Release characteristics of selected carbon nanotube polymer composites

Multi-walled carbon nanotubes (MWCNTs) are commonly used in polymer formulations to improve strength, conductivity, and other attributes. A developing concern is the potential for carbon nanotube polymer nanocomposites to release nanoparticles into the environment as the polymer matrix degrades or is mechanically stressed. Here, we review characteristics related to release potential of five sets of polymer systems: epoxy, polyamide, polyurethane, polyethylene, and polycarbonate. Our review includes consideration of general characteristics and use of the polymer (as related to potential MWCNT release) and its MWCNT composites; general potential for nanomaterial release (particularly MWCNTs) due to degradation and mechanical stresses during use; and potential effects of stabilizers and plasticizers on polymer degradation. We examine UV degradation, temperature extremes, acid-base catalysis, and stresses such as sanding. Based on a high-level summary of the characteristics considered, the potential for release of MWCNT with typical, intended consumer use is expected to be low. © 2013 Elsevier Ltd. All rights reserved

The success of the Montreal Protocol in mitigating interactive effects of stratospheric ozone depletion and climate change on the environment

The Montreal Protocol and its Amendments have been highly effective in protecting the stratospheric ozone layer, preventing global increases in solar ultraviolet-B radiation (UV-B; 280-315 nm) at Earth's surface, and reducing global warming. While ongoing and projected changes in UV-B radiation and climate still pose a threat to human health, food security, air and water quality, terrestrial and aquatic ecosystems, and construction materials and fabrics, the Montreal Protocol continues to play a critical role in protecting Earth's inhabitants and ecosystems by addressing many of the United Nations Sustainable Development Goals.Non peer reviewe

United Nations Environment Programme (UNEP), Questions and Answers about the Effects of Ozone Depletion, UV Radiation, and Climate on Humans and the Environment. Supplement of the 2022 Assessment Report of the UNEP Environmental Effects Assessment Panel

This collection of Questions & Answers (Q&As) was prepared by the Environmental Effects Assessment Panel (EEAP) of the Montreal Protocol under the umbrella of the United Nations Environment Programme (UNEP). The document complements EEAP’s Quadrennial Assessment 2022 (https://ozone. unep.org/science/assessment/eeap) and provides interesting and useful information for policymakers, the general public, teachers, and scientists, written in an easy-to-understand language

Environmental effects of stratospheric ozone depletion, UV radiation, and interactions with climate change: UNEP Environmental Effects Assessment Panel, Update 2020

This assessment by the Environmental Effects Assessment Panel (EEAP) of the United Nations Environment Programme (UNEP) provides the latest scientific update since our most recent comprehensive assessment (Photochemical and Photobiological Sciences, 2019, 18, 595–828). The interactive effects between the stratospheric ozone layer, solar ultraviolet (UV) radiation, and climate change are presented within the framework of the Montreal Protocol and the United Nations Sustainable Development Goals. We address how these global environmental changes affect the atmosphere and air quality; human health; terrestrial and aquatic ecosystems; biogeochemical cycles; and materials used in outdoor construction, solar energy technologies, and fabrics. In many cases, there is a growing influence from changes in seasonality and extreme events due to climate change. Additionally, we assess the transmission and environmental effects of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is responsible for the COVID-19 pandemic, in the context of linkages with solar UV radiation and the Montreal Protocol.PWB was supported by the J.H. Mullahy Endowment for Environmental Biology. TMR was partially supported by the University of Helsinki, Faculty of Biological & Environmental Sciences, and by the Academy of Finland (decision #324555). PJN was supported by the Smithsonian Institution. CEW was supported by NSF DEB 1754267, and NSF DEB 1950170. RGZ was supported by the US Environmental Protection Agency—the views expressed in this article are those of the authors and do not necessarily represent the views or policies of the U.S. Environmental Protection Agency. ATB was supported by the Universidad Nacional Autónoma de México and thanks M. en C. Laura Celis for help with literature searches. SH was supported by the Swedish Environmental Protection Agency and Linnaeus University. MAKJ was supported by Science Foundation Ireland (16-IA-4418). JM-A was supported by the Spanish Ministry of Science, Innovation and Universities and European Regional Development Fund (project PGC2018-093824-B-C42). KM was supported by ETH Zurich. LER was supported by the NIHR Manchester Biomedical Research Centre. SAR was supported by the Australian Research Council and the University of Wollongong’s Global Challenges Program. KCR was supported by NSF grants 1754265 and 1761805. Q-WW gratefully acknowledges fnancial support from the CAS Young Talents Program and National Natural Science Foundation of China (41971148). SY was supported by Australian National Health and Medical Research Council CJ Martin Fellowship. We thank Emma Lesley (Global Challenges Program, University of Wollongong, for assistance with Fig. 1)

Environmental Effects of Stratospheric Ozone Depletion, UV Radiation, and interactions with Climate Change: 2022 Assessment Report

