7 Pharmaceuticals in Crops Irrigated with Treated
Wastewater
With freshwater becoming increasingly scarce, the water crisis is turning into a
political, economic and social issue. Hence, the growing pressure on water resources
forces to look for alternative sources of freshwater. In this sense, the reliance on
extraction of freshwater, surface water, and groundwater can be diminished by using
reclaimed wastewater. The reuse of wastewater is a fundamental requirement for the
management of water resources, although globally there is a lack of legislation on
the minimum requirements for water quality and monitoring for water reclamation.
In view of the high content of nutrients such as phosphorus and nitrogen, treated
wastewater lends itself readily for irrigation purposes in agriculture. Furthermore, by
reducing the need for additional mineral fertilizer applications, water reclamation
contributes to the promotion of the circular economy by recovering nutrients and
saving money. The use of wastewater in agriculture for irrigation and fertilization
purposes has ancient origins that are lost over time [64]. Currently, Israel uses
around 50% of its treated wastewater for its agricultural sector. However, before
authorizing the use of recycled water in agriculture on a global scale, it would be
advisable to develop minimum requirements to reduce the possible human and
environmental risk resulting from this type of practice, as well as the uncontrolled
introduction of exogenous contaminants into the agricultural ecosystem [65]. Today
there are concerns remaining about the safety of irrigation with treated wastewater
from conventional wastewater treatments plants because it contains various contaminants among them pharmaceuticals and their metabolites. Soil irrigated with treated
wastewater will therefore be exposed to these xenobiotics. Besides, crops and soil
fauna such as earthworms are sensitive to environmental pollutants contributing
directly or indirectly to their degradation. Not surprisingly, the use of treated
wastewater represents the main source of drugs in arable land, in agreement with
the agricultural water management systems [66]. Therefore, in real crops, pharmaceuticals and their metabolites can be retained in the soil, metabolized in earthworms, directly taken up by crops, or translocated from soil to plant tissues above the
ground.
8 Uptake, Distribution, and Metabolism of PhACs in Crops
Studies on the absorption, translocation, and metabolism of PhACs are still very
scarce or limited to studies under controlled or laboratory conditions, while studies
in the natural environment or field conditions are minimal. Experiments in greenhouse or laboratory conditions such as hydroponic systems are usually performed
with a period of controlled light, relative humidity, temperature, etc.
The uptake of PhACs by crops is related to growth conditions, soil properties,
plant biology, exposure medium, and compound properties. The properties of
The Journey of Human Drugs from Their Design at the Bench to Their Fate in Crops
19
Wastewater
With freshwater becoming increasingly scarce, the water crisis is turning into a
political, economic and social issue. Hence, the growing pressure on water resources
forces to look for alternative sources of freshwater. In this sense, the reliance on
extraction of freshwater, surface water, and groundwater can be diminished by using
reclaimed wastewater. The reuse of wastewater is a fundamental requirement for the
management of water resources, although globally there is a lack of legislation on
the minimum requirements for water quality and monitoring for water reclamation.
In view of the high content of nutrients such as phosphorus and nitrogen, treated
wastewater lends itself readily for irrigation purposes in agriculture. Furthermore, by
reducing the need for additional mineral fertilizer applications, water reclamation
contributes to the promotion of the circular economy by recovering nutrients and
saving money. The use of wastewater in agriculture for irrigation and fertilization
purposes has ancient origins that are lost over time [64]. Currently, Israel uses
around 50% of its treated wastewater for its agricultural sector. However, before
authorizing the use of recycled water in agriculture on a global scale, it would be
advisable to develop minimum requirements to reduce the possible human and
environmental risk resulting from this type of practice, as well as the uncontrolled
introduction of exogenous contaminants into the agricultural ecosystem [65]. Today
there are concerns remaining about the safety of irrigation with treated wastewater
from conventional wastewater treatments plants because it contains various contaminants among them pharmaceuticals and their metabolites. Soil irrigated with treated
wastewater will therefore be exposed to these xenobiotics. Besides, crops and soil
fauna such as earthworms are sensitive to environmental pollutants contributing
directly or indirectly to their degradation. Not surprisingly, the use of treated
wastewater represents the main source of drugs in arable land, in agreement with
the agricultural water management systems [66]. Therefore, in real crops, pharmaceuticals and their metabolites can be retained in the soil, metabolized in earthworms, directly taken up by crops, or translocated from soil to plant tissues above the
ground.
8 Uptake, Distribution, and Metabolism of PhACs in Crops
Studies on the absorption, translocation, and metabolism of PhACs are still very
scarce or limited to studies under controlled or laboratory conditions, while studies
in the natural environment or field conditions are minimal. Experiments in greenhouse or laboratory conditions such as hydroponic systems are usually performed
with a period of controlled light, relative humidity, temperature, etc.
The uptake of PhACs by crops is related to growth conditions, soil properties,
plant biology, exposure medium, and compound properties. The properties of
The Journey of Human Drugs from Their Design at the Bench to Their Fate in Crops
19