those agents. This issue creates two main lines of scientific work: phytoremediation
and human health risk assessment. From the collected articles, only 12.5% of the
studies focused on phytoremediation [103–105], which shows a trend towards a
focus on edible plants for further human risk assessments. In that respect, the most
studied plant of the analysed studies was lettuce (Lactuca sativa) (29.65%), followed
by radish (12.96%) and cucumber (7.41%), which are all economically relevant
crops.
The duration of exposure in the collected studies varied between 6 h and 98 days;
some showed only single time point measurements (n ¼ 32) and others a time course
with multiple time points (n ¼ 22). Considering only single time points studies, in
71.9% of the cases, they tested a duration of at least 21 days. As it was mention
before, only studies with multiple collection time points with given concentrations in
nutrient media or soil at tested time points were used, to avoid overestimations of
BCFs. It is also necessary to be aware of studies where nutrient solutions or soils
were replenished/irrigated with solutions containing pharmaceuticals during the time
course of the experiment when no information about volume, concentration and
frequency of the added solution were mentioned to calculate the correct BCF. The
tested concentrations of pharmaceuticals varied between 100 ng/L and 200 mg/L. In
some studies, a single concentration was used, while in others, like Adeel and
co-workers [106], several concentrations were studied ranging from 100 ng/L to
10 mg/L.
Taking into account all conditions and limitations presented above, data from
selected publications was grouped and expressed as BCF and TF, according to the
chemical properties and the ionic status of the compounds and additionally separated
into trials done as hydroponic (a) and soil (b) experiments (Tables 1, 2, 3, 4, 5, and
6). Information is presented like this, because most of the concepts in the first part of
this chapter can only be directly related to experimental data with controlled and/or
few external interferences, as the hydroponic experiments. With the soil experiments, factors like the percentage of OM and even the soil constituents will interfere
in the analysis, especially when comparing different studies, but on the other hand,
the results will be closer to a realistic scenario.
The boxplots (designed using GraphPad Prism software, v 6.01) in Figs. 4, 5 and
6, which are showing the BCFs and TFs of the distribution of observations from
different studies as well as minimum, median and maximum values, were also
separated according to the ionic status of the compounds and the type of study
(hydroponic and soil experiments), as mentioned above. One study can include
several observations (shown by dots) by testing various conditions like duration,
concentration or pH. Therefore, boxplots (Figs. 4, 5 and 6) provide a detailed picture
of summarized data in Tables 1, 2, 3, 4, 5 and 6, and exceptions can be detected
easily and considered for discussion to secure the validity of BCF and TF average
values.
For the uptake and translocation of organic compounds, the molar mass with high
possibility only plays a role for big molecules with molar mass !1,000 g/mol [21] or
as hypothesized for pharmaceuticals with molar mass !400 g/mol [20]. None of the
studied pharmaceuticals was !1,000 g/mol, and only eight of them can be
Uptake and Translocation of Pharmaceuticals in Plants:. . .
119
and human health risk assessment. From the collected articles, only 12.5% of the
studies focused on phytoremediation [103–105], which shows a trend towards a
focus on edible plants for further human risk assessments. In that respect, the most
studied plant of the analysed studies was lettuce (Lactuca sativa) (29.65%), followed
by radish (12.96%) and cucumber (7.41%), which are all economically relevant
crops.
The duration of exposure in the collected studies varied between 6 h and 98 days;
some showed only single time point measurements (n ¼ 32) and others a time course
with multiple time points (n ¼ 22). Considering only single time points studies, in
71.9% of the cases, they tested a duration of at least 21 days. As it was mention
before, only studies with multiple collection time points with given concentrations in
nutrient media or soil at tested time points were used, to avoid overestimations of
BCFs. It is also necessary to be aware of studies where nutrient solutions or soils
were replenished/irrigated with solutions containing pharmaceuticals during the time
course of the experiment when no information about volume, concentration and
frequency of the added solution were mentioned to calculate the correct BCF. The
tested concentrations of pharmaceuticals varied between 100 ng/L and 200 mg/L. In
some studies, a single concentration was used, while in others, like Adeel and
co-workers [106], several concentrations were studied ranging from 100 ng/L to
10 mg/L.
Taking into account all conditions and limitations presented above, data from
selected publications was grouped and expressed as BCF and TF, according to the
chemical properties and the ionic status of the compounds and additionally separated
into trials done as hydroponic (a) and soil (b) experiments (Tables 1, 2, 3, 4, 5, and
6). Information is presented like this, because most of the concepts in the first part of
this chapter can only be directly related to experimental data with controlled and/or
few external interferences, as the hydroponic experiments. With the soil experiments, factors like the percentage of OM and even the soil constituents will interfere
in the analysis, especially when comparing different studies, but on the other hand,
the results will be closer to a realistic scenario.
The boxplots (designed using GraphPad Prism software, v 6.01) in Figs. 4, 5 and
6, which are showing the BCFs and TFs of the distribution of observations from
different studies as well as minimum, median and maximum values, were also
separated according to the ionic status of the compounds and the type of study
(hydroponic and soil experiments), as mentioned above. One study can include
several observations (shown by dots) by testing various conditions like duration,
concentration or pH. Therefore, boxplots (Figs. 4, 5 and 6) provide a detailed picture
of summarized data in Tables 1, 2, 3, 4, 5 and 6, and exceptions can be detected
easily and considered for discussion to secure the validity of BCF and TF average
values.
For the uptake and translocation of organic compounds, the molar mass with high
possibility only plays a role for big molecules with molar mass !1,000 g/mol [21] or
as hypothesized for pharmaceuticals with molar mass !400 g/mol [20]. None of the
studied pharmaceuticals was !1,000 g/mol, and only eight of them can be
Uptake and Translocation of Pharmaceuticals in Plants:. . .
119