As mentioned, pharmaceuticals and personal care products (PPCPs) have been
detected in many environmental samples taken in highly industrialised countries in
wastewater and surface waters, and they are thus classified as emerging pollutants.
However, it was generally assumed that in developing countries the “classical”
pesticides of the first and second generation are prevailing in all environmental
compartments. But meanwhile, the working group of Hühnerfuss presented evidence that this assumption has to be modified considerably (Scheurell et al. 2013,
2014). In Karachi, Pakistan, surface water samples were collected during two
campaigns in December 2006 and April 2007 from the Malir River, the Lyari
River (the two major rivers flowing through Karachi), in the mangrove lagoon,
which is part of Karachi harbour receiving effluents from the central parts of the
city. Additional samples were taken from an open drainage canal system (Korangi
drain) receiving untreated residential and industrial effluents as well as wash-off and
rainwater from the Landhi residential district and from the end of a pipe eluting
waste waters from the district of Clifton across the beach into the Arabian Sea. A
total of 768 fractions from 32 samples were screened for their ecotoxicological
relevance by the luminescent bacteria test. The samples originate from all parts of
the drinking water circuit, including the sources (ground water and surface water),
distribution, processing and tapping points as well as wastewater. The determined
pollution status indicates the alarming condition of the drinking water circuit.
However, contrary to our expectation, no “classical” pesticides of the first and
second generations were prevailing. The waste and surface waters of the city area
of Karachi were severely contaminated with pharmaceuticals and industrial
chemicals (Scheurell et al. 2013, 2014). It is interesting to note that the high
concentrations of the parent compounds and their transformation products allowed
the determination of the molecular structure of several “new” environmental metabolites (Scheurell et al. 2013, 2014). For example, as mefenaminic acid was found in
all environmental water samples in Karachi, the respective transformation product
3-hydroxy-mefenaminic acid was ubiquitously identified and verified by
GC/MS. Further examples of thus far unknown chiral transformation products of
pharmaceuticals are given in related reports (Hühnerfuss 2000; Selke et al. 2010;
Scheurell et al. 2014; Andres-Costa et al. 2017; Ma et al. 2020). The main sources of
pharmaceutical pollution are listed in Table 9.7.
Model-based simulation studies are being used to identify the sources of pollution. As one of the earliest studies, Mackay et al. (1996) described the first strategy
for environmental fate modelling. Basically, the process of understanding the fate of
the chemical of interest involves the collection and critical assessment of physicochemical properties such as molecular weight, vapour pressure, solubility in water,
K ow and pK a values. These data are required to characterise the pollutants and
adaptation of a suitable model for proper simulations. Today, a variety of model
approaches are available for environmental risk modelling of polar pharmaceutical
and personal care products in the environment. For detailed information, the interested reader is referred to the following review articles (Liebig et al. 2006; GonzalezGil et al. 2018; Cho et al. 2019; Gonzalez Garcia et al. 2019; Miller et al. 2019; Yuan
et al. 2019; Zillien et al. 2019; Pouzol et al. 2020).
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9 Source Characterisation and Contamination
detected in many environmental samples taken in highly industrialised countries in
wastewater and surface waters, and they are thus classified as emerging pollutants.
However, it was generally assumed that in developing countries the “classical”
pesticides of the first and second generation are prevailing in all environmental
compartments. But meanwhile, the working group of Hühnerfuss presented evidence that this assumption has to be modified considerably (Scheurell et al. 2013,
2014). In Karachi, Pakistan, surface water samples were collected during two
campaigns in December 2006 and April 2007 from the Malir River, the Lyari
River (the two major rivers flowing through Karachi), in the mangrove lagoon,
which is part of Karachi harbour receiving effluents from the central parts of the
city. Additional samples were taken from an open drainage canal system (Korangi
drain) receiving untreated residential and industrial effluents as well as wash-off and
rainwater from the Landhi residential district and from the end of a pipe eluting
waste waters from the district of Clifton across the beach into the Arabian Sea. A
total of 768 fractions from 32 samples were screened for their ecotoxicological
relevance by the luminescent bacteria test. The samples originate from all parts of
the drinking water circuit, including the sources (ground water and surface water),
distribution, processing and tapping points as well as wastewater. The determined
pollution status indicates the alarming condition of the drinking water circuit.
However, contrary to our expectation, no “classical” pesticides of the first and
second generations were prevailing. The waste and surface waters of the city area
of Karachi were severely contaminated with pharmaceuticals and industrial
chemicals (Scheurell et al. 2013, 2014). It is interesting to note that the high
concentrations of the parent compounds and their transformation products allowed
the determination of the molecular structure of several “new” environmental metabolites (Scheurell et al. 2013, 2014). For example, as mefenaminic acid was found in
all environmental water samples in Karachi, the respective transformation product
3-hydroxy-mefenaminic acid was ubiquitously identified and verified by
GC/MS. Further examples of thus far unknown chiral transformation products of
pharmaceuticals are given in related reports (Hühnerfuss 2000; Selke et al. 2010;
Scheurell et al. 2014; Andres-Costa et al. 2017; Ma et al. 2020). The main sources of
pharmaceutical pollution are listed in Table 9.7.
Model-based simulation studies are being used to identify the sources of pollution. As one of the earliest studies, Mackay et al. (1996) described the first strategy
for environmental fate modelling. Basically, the process of understanding the fate of
the chemical of interest involves the collection and critical assessment of physicochemical properties such as molecular weight, vapour pressure, solubility in water,
K ow and pK a values. These data are required to characterise the pollutants and
adaptation of a suitable model for proper simulations. Today, a variety of model
approaches are available for environmental risk modelling of polar pharmaceutical
and personal care products in the environment. For detailed information, the interested reader is referred to the following review articles (Liebig et al. 2006; GonzalezGil et al. 2018; Cho et al. 2019; Gonzalez Garcia et al. 2019; Miller et al. 2019; Yuan
et al. 2019; Zillien et al. 2019; Pouzol et al. 2020).
266
9 Source Characterisation and Contamination