PUBLICATION

Embryotoxicity of ozonated diclofenac, carbamazepine, and oxazepam in zebrafish (Danio rerio)

Authors
Pohl, J., Ahrens, L., Carlsson, G., Golovko, O., Norrgren, L., Weiss, J., Örn, S.
ID
ZDB-PUB-190316-13
Date
2019
Source
Chemosphere   225: 191-199 (Journal)
Registered Authors
Norrgren, Leif
Keywords
Developmental toxicity, OBP, Ozonation, Ozonation by-products, Ozone removal efficiency, Pharmaceuticals
MeSH Terms
  • Animals
  • Carbamazepine/chemistry
  • Carbamazepine/toxicity*
  • Diclofenac/chemistry
  • Diclofenac/toxicity*
  • Oxazepam/chemistry
  • Oxazepam/toxicity*
  • Ozone/chemistry*
  • Sewage/chemistry
  • Water Pollutants, Chemical/chemistry
  • Water Pollutants, Chemical/toxicity*
  • Zebrafish/embryology*
PubMed
30875502 Full text @ Chemosphere
Abstract
Pharmaceutical residues are polluting the surface water environments worldwide. Sewage and wastewater treatment, therefore, needs to be improved in order to remove pharmaceutical residues from the effluent. One such treatment improvement is effluent ozonation. Even though ozonation has proven to be very efficient in reducing pharmaceutical parent compound concentrations in wastewater effluents, much remains unclear regarding potentially toxic ozonation by-product (OBP) formation. In this study, we sought to elucidate the aquatic toxicity of ozonated pharmaceuticals in zebrafish (Danio rerio) embryos in a static 144 h post fertilization (hpf) fish embryotoxicity (ZFET) assay. Three pharmaceuticals commonly detected in wastewater effluents, i.e. carbamazepine, diclofenac, and oxazepam, were selected for testing. Toxicity was assessed before and after 1 min ozonation (0.053 mg L-1 peak O3 concentration) and 10 min ozonation (0.147 mg L-1 peak O3 concentration). Chemical analysis showed that carbamazepine and diclofenac were largely removed by ozone (90 ± 11% and 97 ± 3.8%), whereas oxazepam was removed to a lesser extent (19 ± 5.7%). The ZFET assay revealed diverging toxicities. Diclofenac embryotoxicity decreased with increasing ozonation. Oxazepam did not cause embryotoxicity in the ZFET assay either pre- or post ozonation, but larvae swimming activity was affected at 144 hpf. Carbamazepine embryotoxicity, on the other hand, increased with increasing ozonation. Chemical analysis showed the formation of two OBPs (carbamazepine-10,11-epoxide and 10,11-dihydrocarbamazepine), possibly explaining the increased embryotoxicity. The results of this study highlight the importance of new chemical and toxicological knowledge regarding the formation of OBPs in post-ozonated effluents.
Genes / Markers
Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping