Poster Presentation Society of Environmental Toxicology and Chemistry Australasia 2021

Influence of nanomaterial ageing and presence of abiotic factors on effects of biogenic phosphorus-based nanomaterials on zebrafish embryos (#186)

Ayushi Priyam 1 2 , Pushplata Singh 2 , Luis Afonso 1 , Aaron Schultz 1
  1. Deakin University, Geelong, VICTORIA, Australia
  2. Sustainable agriculture division, The Energy and Resources Institute , New Delhi , Delhi, India

The phosphorus (P) -based nanomaterials (NMs) are now suggested to be applied as nanofertilizers to address P fertilizing issues in agricultural soils. These are expected to enter water streams on application to agricultural fields from runoff events. Once in the environment, these may interact with a variety of abiotic factors such as natural organic matter and sunlight. These NMs may also reside in the environment and age in those conditions. Thus, it becomes critical to assay their consequent effects on aquatic organisms. In this study, the effects of multiple types of P-based nanomaterials (NMs) on zebrafish embryos were examined. The study involved variants of biologically and chemically synthesized nanohydroxyapatites (nHAPs) and another NM, nanophosphorus (nP), biosynthesized from bulk rock phosphate (RP). These NMs differed most prominently in shape and size. This study investigated both lethal and sub-lethal endpoints in zebrafish embryos up to 96 h post-fertilization (hpf) under the combination of humic acid, simulated sunlight (UV) and NM exposures. Further, these NMs were aged for 3 months in environmentally relevant aquaculture conditions and were tested for any toxic effects in dose dependent manner. The effects of each of the different NM exposures on zebrafish embryos were assayed using survival, hatching, developmental deformities, and heart rate as the key endpoints. From this study it has been observed that nHAP and nP under environmentally relevant conditions do not cause severe detrimental effects on development and cardiovascular system of zebrafish embryos. No observed LD50was obtained up to a dose of 500 μg.mL-1 for any of the NMs tested. Overall, the results will provide important information on the behaviour of biologically synthesized nanoagriinputs under ecologically realistic conditions and will provide the scope for the future use and application of biogenic nHAP and nP as safe nanofertilizers.