Continuing benefits of the Montreal Protocol and protection of the stratospheric ozone layer for human health and the environment.

The protection of Earth's stratospheric ozone (O3) is an ongoing process under the auspices of the universally ratified Montreal Protocol and its Amendments and adjustments. A critical part of this process is the assessment of the environmental issues related to changes in O3. The United Nations Environment Programme's Environmental Effects Assessment Panel provides annual scientific evaluations of some of the key issues arising in the recent collective knowledge base. This current update includes a comprehensive assessment of the incidence rates of skin cancer, cataract and other skin and eye diseases observed worldwide; the effects of UV radiation on tropospheric oxidants, and air and water quality; trends in breakdown products of fluorinated chemicals and recent information of their toxicity; and recent technological innovations of building materials for greater resistance to UV radiation. These issues span a wide range of topics, including both harmful and beneficial effects of exposure to UV radiation, and complex interactions with climate change. While the Montreal Protocol has succeeded in preventing large reductions in stratospheric O3, future changes may occur due to a number of natural and anthropogenic factors. Thus, frequent assessments of potential environmental impacts are essential to ensure that policies remain based on the best available scientific knowledge.

Changes in tropospheric air quality related to the protection of stratospheric ozone in a changing climate.

Ultraviolet (UV) radiation drives the net production of tropospheric ozone (O3) and a large fraction of particulate matter (PM) including sulfate, nitrate, and secondary organic aerosols. Ground-level O3 and PM are detrimental to human health, leading to several million premature deaths per year globally, and have adverse effects on plants and the yields of crops. The Montreal Protocol has prevented large increases in UV radiation that would have had major impacts on air quality. Future scenarios in which stratospheric O3 returns to 1980 values or even exceeds them (the so-called super-recovery) will tend to ameliorate urban ground-level O3 slightly but worsen it in rural areas. Furthermore, recovery of stratospheric O3 is expected to increase the amount of O3 transported into the troposphere by meteorological processes that are sensitive to climate change. UV radiation also generates hydroxyl radicals (OH) that control the amounts of many environmentally important chemicals in the atmosphere including some greenhouse gases, e.g., methane (CH4), and some short-lived ozone-depleting substances (ODSs). Recent modeling studies have shown that the increases in UV radiation associated with the depletion of stratospheric ozone over 1980-2020 have contributed a small increase (~ 3%) to the globally averaged concentrations of OH. Replacements for ODSs include chemicals that react with OH radicals, hence preventing the transport of these chemicals to the stratosphere. Some of these chemicals, e.g., hydrofluorocarbons that are currently being phased out, and hydrofluoroolefins now used increasingly, decompose into products whose fate in the environment warrants further investigation. One such product, trifluoroacetic acid (TFA), has no obvious pathway of degradation and might accumulate in some water bodies, but is unlikely to cause adverse effects out to 2100.

Linkages between COVID-19, solar UV radiation, and the Montreal Protocol.

There are several connections between coronavirus disease 2019 (COVID-19), solar UV radiation, and the Montreal Protocol. Exposure to ambient solar UV radiation inactivates SARS-CoV-2, the virus responsible for COVID-19. An action spectrum describing the wavelength dependence of the inactivation of SARS-CoV-2 by UV and visible radiation has recently been published. In contrast to action spectra that have been assumed in the past for estimating the effect of UV radiation on SARS-CoV-2, the new action spectrum has a large sensitivity in the UV-A (315-400 nm) range. If this "UV-A tail" is correct, solar UV radiation could be much more efficient in inactivating the virus responsible for COVID-19 than previously thought. Furthermore, the sensitivity of inactivation rates to the total column ozone would be reduced because ozone absorbs only a small amount of UV-A radiation. Using solar simulators, the times for inactivating SARS-CoV-2 have been determined by several groups; however, many measurements are affected by poorly defined experimental setups. The most reliable data suggest that 90% of viral particles embedded in saliva are inactivated within ~ 7 min by solar radiation for a solar zenith angle (SZA) of 16.5° and within ~ 13 min for a SZA of 63.4°. Slightly longer inactivation times were found for aerosolised virus particles. These times can become considerably longer during cloudy conditions or if virus particles are shielded from solar radiation. Many publications have provided evidence of an inverse relationship between ambient solar UV radiation and the incidence or severity of COVID-19, but the reasons for these negative correlations have not been unambiguously identified and could also be explained by confounders, such as ambient temperature, humidity, visible radiation, daylength, temporal changes in risk and disease management, and the proximity of people to other people. Meta-analyses of observational studies indicate inverse associations between serum 25-hydroxy vitamin D (25(OH)D) concentration and the risk of SARS-CoV-2 positivity or severity of COVID-19, although the quality of these studies is largely low. Mendelian randomisation studies have not found statistically significant evidence of a causal effect of 25(OH)D concentration on COVID-19 susceptibility or severity, but a potential link between vitamin D status and disease severity cannot be excluded as some randomised trials suggest that vitamin D supplementation is beneficial for people admitted to a hospital. Several studies indicate significant positive associations between air pollution and COVID-19 incidence and fatality rates. Conversely, well-established cohort studies indicate no association between long-term exposure to air pollution and infection with SARS-CoV-2. By limiting increases in UV radiation, the Montreal Protocol has also suppressed the inactivation rates of pathogens exposed to UV radiation. However, there is insufficient evidence to conclude that the expected larger inactivation rates without the Montreal Protocol would have had tangible consequences on the progress of the COVID-19 pandemic.

