1. Drug consumption is increasing owing to demographic growth, aging population,
and improved access to medication. The process is ubiquitous on space and
continuous on time and extends to some thousands of available drugs.
2. Depending on each specific compound and characteristics of the wastewater
treatment, their elimination may be not complete. Although specific tertiary
treatment steps may be added, an additional technology increases the economic
cost of the waste treatment.
3. Even though many drugs are degraded, their continuous input into the environment makes them to behave as “pseudo-persistent.”
4. Drugs are, by design, biologically active compounds, targeted to specific organisms, and having modes of action. Possible side effects on other unintentionally
non-targeted exposed organisms living in the receiving ecosystem cannot be
ruled out.
5. In addition to long-term ecotoxicity effects, there is a human health concerns
about antimicrobials (antibiotics, antifungals), whose occurrence in the environment has been proved to promote the development of resistance genes (antimicrobial resistance genes, ARG).
6. The “cocktail” of many drugs, metabolites, and transformation products may
have unexpected and unpredictable mixture interaction effects (i.e., synergistic,
antagonistic, etc.) on environmental wildlife.
7. Last but not least, the anthropogenic water cycle includes the safe supply of
drinking water to the population. The occurrence of drugs residues in drinking
water may pose a risk in human health; therefore their presence must be
minimized.
Altogether, it is recognized that the occurrence of drugs in the environment is not
devoid of risk and there is a need for incorporating environmental safety aspects into
existing regulatory frameworks. In this regard, two broad areas of legislation may be
highlighted, namely, (1) the registration process of drugs and (2) the occurrence of
drugs in the environment and more specifically in the aquatic environment. Here we
will briefly review the current status of both aspects of drug legislation in the
European Union.
(a) Regulation of Drugs in the Aquatic Environment
The preservation of the aquatic environment, either surface (marine and fresh) or
groundwater in Europe is essentially regulated by the Water Framework Directive
(WFD) (Directive 2000/60/EC) [14] and derived pieces of legislation. In that
context, to achieve the good status of European water bodies, both the good
ecological and chemical status requirements must be fulfilled. For the latter, environmental levels must be in compliance with the environmental quality standards
(EQS) of the so called priority substances, whose EQS were set up in the WFD
daughter directives (Directive 2008/105/EC amended by Directive 2013/39/EU)
[15, 16]. Currently, the list of priority substances constituted 45 chemical species.
However, the “list of priority substances” is subjected to periodic revision, meaning
that it is open to the incorporation of new candidate substances. To do so Directive
The Journey of Human Drugs from Their Design at the Bench to Their Fate in Crops
13
and improved access to medication. The process is ubiquitous on space and
continuous on time and extends to some thousands of available drugs.
2. Depending on each specific compound and characteristics of the wastewater
treatment, their elimination may be not complete. Although specific tertiary
treatment steps may be added, an additional technology increases the economic
cost of the waste treatment.
3. Even though many drugs are degraded, their continuous input into the environment makes them to behave as “pseudo-persistent.”
4. Drugs are, by design, biologically active compounds, targeted to specific organisms, and having modes of action. Possible side effects on other unintentionally
non-targeted exposed organisms living in the receiving ecosystem cannot be
ruled out.
5. In addition to long-term ecotoxicity effects, there is a human health concerns
about antimicrobials (antibiotics, antifungals), whose occurrence in the environment has been proved to promote the development of resistance genes (antimicrobial resistance genes, ARG).
6. The “cocktail” of many drugs, metabolites, and transformation products may
have unexpected and unpredictable mixture interaction effects (i.e., synergistic,
antagonistic, etc.) on environmental wildlife.
7. Last but not least, the anthropogenic water cycle includes the safe supply of
drinking water to the population. The occurrence of drugs residues in drinking
water may pose a risk in human health; therefore their presence must be
minimized.
Altogether, it is recognized that the occurrence of drugs in the environment is not
devoid of risk and there is a need for incorporating environmental safety aspects into
existing regulatory frameworks. In this regard, two broad areas of legislation may be
highlighted, namely, (1) the registration process of drugs and (2) the occurrence of
drugs in the environment and more specifically in the aquatic environment. Here we
will briefly review the current status of both aspects of drug legislation in the
European Union.
(a) Regulation of Drugs in the Aquatic Environment
The preservation of the aquatic environment, either surface (marine and fresh) or
groundwater in Europe is essentially regulated by the Water Framework Directive
(WFD) (Directive 2000/60/EC) [14] and derived pieces of legislation. In that
context, to achieve the good status of European water bodies, both the good
ecological and chemical status requirements must be fulfilled. For the latter, environmental levels must be in compliance with the environmental quality standards
(EQS) of the so called priority substances, whose EQS were set up in the WFD
daughter directives (Directive 2008/105/EC amended by Directive 2013/39/EU)
[15, 16]. Currently, the list of priority substances constituted 45 chemical species.
However, the “list of priority substances” is subjected to periodic revision, meaning
that it is open to the incorporation of new candidate substances. To do so Directive
The Journey of Human Drugs from Their Design at the Bench to Their Fate in Crops
13