title: The effect of chronic silver nanoparticles on aquatic system in microcosms.
abstract: Silver nanoparticles (AgNPs) inevitably discharge into aquatic environments due to their abundant use in antibacterial products. It was reported that in laboratory conditions, AgNPs display dose-dependent toxicity to aquatic organisms, such as bacteria, algae, macrophytes, snails and fishes. However, AgNPs could behave differently in natural complex environments. In the present study, a series of microcosms were established to investigate the distribution and toxicity of AgNPs at approximately 500 μg L-1in aquatic systems. As a comparison, the distribution and toxicity of the same concentration of AgNO3were also determined. The results showed that the surface layer of sediment was the main sink of Ag element for both AgNPs and AgNO3. Both aquatic plant (Hydrilla verticillata) and animals (Gambusia affinis and Radix spp) significantly accumulated Ag. With short-term treatment, phytoplankton biomass was affected by AgNO3but not by AgNPs. Chlorophyll content of H. verticillata increased with both AgNPs and AgNO3short-term exposure. However, the biomass of phytoplankton, aquatic plant and animals was not significantly different between control and samples treated with AgNPs or AgNO3for 90 d. The communities, diversity and richness of microbes were not significantly affected by AgNPs and AgNO3; in contrast, the nitrification rate and its related microbe (Nitrospira) abundance significantly decreased. AgNPs and AgNO3may affect the nitrogen cycle and affect the environment and, since they might be also transferred to food web, they represent a risk for health.
authors.affiliation: Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, 430074, China; University of Chinese Academy of Sciences, Beijing 100049, China; Aix Marseille Univ CNRS, BIP UMR 7281, IMM, FR 3479, 31 Chemin Joseph Aiguier, 13402 Marseille Cedex 20, France.
authors.forename: Hong Sheng
authors.initials: HS
authors.lastname: Jiang
authors.affiliation: Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, Agricultural College, Hainan University, Haikou, 570228, China. Electronic address: lyyin@163.com.
authors.forename: Liyan
authors.initials: L
authors.lastname: Yin
authors.affiliation: College of Geosciences, China University of Petroleum, Beijing 102249, China.
authors.forename: Na Na
authors.initials: NN
authors.lastname: Ren
authors.affiliation: Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, 430074, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Xian
authors.affiliation: Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, 430074, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Suting
authors.initials: S
authors.lastname: Zhao
authors.affiliation: Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, 430074, China; Hubei Key Laboratory of Wetland Evolution & Ecological Restoration, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, China. Electronic address: liwei@wbgcas.cn.
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.affiliation: Aix Marseille Univ CNRS, BIP UMR 7281, IMM, FR 3479, 31 Chemin Joseph Aiguier, 13402 Marseille Cedex 20, France.
authors.forename: Brigitte
authors.initials: B
authors.lastname: Gontero
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000032:analysis / Q000493:pharmacokinetics / Q000633:toxicity*; D059001:Aquatic Organisms / Q000187:drug effects* / Q000378:metabolism; D044822:Biodiversity; D018533:Biomass; D004781:Environmental Exposure / Q000009:adverse effects* / Q000032:analysis; D004784:Environmental Monitoring; D019015:Geologic Sediments / Q000737:chemistry; D053768:Metal Nanoparticles / Q000032:analysis / Q000633:toxicity*; D058465:Nitrification / Q000187:drug effects; D010839:Phytoplankton / Q000187:drug effects / Q000378:metabolism; D018030:Silver Compounds / Q000032:analysis / Q000493:pharmacokinetics / Q000633:toxicity*; D018675:Toxicity Tests; D062065:Wastewater / Q000737:chemistry*; D014877:Water Pollution, Chemical / Q000009:adverse effects* / Q000032:analysis
chemical_list: D000900:Anti-Bacterial Agents; D018030:Silver Compounds; D062065:Wastewater
keywords: 16S rDNA; AgNPs; Aquatic system; Microbe; Nitrification