Environmental effects of stratospheric ozone depletion, UV radiation, and interactions with climate change: UNEP Environmental Effects Assessment Panel, Update 2021.

The Environmental Effects Assessment Panel of the Montreal Protocol under the United Nations Environment Programme evaluates effects on the environment and human health that arise from changes in the stratospheric ozone layer and concomitant variations in ultraviolet (UV) radiation at the Earth's surface. The current update is based on scientific advances that have accumulated since our last assessment (Photochem and Photobiol Sci 20(1):1-67, 2021). We also discuss how climate change affects stratospheric ozone depletion and ultraviolet radiation, and how stratospheric ozone depletion affects climate change. The resulting interlinking effects of stratospheric ozone depletion, UV radiation, and climate change are assessed in terms of air quality, carbon sinks, ecosystems, human health, and natural and synthetic materials. We further highlight potential impacts on the biosphere from extreme climate events that are occurring with increasing frequency as a consequence of climate change. These and other interactive effects are examined with respect to the benefits that the Montreal Protocol and its Amendments are providing to life on Earth by controlling the production of various substances that contribute to both stratospheric ozone depletion and climate change.

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.

Genetics of facial telangiectasia in the Rotterdam Study: a genome-wide association study and candidate gene approach.

BACKGROUND: The severity of facial telangiectasia or red veins is associated with many lifestyle factors. However, the genetic predisposition remains unclear. OBJECTIVES: We performed a genome-wide association study (GWAS) on facial telangiectasia in the Rotterdam Study (RS) and tested for replication in two independent cohorts. Additionally, a candidate gene approach with known pigmentation genes was performed. METHODS: Facial telangiectasia were extracted from standardized facial photographs (collected from 2010-2013) of 2842 northwestern European participants (median age 66.9, 56.8% female) from the RS. Our GWAS top hits (P-value <10-6 ) were tested for replication in 460 elderly women of the SALIA cohort and in 576 additional men and women of the RS. Associations of top single nucleotide polymorphisms (SNPs) with expression quantitative trait loci (eQTL) in various tissues were reviewed (GTEx database) alongside phenotype associations in the UK biobank database. SNP-based associations between known pigmentation genes and facial telangiectasia were tested. Conditional analysis on skin colour was additionally performed. RESULTS: Our most significant GWAS signal was rs4417318 (P-value 5.38*10-7 ), an intergenic SNP on chromosome 12 mapping to the SLC16A7 gene. Other suggestive SNPs tagged genes ZNF211, ZSCAN4, ICOS and KCNN3; SNP eQTLs and phenotype associations tagged links to the vascular system. However, the top signals did not pass significance in the two replication cohorts. The pigmentation genes KIAA0930, SLCA45A2 and MC1R, were significantly associated with telangiectasia in a candidate gene approach but not independently of skin colour. CONCLUSION: In this GWAS on telangiectasia in a northwestern European population, no genome-wide significant SNPs were found, although suggestive signals indicate genes involved in the vascular system might be involved in telangiectasia. Significantly associated pigmentation genes underline the link between skin colour and telangiectasia.

Environmental effects of stratospheric ozone depletion, UV radiation and interactions with climate change: UNEP Environmental Effects Assessment Panel, update 2019.

This assessment, by the United Nations Environment Programme (UNEP) Environmental Effects Assessment Panel (EEAP), one of three Panels informing the Parties to the Montreal Protocol, provides an update, since our previous extensive assessment (Photochem. Photobiol. Sci., 2019, 18, 595-828), of recent findings of current and projected interactive environmental effects of ultraviolet (UV) radiation, stratospheric ozone, and climate change. These effects include those on human health, air quality, terrestrial and aquatic ecosystems, biogeochemical cycles, and materials used in construction and other services. The present update evaluates further evidence of the consequences of human activity on climate change that are altering the exposure of organisms and ecosystems to UV radiation. This in turn reveals the interactive effects of many climate change factors with UV radiation that have implications for the atmosphere, feedbacks, contaminant fate and transport, organismal responses, and many outdoor materials including plastics, wood, and fabrics. The universal ratification of the Montreal Protocol, signed by 197 countries, has led to the regulation and phase-out of chemicals that deplete the stratospheric ozone layer. Although this treaty has had unprecedented success in protecting the ozone layer, and hence all life on Earth from damaging UV radiation, it is also making a substantial contribution to reducing climate warming because many of the chemicals under this treaty are greenhouse gases.

