Toxicity of nanoparticles on aquatic organisms. It is a wide field that covers exposure to effect vary with organisms to organisms and nanoparticles to nanoparticles. Herewith some papers are discussed about their effects.
3. The toxicity of ENPs to organisms in the aquatic environment is
governing by
Exposure media
Size and surface area
Surface chemistry
Shape
Concentration
5. NPs can enter into aquatic from
(i) waste water treatment plants effluents,
(ii) direct use (e.g., application of NPs-containing paintings
on boats), and
(iii) deposition from the air compartment.
These transformation including
dissolution,
aggregation and
sedimentation
6.
7. NANOTOXICITY TOWARDS AQUATIC
ORGANISMS
Generation of ROS –Production of free radicals
Omics endpoints – Tools to study the toxic
endpoints.
(Toxicogenomics, Metallomics,Proteomics)
8. Potential routes for the generation of ROS due to the presence of NPs. (1) Internalization
of NPs–ROS generation could occur due to the NPs dissolution inside the cells and/or due
to the NPs photocatalytic activity. (2) Dissolution of the NPs leads to an increase
concentration of metal ions in the media; some of these metals can also be uptake by the
organisms. (3) NPs and/or their surrounding coatings can adsorb/complex other metals
present in the media, being taken up by the cells. (4) Photocatalyti cactivity of the NPs in
the presence of UV and/or natural light.
9. BIOACCUMLATION
Aquatic nano-iron exposure caused dose-related accumulation of
iron particles in medaka intestine. (a) control, (b) 0.5 g L−1, (c) 5 g
L−1, (d) 50 g L−1 of nano-iron.
-Li et al.
11. DEVELOPMENTAL TOXICITY
Ag NPs- Dose-dependent developmental abnormality
Decreased eye dimension
-Myrzakhanova et al. (2013)
Au NPs- Hatch or developmental failure, abnormal
appearance and behavior
Smaller malpigmented eyes, axonal growth inhibition,
swimming behavior hypoactivity
- Shin et al. (2014),Kim (2013)
C60 NPs- Delayed zebrafish embryo and larval development,
decreased survival and hatching rates
- Zhu (2007)
12. GENOTOXICITY
Ag NPs- Entering the cell nucleus, and ROS initiated DNA
damage, increased lipid peroxidation (LPO) level and
decreased level of GSH, SOD and CAT, nuclear
fragmentation.
Taju et al. (2014)
CdS NPs- Genomic alteration, mitochondrial dysfunction
Ladhar et al. (2014)
IMMUNOTOXICITY
Ag NPs- Increase in general stress markers such as plasma
glucose and gill gene expression of heat shock protein 70
Farmen (2012)
13. SPECIFIC TOXICITY OF ENGINEERED
NANOPARTICLES TO TARGET ORGANS IN FISH
Respiratory Toxicity
Hepatotoxicity
Ocular and Visual System Toxicity
Hematotoxicity
14. Representative morphological abnormalities of medaka larvae exposed to
62.5–1000 μg L−1 Ag NPs during the embryonic stage. Embryos normally
developed in the control (A and B). However, various abnormalities were
observed in the Ag NP-treated groups.
DEVELOPMENTAL TOXICITY
15. Histopathological changes of the Ag NP-treated Japanese medaka larval eye.
(a) Control.
(b) (b) The thickness of inner nuclear cell layer (asterisk) and ganglion cell
layer (arrowhead) decreased in treated larvae.
(c) (c) The inner segments were missing in exposed larvae, instead of
thickened retinal pigment epithelium (asterisk).
Ocular and Visual System Toxicity
16. Test
species
NP
size (nm)
NP
concentration
Major
findings
Daphnia magna 20 250, 400, 500 mg/L Uptake efflux rate
lower for AgNPs than
for Ag+; assimilation
efficiency higher
for AgNP than Ag+
Daphnia magna 100 0–50 mg/L DNA strand breaks
were increased
following exposure
Daphnia magna 7; 10; 20 2.2 mg/L Loss of mobility and
fecundity
Daphnia exposed to AgNPs
EXPOSURE: 48h
Daphnids-Bio-indicators
17. Light microscope images of
daphnia exposed to AgNPs.
