Environmental exposure of a simulated pond ecosystem to a CuO nanoparticle-based wood stain throughout its life cycle

Abstract

Indoor aquatic mesocosms were used to assess the behavior of fragmented products of a wood stain containing CuO nanoparticles in a simulated pond ecosytem for 1 month. Byproducts of degradation containing Cu are likely to be released during the use and end-of-life of this wood stain. Over two months, a pond ecosystem was mimicked in 60 L tanks and exposed in environmentally relevant conditions to fragmented products of CuO nanoparticle-based wood stain or pristine CuO nanoparticles. Cu (bio)transformation and (bio)distribution within different environmental compartments (e.g. water, sediments, benthic grazers) were carefully analyzed. Because of the presence of the stain matrix, CuO nanoparticles contained in fragmented products were less bio-physical-chemically transformed (dissolution, complexation) with respect to pristine nanoparticles. After 28 days, only 1% of the Cu injected following fragmented product exposure remained in the water column (0.08 µg.L -1 ), against 10% for the pristine CuO nanoparticles (2.67 µg.L -1 ). Among these ~10%, ~51% were dissolved Cu species (1.35 µg.L -1 ). These results are discussed with respect to the ecological compartments in which they accumulated, and to the dose to which aquatic organisms with distinct life traits were exposed.

Monitoring the Environmental Aging of Nanomaterials: An Opportunity for Mesocosm Testing?

“…Mesocosm testing is an increasingly popular alternative to traditional procedures for examining the environmental risks of nanomaterials, because (i) by design, it accounts for system complexity to a level that no other single test does, and (ii) multiple exposure and hazard parameters/end points can be characterized in a single experiment, based on real time monitoring (e.g., multi-parameter probes) and off-line analyses [12,13,14,15,16,17,18,19]. The general strategy behind mesocosm testing is in sharp contrast with detailed parameter/end-point determination; while strict control of every aspect of the procedure is at the core of a traditional standard, mesocosms are expected to evolve freely after their set-up and stabilization period [13] for durations of at least several weeks, and up to a year or longer in some cases [18,20].…”

“…As an example, the distribution of Ce in an aquatic mesocosm, expressed as a percentage of the introduced material, was about 1% in the water column, 99% at the surface of the sediment and less than 0.1% in P. Corneus in the case of a single dosing contamination scenario, whereas for multiple dosing, these proportions were 89%, 11% and <0.1%, respectively [15]. While it is acknowledged that the combination of multiple bio-physicochemical stresses may cause transformations of the nanomaterial during the experiment, mesocosm testing is only rarely designed to specifically cause or address aging [12,22].…”

“…To address more advanced stages of degradation, it is of course possible to use pre-aged materials for the contamination phase of the mesocosm experiment. In previous studies, a methodology has been developed (such as the use of fragmented products) so as to speed up the degradation of long-lived materials, notably by increasing the surface area at the product/environment interface while keeping the material identical to the real product [12,21].…”

The necessity of investigating a freshwater-marine continuum using a mesocosm approach in nanosafety: The case study of TiO2 MNM-based photocatalytic cement

“…Freshwater mesocosms. The mesocosm experiments were already described by Auffan et al (2014), Tella et al (2014), Tella et al (2015), Auffan et al (2018)(figure 1). Tanks (750 x 200…”

“…This species belongs to the Planorbidae, the largest family of aquatic pulmonate gastropods distributed all over the world (Jopp, 2006). Planorbarius corneus play an important role in trophic chains as grazer and as prey (Wojdak and Trexler, 2010) and have already been used as model organisms for exposure and toxicity studies in mesocosms (Tella et al 2014, Auffan 2018.…”