Environmental exposure and effects of some micropollutants found in the Romanian surface water

Ecological risk assessment is required by the European norms to predict or evaluate the
effects of chemicals, which are discharged into the receiving ‘environment’. usually the aquatic
risk involves two major components: occurrence and hazard effects. In order to estimate the predicted exposure concentrations of chemicals in the water (PEC aquatic) and the predicted no-effect
concentration on organisms (PNEC aquatic), literature data collecting and laboratory testing data
were necessary. a ratio of PEC/PNEC < 1 indicated no aquatic risk and no future assessments is
deemed necessary. In the period of 2009–2013, within different national projects, our aquatic risk
studies has been initiated for some micropollutants, such as hazardous chemicals (4-chloroaniline,
1-chloro-4-nitrobenzene and 4-chloro-2-nitrotoluene), pesticides (azinphos-methyl and bentazone),
pharmaceuticals (diclophenac, acetaminophen, ketoprophen, indomethacin, naproxen, ibuprophen,
carbamazepine, caffeine, ciproflxacine and trimethoprim) and surfactants (benzenthonium chloride
and cocamidopropyl betaine). Several toxicity bioassays using the sensitivity of living organisms at
different trophic levels (fish, planktonic crustacean, green algae and different bacteria species) were
performed. The studied chemicals showed a relatively limited acute toxicity and generally the final
results have revealed insignificant or low risks on aquatic organisms. Two chemicals (ciproflxacin
and benzenthonium chloride) showed high environmental risk. The ranking organism sensitivity was
crustacean, bacteria and algae. The risk assessment studies were based on environmental concentrations detected in Romanian surface waters (Danube River, Danube Delta, Arges River, Mures River,
Ciorogarla River and Ghimbasel stream) comparatively with other international rivers.