A: control,
B: live daphnia with pigmentation,
C and D: bubbles
visible under the carapace;
nanoparticles visible on the
antennae and body surface.
Caused abnormal swimming by the
D. magna.
Asghari et al.
OECD guideline number 202 (Daphnia Sp. acute immobilization test)
18. Test
species
NP
size (nm)
NP
concentration
Major
findings
Danio rerio 11.6 0.8 ppm Increase in D. rerio
mortalities;
abnormalities in
early life stages
Danio rerio 10–20 0.4; 4 ppm Defects in fin
regeneration and
penetration into
organelles and cell
nucleus
Danio rerio exposed to AgNPs
19. Optical images of normally developed (left)
and deformed
(right) D. rerio. A: tail/spinal cord,
B: cardiac;
C: head
Lee et al.
EXPOSURE: 10d
OBSERVATION:Increase in mortalities and abnormalities in early life stages as
well as mortalities with increasing NP concentration.
20. Adsorption and binding of
nanomaterials to external surface
of aquatic organisms
(A) Daphnia exposed to 6.5
mg/L nano-iron
(B) Harpacticoid copepods
exposed to 15 ppm aqua-C60 for
4 days.
(C) Fundulus heteroclitus
embroys exposed
to 10 ppm aqua-C60 for 6 days.
Oberdorster E, McClellan-Green P,. Haasch M. Ecotoxicology of
engineerednanomaterials.
23. D. magna individual in the acute experiments (a) exposed to 10 mgL−1
npTiO2, 48 h, the digestive system – gut was clearly see; (b) exposed to 50
mgL−1 npZnO, 48 h; (c) exposed to 50 mgL−1 np cocktail concentration, 48
h; (magnification 50x).
OBSERVATION: Decrease in body morphometry(change in body length and
width)
Acute Toxicity
Total:96 individuals
Replication :3
Exposure:48h
24. Chronic assay
Treatments are as same
as acute toxicity.
EXPOSURE:21days
REPLICATION:3
Assay started with
neonates
D. magna individual in chronic experiments (a) in the control group, 3rd-day; (b)
exposed to 0.5 mgL−1 npTiO2, 3rd-day; (c) exposed to 1.5 mgL−1 npTiO2, 4th-
day; (d) exposed to 0.5 mgL−1 npTiO2, 21st-day; npTiO2 was seen in digestion
system
25. Omics tools: New challenges in aquatic nanotoxicology (A case study)
TRANSCRIPTOMICS
29. CONCLUSION
Nanotoxicology is indeed a multidisciplinary field where the study of
the NPs physic, chemistry and biological impact is crucial for a
complete toxicological assessment.
Unfortunately, there is a lack of legislation controlling the
production, use and release of these materials to the environment,
and new NPs are commercialized every day without an appropriate
assessment about their impact in environment and human health.
The establishment of national and international laws regulating the
production of these materials is mandatory.
30. REFERENCES
Park, S-Y.; Choi, J. Geno- and ecotoxicity evaluation of silver
nanoparticles in freshwater crustacean Daphnia magna. Environ.
Eng. Res. 2010, 15(1), 23–27.
Baun, A.; Hartmann, N.B.; Grieger, K.; Kusk, K.O. Ecotoxicity of
engineered nanoparticles to aquatic invertebrates: a brief review
and recommendations for future toxicity testing. Ecotox. 2008, 17,
387–395.
Zhao, C-M.; Wang, W-E. Biokinetic uptake and efflux of silver
nanoparticles in Daphnia magna. Environ. Sci. Technol. 2010, 44,
7699–7704.
(Oberdorster E. et al., 2006; Templeton et al., 2006; Zhu Y. et al.,
2006a,b; Elias et al., 2007; Roberts et al., 2007; Zhu X.
et al., 2009).