Pollen Allergy in a Changing Planetary Environment

Green spaces, blue spaces and human health: an updated umbrella review of epidemiological meta-analyses

Introduction

Green spaces have been recognized for their ecological services, including air purification and biodiversity protection, which contribute to the enhancement of life quality and well-being. However, despite the surge in research evaluating the impact of blue-green spaces on health outcomes, we still lack a definitive understanding of how green and blue spaces affect human health outcomes. To assess the impact of blue-green spaces on human health outcomes, we systematically summarized and evaluated the relationship between green and blue spaces and human health through an umbrella review of epidemiological meta-analyses up to the year 2024.

Methods

The study follows the PRISMA guidelines and includes meta analyses from PubMed, Embase, and Cochrane databases, focusing on evidence and methodological improvements. Inclusion criteria encompass studies on human populations, exposure to green and blue spaces, and health outcomes such as mortality, disease risk, and physiological indicators. Data extraction and quality assessment of evidence and methods are conducted using the GRADE system and AMSTAR 2 tool.

Results

We find that green space exposure is associated with reduced all-cause mortality, mortality from cardiovascular diseases, incidence of diabetes and metabolic syndrome, low birth weight, and mental health improvements. Blue spaces also show positive associations with beneficial health outcomes, including reduced obesity rates and improved psychological well-being. However, the evidence regarding green space exposure and specific health outcomes such as cancer, asthma, and allergic rhinitis remains heterogeneous and unclear.

Discussion

Green and blue spaces clearly have some impact on health. For some outcomes, the effects are robust. This article emphasizes the importance of improving residents' health through urban planning in public health strategies.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier [CRD42024533346].

Demographics and clinical features of pediatric patients with allergic rhinitis: a single-center study from Western Turkey

BACKGROUND

Allergic rhinitis (AR) is a disease that has significant effects on the quality of life of people and exhibits different phenotypic features with different clinical findings. By analyzing the data of pediatric patients, we aimed to reveal the relationship between demographic and laboratory data and clinical features and to gain awareness about allergic rhinitis phenotypes in children.

METHODS

Demographic data, clinical complaints, physical examination findings, and atopy biomarkers are retrospectively analyzed to assess the impact of aeroallergens on the disease phenotype.

RESULTS

In a study of 301 AR patients (median age 11 years; 66.1% male), sneezing (79.1%) was the most common complaint, and pallor of the nasal mucosa was the primary examination finding (83.1%). Persistent symptoms were reported by 62.1%, and 60.5% were polysensitized. Notably, 42.5% had asthma, often associated with concurrent sensitization to mold or animal dander (p ≤ 0.05). Pollen was the most prevalent allergen (65.8%), with significant increases in sensitization to pollen (p < 0.001) and animal dander (p = 0.003) with age. Patients with pollen sensitization reported more sneezing (p = 0.026) and persistent symptoms (p ≤ 0.05). Nasal congestion was predominantly seen in house dust mite-sensitized patients (78.4% with concha hypertrophy, p < 0.001). Overall, it was found that 59.7% of monosensitized patients and 63.7% of polysensitized patients reported persistent complaints.

CONCLUSION

This study, conducted in Western Turkey with 301 allergic rhinitis patients, revealed a high prevalence of polysensitization, particularly to pollen and animal dander. Polysensitized patients were older, exhibited higher IgE levels, and more frequently reported sneezing and rhinorrhea. Furthermore, polysensitization was linked to more persistent and severe symptoms, emphasizing the need for personalized treatment strategies for these patients. Our findings highlight the importance of developing individualized and region-specific approaches to enhance the effectiveness of allergic rhinitis management.

Confronting allergies: strategies for combating pollution and safeguarding our health

Increasing evidence demonstrates a robust link between environmental pollutants and allergic reactions, with air and indoor pollution exacerbating respiratory allergies and climate change intensifying seasonal allergies. Comprehensive action, including government regulations, public awareness, and individual efforts, is essential to mitigate pollution's impact on allergies and safeguard public health and ecological balance. Recent findings indicate a strong correlation between environmental pollutants and allergic reactions, with air pollution from vehicular emissions and industrial activities exacerbating respiratory allergies like asthma and allergic rhinitis. Additionally, indoor pollutants such as mold and volatile organic compounds are significant triggers of allergic responses, especially among vulnerable populations. Furthermore, climate change, driven by pollution, is intensifying seasonal allergies due to altered weather patterns and increased pollen production. This review emphasizes the critical importance of addressing pollution and allergies, highlighting the growing concerns in contemporary society. This review highlights the urgent need to address pollution and allergies, emphasizing their increasing significance in modern society and outlining effective allergy management strategies.

