated for other contaminant classes, the classical
single compound approach for environmental assessments is expected to meet its
limits when it comes to comprehensive environmental risk and exposure assessments (Meyer 2003; Albuquerque et al. 2016; Kim Tiam et al. 2016; Aamir et al.
2017; Panizzi et al. 2017; de Albuquerque et al. 2018). Toxicological aspects and
exposure as well as the role of enantiomer-selective analysis associated with new
evaluation approaches will be discussed in detail in Chap. 10. However, the importance of chirality and enantiomer-selective analytical methods for the determination
of enantiomeric profiles is stressed as an essential feature for the assessment of
bioavailability and transformation pathways in target suspect and even-non-target
strategies today (Meng et al. 2009; Ye et al. 2010; Zhou et al. 2014a, b). Based upon
similar considerations, Garrison (2006) argued that the sole application of enantiomeric pure pesticides products would consequently lead to more effective targetfocussed strategies in the fight against pests in modern agriculture.
Nevertheless, taking into account the above reported overwhelming number of
chiral modern pesticides released into the environment via agricultural applications,
it is not possible to give a comprehensive report and appreciation within the limits of
this book. For details on the product characterisation and potential environmental
toxicological consequences, we wish to direct the interested reader to already
available scientific literature on this topic (Nillos et al. 2010; Garrison et al.
2011a, b; Ulrich et al. 2012; Ye et al. 2015; de Albuquerque et al. 2018; Jeschke
2018; Zhao et al. 2018a, b, c).
Here, however, we will present selected relevant examples from the current
literature in order to demonstrate the levels and consequences of unintended pesticide release into the aqueous environment. Already in 2006, Wong reported on the
presence of several contaminants of emerging concern in a general review (Wong
2006). Beside the classical chlorinated substances, the emphasis was placed on
modern pesticides including pyrethroid- and phosphorus-containing pesticides. A
list of 20 modern pesticides was presented for which the enantiomeric profile was
determined mainly in soil and aquatic samples. The already earlier discussed
phenoxyalkanoic acids (e.g. dichlorprop and mecoprop) were identified as the
most prevailing current used pesticides in this survey. Other groups like acetamides,
organophosphorus pesticides and pyrethroids were also found to be relevant environmental pollutants.
A new multi-compound method for the enantiomer-selective determination of
modern pesticides was developed by Ye et al. (2009). This research group developed
an optimised method for the enantiomer separation of synthetic pyrethroids,
8.2 Transformation/Accumulation of Chiral Xenobiotics in Higher Organisms
165