1.1 Contaminants of Emerging Concern
The definition of “Contaminant of emerging concern” (CEC) considers three types
of CEC [6]: (1) totally new chemical or material that have not been previously
screened in the environment; (2) existing substance whose information about
environmental impact and toxicity is lacking; (3) substances, with known environmental impact and toxicity, but with previously unidentified adverse effects.
The CEC, as the other pollutants, can be analysed taking into account the exposure
route, the fate of pollutant and the bio-monitoring capability. A recent survey
(EUROSTAT) has highlighted that almost the half of chemical production is
constituted by CEC, including different products ranging from pesticides to
nanoparticles from pharmaceuticals to micro-plastics. They can originated by all
human activities: industrial production, agriculture, health and life-styles. It is
important to underline that CEC could be derived from transformation and
degradation of other chemicals not only toxic. The capability to efficiently
screening and remove CEC released in water, is important to guarantee a good
quality of water for all human need [7]. Availability of drinking water is becoming
a global concern both for quantity and quality. It is particularly sensitive to CEC
and micro-contaminants. The adverse impact is not only on human health however
also on the whole ecosystem. There are five basic qualitative characteristics that one
have to consider; (1) persistence; (2) mobility; (3) bioavailability; (4) bioaccumulation; (5) bio-amplification. The monitoring and risk assessment for these compounds is complex because it is necessary to take into account different features
such as chemical-physics properties of the compound and the geo-climatological
characteristics of the environmental compartment in which the pollutant is release.
The resistance (persistence) to degrading agents, abiotic or biotic, is a pivotal
feature to consider; another characteristics is the capability of a pollutant to be
vehiculate, far from its origin, with a low level of compound absorbed by solid
particles. The monitoring of CEC in the water follow standard sampling protocols
for the different water resources or for bottled beverages. The sludge, produced by
wastewater treatment plants, could contain high levels of more persistent pollutants
including CEC. The employ of these sludge, as fertilizer, in agriculture can have an
impact also on soil quality altering, for instance, the microbial and fungal communities or increase the bioaccumulation of toxicants in vegetables. The personal
care and pharmaceutical products (PCPPs) and pesticide are very particular CEC
contaminants because they are designed to have a biological activity. The exposure
to PCPPs is generally consists of low doses of pollutant, for this reason large
fraction of them is lacking of sufficient toxicological data to formulate an appropriate regulation. PCPPs are characterised by wide heterogeneity of structures,
chemical-physics and biological activities. Furthermore not only the original
compound can exert a toxic effect but also its metabolite. Some studies carried out
on ibuprofen [8] have underlined that abiotic and biotic degradation of ibuprofen
originate a toxic metabolite (4-chlorphenol). The PCPPs seem to rather persistent in
water and soil and their impact on ecosystems is not yet clearly established. These
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The definition of “Contaminant of emerging concern” (CEC) considers three types
of CEC [6]: (1) totally new chemical or material that have not been previously
screened in the environment; (2) existing substance whose information about
environmental impact and toxicity is lacking; (3) substances, with known environmental impact and toxicity, but with previously unidentified adverse effects.
The CEC, as the other pollutants, can be analysed taking into account the exposure
route, the fate of pollutant and the bio-monitoring capability. A recent survey
(EUROSTAT) has highlighted that almost the half of chemical production is
constituted by CEC, including different products ranging from pesticides to
nanoparticles from pharmaceuticals to micro-plastics. They can originated by all
human activities: industrial production, agriculture, health and life-styles. It is
important to underline that CEC could be derived from transformation and
degradation of other chemicals not only toxic. The capability to efficiently
screening and remove CEC released in water, is important to guarantee a good
quality of water for all human need [7]. Availability of drinking water is becoming
a global concern both for quantity and quality. It is particularly sensitive to CEC
and micro-contaminants. The adverse impact is not only on human health however
also on the whole ecosystem. There are five basic qualitative characteristics that one
have to consider; (1) persistence; (2) mobility; (3) bioavailability; (4) bioaccumulation; (5) bio-amplification. The monitoring and risk assessment for these compounds is complex because it is necessary to take into account different features
such as chemical-physics properties of the compound and the geo-climatological
characteristics of the environmental compartment in which the pollutant is release.
The resistance (persistence) to degrading agents, abiotic or biotic, is a pivotal
feature to consider; another characteristics is the capability of a pollutant to be
vehiculate, far from its origin, with a low level of compound absorbed by solid
particles. The monitoring of CEC in the water follow standard sampling protocols
for the different water resources or for bottled beverages. The sludge, produced by
wastewater treatment plants, could contain high levels of more persistent pollutants
including CEC. The employ of these sludge, as fertilizer, in agriculture can have an
impact also on soil quality altering, for instance, the microbial and fungal communities or increase the bioaccumulation of toxicants in vegetables. The personal
care and pharmaceutical products (PCPPs) and pesticide are very particular CEC
contaminants because they are designed to have a biological activity. The exposure
to PCPPs is generally consists of low doses of pollutant, for this reason large
fraction of them is lacking of sufficient toxicological data to formulate an appropriate regulation. PCPPs are characterised by wide heterogeneity of structures,
chemical-physics and biological activities. Furthermore not only the original
compound can exert a toxic effect but also its metabolite. Some studies carried out
on ibuprofen [8] have underlined that abiotic and biotic degradation of ibuprofen
originate a toxic metabolite (4-chlorphenol). The PCPPs seem to rather persistent in
water and soil and their impact on ecosystems is not yet clearly established. These
Computational Design of Nucleic Acid-Based Bioreceptor …
215