This study aimed to enhance our insight on the potential toxicological effects of silver nanoparticles (AgNPs) into the aquatic environment. To investigate the chronic toxicity of nanoparticles, freshwater micro-crustacean Daphnia lumholtzi was exposed to different concentrations of , µg/l AgNPs, and control, for 21 days. | Chronic effects of silver nanoparticles on micro crustacean Daphnia lumholtzi VNU Journal of Science Natural Sciences and Technology Vol. 36 No. 2 2020 54-61 Original Article Chronic Effects of Silver Nanoparticles on Micro-Crustacean Daphnia lumholtzi Tran Thanh Thai1 Pham Thanh Luu1 2 Ngo Xuan Quang1 2 Dao Thanh Son3 1 Institute of Tropical Biology Vietnam Academy of Science and Technology 85 Tran Quoc Toan District 3 Ho Chi Minh Vietnam 2 Graduate University of Science and Technology Vietnam Academy of Science and Technology 18 Hoang Quoc Viet Cau Giay Hanoi Vietnam 3 Hochiminh City University of Technology Vietnam National University-Hochiminh City 268 Ly Thuong Kiet District 10 Ho Chi Minh Vietnam Received 19 October 2019 Revised 31 January 2020 Accepted 27 February 2020 Abstract This study aimed to enhance our insight on the potential toxicological effects of silver nanoparticles AgNPs into the aquatic environment. To investigate the chronic toxicity of nanoparticles freshwater micro-crustacean Daphnia lumholtzi was exposed to different concentrations of µg l AgNPs and control for 21 days. Toxicological endpoints at different growing stages such as the maturation and reproduction were recorded. The reproduction rate of D. lumholtzi exposed to both AgNPs concentrations and µg l was significantly lower than that of control. In turn the maturation exposed to both AgNPs concentrations was not significantly different from the control treatment. This result indicates that AgNPs with a concentration lower than µg l did not have an adverse effect on the maturation of D. lumholtzi but AgNPs with a concentration higher than caused a toxic effect on the reproduction rate of D. lumholtzi during 21 days of the exposure period. In conclusion the present results showed that AgNPs have toxic effects on D. lumholtzi and it has the potential to use as good freshwater aquatic zooplankton for assessment on the toxicity of nanomaterials in tropics. The .