Epidemiology and determinants of facial telangiectasia: a cross-sectional study.

BACKGROUND: Telangiectasia or red veins are one of the prominent features of facial skin ageing. To date, there are few studies investigating the determinants of telangiectasia. OBJECTIVES: We investigated lifestyle and physiological factors associated with facial telangiectasia in a large prospective Dutch cohort study. METHODS: Telangiectasia was quantified digitally from standardized facial photographs of 2842 North European participants (56.8% female, median age 66.9) from the Rotterdam Study, collected in 2010-2013. Effect estimates from multivariable linear regressions are presented as the percentage difference in the mean value of telangiectasia area per unit increase of a determinant (%Δ) with corresponding 95% CI. RESULTS: Significant determinants were older age [1.7%Δ per year (95% CI 1.4, 2.0)], female sex [18.3%Δ (95% CI 13.2, 23.6)], smoking [current versus never 38.4%Δ (95% CI 30.3, 47.0); former versus never 11.6%Δ (95% CI 6.6, 16.9)], a high susceptibility to sunburn [10.2%Δ (95% CI 5.4, 15.3)] and light skin colour [pale versus white-to-olive 31.4%Δ (95% CI 19.7, 44.1]; white vs. white-to-olive 9.2%Δ (95% CI 2.8, 16.0)]. CONCLUSIONS: In this large cohort study, we confirmed known and described new determinants of facial telangiectasia.

[Air pollution (particulate matter and nitrogen dioxide) and skin aging]. / Luftverschmutzung (Feinstaub, Stickstoffdioxid) und Hautalterung.

It has recently been discovered that air pollution can contribute to skin aging. This conclusion is based on both epidemiological and mechanistic evidence. Specifically, exposure to ambient relevant particulate matter and to nitrogen dioxide (NO2) is associated with an increased risk to develop facial pigment spots. In addition, genetic studies indicate the involvement of gene-environment interactions because women carrying certain genetic variants of the aryl hydrocarbon receptor (AHR) signaling pathway have a higher risk to develop facial pigment spots in response to exposure to particulate matter (PM2.5). Mechanistic studies prove a cause/effect relationship because topical exposure of human skin ex vivo or in vivo to non-toxic concentrations of a standardized diesel exhaust mixture increased skin pigmentation by inducing melanin de novo synthesis via an oxidative stress response. In line with this, cosmetic anti-pollution products containing anti-oxidants, but also AHR antagonists are effective in reducing or preventing this increase in skin pigmentation. Ultraviolet (UV) radiation is another important environmental factor which can cause skin aging and pigment spot formation. In a real exposure situation, human skin is exposed to both environmental factors simultaneously. Corresponding epidemiological studies show that particulate matter present in the troposphere and solar UV radiation interact with each other. These results emphasize that environmentally induced skin aging results from a highly complex process.

[Environmentally induced (extrinsic) skin aging]. / Umweltinduzierte (extrinsische) Hautalterung.

Chronic exposure to ultraviolet light, particularly as a component of natural sunlight, is a major cause of environmentally induced aging of the skin. In addition, other environmental factors for premature skin aging include longer wavelength radiation in the visible light region and in particular in the shortwave infrared radiation region. Furthermore, particulate and gaseous components of air pollution significantly contribute to the aging process.

Asthma and the menopause: a systematic review and meta-analysis.

OBJECTIVE: To review the available literature to determine whether the menopausal transition is associated with asthma incidence. METHODS: We performed a systematic review and meta-analysis of cohort and cross-sectional studies providing a definition/assessment of menopausal status, incidence or prevalence of a defined diagnosis of asthma, and providing a measure of the association or of menopausal state and asthma or enough data for a calculation of this association. Where possible these meta-analytic estimates were also stratified by intake of menopausal hormone therapy (MHT). RESULTS: Of 76 potentially relevant articles, 8 studies met the inclusion criteria and were included in the review, and 6 in the meta-analysis. There was heterogeneity across studies: four studies reported slightly increased prevalence rates of asthma in post-menopause, one large cohort yielded a lower asthma incidence and one cross-sectional study a lower prevalence in post-menopause. Overall, the meta-analysis showed no significant association between menopause and asthma rates. When stratifying by use of MHT, the association between menopause and asthma rates was increased in women reporting use of MHT (RR 1.32, 95%CI 1.01-1.74), but not in women not using MHT. CONCLUSION: We found no significant association of menopause with asthma prevalence or incidence except for women reporting use of MHT. However, these findings result from a small number of studies, including only 1 large cohort with incidence rates for pre- as well as post-menopause. Further studies are needed addressing more closely subgroup analyses and a possible modification of the association of menopause and asthma by MHT.