This review aims to elucidate the current knowledge and future research needs regarding the hazard potential of nanocellulose to human health. Growing interest from research and industry alike has led to increasing likelihood of human contact to the material via various exposure routes. Although a number of comprehensive reviews on human health hazards of nanocellulose have been conducted, this paper brings new insights as it systematically analyzes and quantitatively assesses the results of in vivo and in vitro tests in terms of investigated endpoints, tested concentration ranges, physicochemical properties, surface modifications and source of the tested nanocellulose, exposure route, and cell lines used. The quality of the studies is further inspected based on various established criteria. Considering the rapid development of nanocellulose-based products and the novelty of the material, human health studies remain scarce. By assessing those that have been conducted, patterns and gaps were identified that will be helpful to guide future research. The results show that there are still significant uncertainties remaining, particularly regarding in vivo testing, with pulmonary exposure showing some cause for concern. Although a substantial number of in vitro studies have been undertaken, results are often conflicting. The detected effects could not be directly attributed to size of nanoparticles, cell lines, surface modifications or tested concentrations. This may also be linked to the varying quality of the studies. This review ends by identifying key gaps to help pave the way for future research and ensure the safe development and use of nanocellulose.

The many appealing properties of nanocellulose have led to increasing interest in the material from research and industry over the past years, with the material showing potential for both industrial and consumer goods. This will unavoidably lead to increasing release of nanocellulose into the environment. Although nanocellulose is largely regarded as non-toxic, knowledge gaps surrounding its impacts on the environment and human health still exist and data remains scarce. This study aimed to quantitatively assess the environmental risk of nanocellulose by characterizing both environmental exposure and hazard. Firstly, a probabilistic species sensitivity distribution (PSSD) was developed to assess the hazard by calculating the predicted no effect concentration (PNEC) of the surface water compartment, resulting in a PNEC of 7.8 mg l⁻¹ (mean value of the distribution). Secondly, the dynamic probabilistic material flow assessment (DPMFA) method was employed to assess the exposure by quantifying the predicted environmental concentration (PEC), using the European Union as a system boundary, and 2000 to 2025 as timeframe. This resulted in a PEC in surface water of 0.23 μg l⁻¹ in 2015 and 2.37 μg l⁻¹ in 2025 (mean values). The PEC and PNEC distributions allowed for the calculation of the risk characterization ratio (RCR). Results show an RCR of 6.9 × 10⁻⁵ in 2015, and 7.1 × 10⁻⁴ in 2025, implying that under the chosen assumptions there is no present or future environmental risk surrounding nanocellulose within the surface water compartment, even assuming a compound annual growth rate of 19% for nanocellulose production in upcoming years.

Microplastics are ubiquitous in ecosystems and a lot of research is being performed to understand their environmental fate and effects on organisms. However, the release and impact of MP has so far not been considered in LCA studies. This is due to missing information on the inventory side about microplastic releases and missing Characterization Factors to quantify the effects of MP. The goal of this study was to elucidate the relevance of MP release into freshwaters from an LCA perspective, by using worst-case assumptions. In accordance with the USEtox framework, an interim and simplified Characterization Factor for the impact category of freshwater ecotoxicity was calculated to be 3231 PAF·m³·d·kg⁻¹. Applying this Characterization Factor, two LCA case studies were conducted, one on a polyester T-Shirt and one with a shower gel containing microplastics. The results show a small contribution of microplastics to the freshwater ecotoxicity for a scenario with state-of-the-art wastewater treatment. Different scenarios varying in microplastic release and removal during wastewater treatment and a sensitivity analysis of the Characterization Factor allowed identifying the potential range of the microplastic contribution to the overall ecotoxicity. In conclusion, the inclusion of microplastic release into LCA only marginally influences the overall environmental effects of the two products in the LCA case studies.

Community-based natural resource management (CBNRM) is a widely used approach aimed at involving those utilizing resources in their management. In Madagascar, where forest decentralization has been implemented since the 1990s to spur local resource users’ involvement in management processes, impacts remain unclear. This study aimed to investigate farmers’ perceptions and practices regarding forest use under various forest governance systems, using a participatory gaming approach implemented in the Zahamena region of Madagascar. We report on (i) the conceptual models of the Zahamena socio-ecological system; (ii) the actual research tool in the form of a tabletop role-playing game; and (iii) main outcomes of the gaming workshops and accompanying research. The results allow the linking of game reality with real-world perceptions based on game debriefing discussions and game workshop follow-up surveys, as well as interviews and focus group research with other natural resource users from the study area. Results show that the Zahamena protected area plays the role of buffer zone by slowing down deforestation and degradation. However, this fragile barrier and CBNRM are not long-term solutions in the face of occurring changes. Rather, the solution lies in one of the main causes of the problem: agriculture. Further use of tools such as participatory gaming is recommended to enhance knowledge exchange and the development of common visions for the future of natural resource management to foster resilience of forest governance.