The Montreal Protocol on Substances that Deplete the Ozone Layer was established 35 years ago following the 1985 Vienna Convention for protection of the environment and human health against excessive amounts of harmful ultraviolet-B (UV-B, 280-315 nm) radiation reaching the Earth’s surface due to a reduced UV-B-absorbing ozone layer. The Montreal Protocol, ratified globally by all 198 Parties (countries), controls ca 100 ozone-depleting substances (ODS). These substances have been used in many applications, such as in refrigerants, air conditioners, aerosol propellants, fumigants against pests, fire extinguishers, and foam materials. The Montreal Protocol has phased out nearly 99% of ODS, including ODS with high global warming potentials such as chlorofluorocarbons (CFC), thus serving a dual purpose. However, some of the replacements for ODS also have high global warming potentials, for example, the hydrofluorocarbons (HFCs). Several of these replacements have been added to the substances controlled by the Montreal Protocol. The HFCs are now being phased down under the Kigali Amendment. As of December 2022, 145 countries have signed the Kigali Amendment, exemplifying key additional outcomes of the Montreal Protocol, namely, that of also curbing climate warming and stimulating innovations to increase energy efficiency of cooling equipment used industrially as well as domestically. As the concentrations of ODS decline in the upper atmosphere, the stratospheric ozone layer is projected to recover to pre-1980 levels by the middle of the 21st century, assuming full compliance with the control measures of the Montreal Protocol. However, in the coming decades, the ozone layer will be increasingly influenced by emissions of greenhouse gases and ensuing global warming. These trends are highly likely to modify the amount of UV radiation reaching the Earth\u27s surface with implications for the effects on ecosystems and human health. Against this background, four Panels of experts were established in 1988 to support and advise the Parties to the Montreal Protocol with up-to-date information to facilitate decisions for protecting the stratospheric ozone layer. In 1990 the four Panels were consolidated into three, the Scientific Assessment Panel, the Environmental Effects Assessment Panel, and the Technology and Economic Assessment Panel. Every four years, each of the Panels provides their Quadrennial Assessments as well as a Synthesis Report that summarises the key findings of all the Panels. In the in-between years leading up to the quadrennial, the Panels continue to inform the Parties to the Montreal Protocol of new scientific information

From Pollution To Solution: a global assessment of marine litter and plastic pollution

Outcome from working on the United Nations Environment Programme Advisory Group with the aim to address the UN Environment Assembly’s adopted resolution (UN/EA.4/RES.6) on Marine Plastic Litter and Microplastics by recommending indicators to harmonise monitoring and assessment and informing on policies and action environmentally sound technology innovations

Ozone depletion, ultraviolet radiation, climate change and prospects for a sustainable future

Changes in stratospheric ozone and climate over the past 40-plus years have altered the solar ultraviolet (UV) radiation conditions at the Earth's surface. Ozone depletion has also contributed to climate change across the Southern Hemisphere. These changes are interacting in complex ways to affect human health, food and water security, and ecosystem services. Many adverse effects of high UV exposure have been avoided thanks to the Montreal Protocol with its Amendments and Adjustments, which have effectively controlled the production and use of ozone-depleting substances. This international treaty has also played an important role in mitigating climate change. Climate change is modifying UV exposure and affecting how people and ecosystems respond to UV; these effects will become more pronounced in the future. The interactions between stratospheric ozone, climate and UV radiation will therefore shift over time; however, the Montreal Protocol will continue to have far-reaching benefits for human well-being and environmental sustainability.Peer reviewe

United Nations Environment Programme (UNEP), Plastics in the environment in the context of UV radiation, climate change and the Montreal Protocol. 2023 Assessment Update of the UNEP Environmental Effects Assessment Panel

Solar ultraviolet radiation is a contributing factor in the environmental fate of toxic chemicals and other contaminants, with consequences that may be either beneficial or detrimental for the health of humans and the environment. This Assessment Update (2023) by the Environmental Effects Assessment Panel (EEAP) focusses on the role and significance of UV radiation and associated drivers on the breakdown of plastic waste in the environment. Plastic is a ubiquitous pollutant. UV radiation and mechanical stress drive the degradation and fragmentation of larger plastic waste into smaller micro- and nanoplastics. The Assessment Update considers the interactive effects of UV radiation and climate change on plastic durability, weathering, longevity, and ultimately the fate of plastic debris

Microplastics in the marine environment

This review discusses the mechanisms of generation and potential impacts of microplastics in the ocean environment. Weathering degradation of plastics on the beaches results in their surface embrittlement and microcracking, yielding microparticles that are carried into water by wind or wave action. Unlike inorganic fines present in sea water, microplastics concentrate persistent organic pollutants (POPs) by partition. The relevant distribution coefficients for common POPs are several orders of magnitude in favour of the plastic medium. Consequently, the microparticles laden with high levels of POPs can be ingested by marine biota. Bioavailability and the efficiency of transfer of the ingested POPs across trophic levels are not known and the potential damage posed by these to the marine ecosystem has yet to be quantified and modelled. Given the increasing levels of plastic pollution of the oceans it is important to better understand the impact of microplastics in the ocean food web