suggested. The level of toxicity of these compounds and other potential toxic drugs
should be determined, after which regulation of maximum permissible levels in
treated wastewater for irrigation could be established.
In the environment, the toxicity of drugs has been evaluated in soil biota.
Lumbricus terrestris has appeared as a good alternative to the Eisenia spp. models
in acute toxicity testing and as a good bioindicator in soil toxicity assessment.
Research has primarily centered on evaluating the effects of veterinary pharmaceuticals (antibiotics) with the most common end-points considering survival, reproduction, and alterations in behavior. More research, characterizing the risk using a
wider variety of pharmaceuticals under environmentally relevant exposure scenarios
is urgently needed by incorporating “omic” disciplines as effective and reliable
biomarkers, as well as recent technical advances in metabolite identification into
toxicity evaluation. As far as phytotoxicity of PhACs is concerned, it is important to
highlight that the majority of studies that have elucidated their effects on plants have
used high exposure concentrations into a growth medium, which do not resemble
in vivo situations occurring in the natural soil environment. More recently, research
has started to explore the potential for sublethal effects or changes in key plant
parameters at lower, environmentally relevant concentrations. One promising
approach is the measurement of the alteration of plant hormones concentrations
because these play an integral role in plant growth processes as well as in biotic and
abiotic stress responses and because hormone-triggered changes may be the basis for
more long-term visual phytotoxic responses. The assessment of the ecotoxicity of
PhACs on soil microorganisms is lagging behind the risk assessment procedures for
terrestrial macroorganisms, despite their well-documented pivotal role in ecosystem
functioning. We are still missing several pieces of the puzzle including (1) a
meaningful tiered approach, (2) well-defined experimental protocols, and (3) functional microbial groups, which can act as bioindicators. For pesticides regulation,
key functional microbial groups were identified as potential microbial indicators
such as arbuscular mycorrhizal fungi (AMF) due to their key role in plant nutrition
and ammonia-oxidizing microorganisms (AOM) due to their involvement in the
cycling of nitrogen. However, similar work has not been conducted for PhACs yet.
5 Methods for the Analysis of PhACs in Soil-Crops Systems
In the past, research has focused on the analysis and determination of PhACs in
particular in waste or surface water. Only recently, due to the growing demand for
water in the agricultural sector, the attention of the scientific community has started
to shift to the effects of emerging contaminants in soil and plants. Therefore, the big
challenge is to identify chemicals that could potentially have harmful effects on
human health, terrestrial and aquatic organisms, and ecosystems.
The main problem concerns the search for more efficient and more accurate
analytical methods, as well as the need to obtain reliable analytical information on
a greater number of known chemical compounds that may be present in the tested
Conclusions and Future Perspectives
529
should be determined, after which regulation of maximum permissible levels in
treated wastewater for irrigation could be established.
In the environment, the toxicity of drugs has been evaluated in soil biota.
Lumbricus terrestris has appeared as a good alternative to the Eisenia spp. models
in acute toxicity testing and as a good bioindicator in soil toxicity assessment.
Research has primarily centered on evaluating the effects of veterinary pharmaceuticals (antibiotics) with the most common end-points considering survival, reproduction, and alterations in behavior. More research, characterizing the risk using a
wider variety of pharmaceuticals under environmentally relevant exposure scenarios
is urgently needed by incorporating “omic” disciplines as effective and reliable
biomarkers, as well as recent technical advances in metabolite identification into
toxicity evaluation. As far as phytotoxicity of PhACs is concerned, it is important to
highlight that the majority of studies that have elucidated their effects on plants have
used high exposure concentrations into a growth medium, which do not resemble
in vivo situations occurring in the natural soil environment. More recently, research
has started to explore the potential for sublethal effects or changes in key plant
parameters at lower, environmentally relevant concentrations. One promising
approach is the measurement of the alteration of plant hormones concentrations
because these play an integral role in plant growth processes as well as in biotic and
abiotic stress responses and because hormone-triggered changes may be the basis for
more long-term visual phytotoxic responses. The assessment of the ecotoxicity of
PhACs on soil microorganisms is lagging behind the risk assessment procedures for
terrestrial macroorganisms, despite their well-documented pivotal role in ecosystem
functioning. We are still missing several pieces of the puzzle including (1) a
meaningful tiered approach, (2) well-defined experimental protocols, and (3) functional microbial groups, which can act as bioindicators. For pesticides regulation,
key functional microbial groups were identified as potential microbial indicators
such as arbuscular mycorrhizal fungi (AMF) due to their key role in plant nutrition
and ammonia-oxidizing microorganisms (AOM) due to their involvement in the
cycling of nitrogen. However, similar work has not been conducted for PhACs yet.
5 Methods for the Analysis of PhACs in Soil-Crops Systems
In the past, research has focused on the analysis and determination of PhACs in
particular in waste or surface water. Only recently, due to the growing demand for
water in the agricultural sector, the attention of the scientific community has started
to shift to the effects of emerging contaminants in soil and plants. Therefore, the big
challenge is to identify chemicals that could potentially have harmful effects on
human health, terrestrial and aquatic organisms, and ecosystems.
The main problem concerns the search for more efficient and more accurate
analytical methods, as well as the need to obtain reliable analytical information on
a greater number of known chemical compounds that may be present in the tested
Conclusions and Future Perspectives
529