A new test system for unraveling the effects of soil components on the uptake and toxicity of silver nanoparticles (NM-300K) in simulated pore water

Filser

2020

Environ Sci Eur

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Background Toxicity of silver nanoparticles (AgNP) has been studied frequently due to a rise in application in various products. Various studies on AgNP toxicity with terrestrial and aquatic organisms confirmed their negative effects. In our previous experiments, strong variability was observed in the reproduction of Collembola (Folsomia candida) in different repeats. To investigate the effects of silver on the reproduction of Folsomia candida, they were exposed in laboratory-controlled conditions to AgNP and silver nitrate (AgNO3) at a concentration of 30 mg/kg dry soil for 28 days and compared to controlled individuals not exposed to silver. We repeated reproduction tests on the toxicity of silver to Folsomia candida four times throughout one year (April, July, October and January) in order to explore the temporal variability of their outcome. Results While adult survival was similar in all treatments and seasons, reproduction in the control increased from April to October. Significantly lower reproduction was found in January with only 385–424 juveniles per vessel, compared to 504–633 individuals in other months. Strong toxic effects of both silver treatments were observed in July, April and October. However, AgNP showed no toxic effects on the reproduction of F. candida in January. The relative toxicity of both substances varied between single experiments: AgNP were more toxic than AgNO3 in April and July, and less toxic in October and January. Conclusion These findings indicate that the reproduction of F. candida in the control had a significant effect on the results of the toxicology experiments. Moreover, we demonstrated the reproductive toxicity of AgNP in soil at a much lower concentration than reported thus far. Therefore, to guarantee reliability and reproducibility, we recommend to disregard any test results where the reproduction rate of F. candida in the control is significantly different from the average in the respective laboratory, even if the validity criteria of the test are met.

Section: Discussionsupporting

confidence: 92%

Section: Discussionsupporting

confidence: 86%

Low concentration effects and different outcome in repeated reproduction tests with silver nanoparticles, silver nitrate and Folsomia candida (Collembola)

Filser

2020

Environ Sci Eur

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“…For NM-300K, an effect of the organic dispersion can be excluded, because tests have been made in advance to ensure that the dispersion showed no toxic effect of on the reproduction of F. candida (X. Zhang, unpublished data). McKee et al (2019) studied the dispersion of NM-300K in OECD soil pore water and found that the dispersion caused significant immobilization of F. candida at 10 mg L -1 whereas no toxic effect occurred at mg L -1 [27]. This is in line with our findings.…”

Section: Discussionsupporting

confidence: 92%

Seasonal effects on the outcome of reproduction tests with silver nanoparticles, silver nitrate and the Collembola Folsomia candida

Filser

2020

Preprint

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Background Toxicity of silver nanoparticles (AgNP) is increasingly studied due to a rise in application in various products. Various studies on AgNP toxicity with terrestrial and aquatic organisms confirmed their negative effects. In our previous experiments, strong variability was observed in the reproduction of Collembola in different seasons. To investigate the effects of silver nanoparticles (AgNP) on the reproduction of Collembola in different seasons, Folsomia candida were exposed to AgNP and silver nitrate (AgNO 3 ) at a concentration of 30 mg/kg dry soil for 28 days. The reproduction tests were repeated during different seasons throughout one year in order to assess if animals’ sensitivity varied with the season. Results Significantly lower reproduction was found in the control in winter with only 101 (± 7) juveniles per adult, compared to 126-158 individuals in other seasons. Strong toxic effects (inhibition of reproduction by up to 50%) were observed during summer, spring and autumn in both treatments. However, AgNP showed no toxic effects on the reproduction of F. candida in winter. The relative toxicity of both substances varied with the seasons: AgNP were more toxic than AgNO 3 in spring and summer, and less toxic in autumn and winter. Conclusion These findings indicate that seasonal effects on the reproduction of Folsomia candida are significant. Moreover, we demonstrated the reproductive toxicity of AgNP in soil at a much lower concentration than reported thus far. These effects can mainly be attributed to soil conditions, which raises concern whether these commonly used test substrates are really protective.

“…For NM-300K, an effect of the organic dispersion can be excluded, because tests have been made in advance to ensure that the dispersion showed no toxic effect of on the reproduction of F. candida (X. Zhang, unpublished data). McKee et al (2019) studied the dispersion of NM-300K in OECD soil pore water and found that the dispersion caused signi cant immobilization of F. candida at 10 mg L -1 whereas no toxic effect occurred at 40 mg L -1 [40]. This is in line with our ndings.…”

Section: Discussionsupporting

confidence: 92%

Low concentration effects and different outcome in repeated reproduction tests with silver nanoparticles, silver nitrate and Folsomia candida (Collembola)

Filser²

2020

Preprint

Self Cite

Background Toxicity of silver nanoparticles (AgNP) has been studied frequently due to a rise in application in various products. Various studies on AgNP toxicity with terrestrial and aquatic organisms confirmed their negative effects. In our previous experiments, strong variability was observed in the reproduction of Collembola (Folsomia candida) in different repeats. To investigate the effects of silver on the reproduction of Folsomia candida, they were exposed in laboratory controlled conditions to AgNP and silver nitrate (AgNO3) at a concentration of 30 mg/kg dry soil for 28 days and compared to controlled individuals not exposed to silver. The temporal variability of the reproduction using Folsomia candida and its sensitivity to silver was explored by repeating the tests were four times in April, July, October and January through out one year. Results While adult survival was similar in all treatments and seasons, reproduction in the control increased from April to October. Significantly lower reproduction was found in January with only 385-424 juveniles per vessel, compared to 504-633 individuals in other months. Strong toxic effects of both silver treatments were observed in July, April and October. However, AgNP showed no toxic effects on the reproduction of F. candida in January. The relative toxicity of both substances varied between single experiments: AgNP were more toxic than AgNO3 in April and July, and less toxic in October and January. Conclusion These findings indicate that the reproduction of F. candida in the control had a significant effect on the results of the toxicology experiments. Moreover, we demonstrated the reproductive toxicity of AgNP in soil at a much lower concentration than reported thus far. Therefore, to guarantee reliability and reproducibility, we recommend to disregard any test results where the reproduction rate of F. candida in the control is significantly different from the average in the respective laboratory, even if the validity criteria of the test are met.