Inverse Trend Between Tree Pollen and Fungal Concentrations With Allergic Sensitization Rates in Seoul for 25 Years

A growing number of individuals are developing allergic diseases due to pollen exposure. Seasonal variations and increased pollen concentrations have occurred with the increased rates of allergic sensitization among both children and adults. Temperature significantly influences pollination, particularly in spring- and early summer-flowering plants, with weather conditions affecting pollen allergen levels. Human activities, including agriculture and deforestation, increase carbon emissions, leading to higher atmospheric CO₂ levels that may enhance allergenic plant productivity. Climate change affects the range of allergenic plant species and length of pollen season. Studies indicate that higher CO₂ and temperature levels are linked to increased pollen concentrations and allergenicity, whereas atmospheric fungal concentrations have declined annually over the past 25 years. Despite more intense precipitation in summer and autumn, the number of rainy days has decreased across all seasons. This concentration of rainfall over shorter periods likely prolongs the dry season and shortens the period of fungal sporulation. Future climate changes, including atmospheric dryness, drought, and desertification could further decrease allergenic fungal sporulation. It remains unclear whether the inverse relationship between pollen and fungal concentrations and distributions directly results from climate change. It is crucial to evaluate the patterns of aeroallergens and their associated health risks.

Allergenic Potential of Common Hops (Humulus lupulus L.) in the Context of Cross-Reactions with Pollen Allergens

BACKGROUND

Common hops (Humulus lupulus L.) play a key role in brewing, providing the bitterness, flavor, and aroma of beer, and are widely used in supplements for their antibacterial, anti-inflammatory, and antioxidant properties. However, despite their broad applications, the allergenic potential of common hops remains underexplored, particularly when compared to the closely related Humulus japonicus. This preliminary study aimed to investigate the allergenic potential of common hops and their potential cross-reactivity with common pollen allergens.

METHODS

The immunoreactivity of hop stalks, leaves, and cones was assessed using antibodies against major allergens from birch (Bet v1a), mugwort (Art v1), and timothy grass (Phl p5b), as well as three sera from pollen-allergic patients. Slot Blot analysis was performed using phosphate-buffered saline extracts from the stalks, leaves, and cones of three hop cultivars, while Western Blotting followed SDS-PAGE protein separation.

RESULTS

The results revealed significant immunoreactivity in native hop proteins, with diminished reactivity observed in denatured proteins. Cross-reactivity between hop proteins and major pollen allergens was confirmed, indicating that hop proteins may contribute to allergic sensitization in pollen-sensitive individuals.

CONCLUSIONS

These findings underscore the potential allergenic risks associated with the consumption or exposure to hop-containing products.

Tracking the Spread of Pollen on Social Media Using Pollen-Related Messages From Twitter: Retrospective Analysis

BACKGROUND

Allergy disorders caused by biological particles, such as the proteins in some airborne pollen grains, are currently considered one of the most common chronic diseases, and European Academy of Allergy and Clinical Immunology forecasts indicate that within 15 years 50% of Europeans will have some kind of allergy as a consequence of urbanization, industrialization, pollution, and climate change.

OBJECTIVE

The aim of this study was to monitor and analyze the dissemination of information about pollen symptoms from December 2006 to January 2022. By conducting a comprehensive evaluation of public comments and trends on Twitter, the research sought to provide valuable insights into the impact of pollen on sensitive individuals, ultimately enhancing our understanding of how pollen-related information spreads and its implications for public health awareness.

METHODS

Using a blend of large language models, dimensionality reduction, unsupervised clustering, and term frequency-inverse document frequency, alongside visual representations such as word clouds and semantic interaction graphs, our study analyzed Twitter data to uncover insights on respiratory allergies. This concise methodology enabled the extraction of significant themes and patterns, offering a deep dive into public knowledge and discussions surrounding respiratory allergies on Twitter.

RESULTS

The months between March and August had the highest volume of messages. The percentage of patient tweets appeared to increase notably during the later years, and there was also a potential increase in the prevalence of symptoms, mainly in the morning hours, indicating a potential rise in pollen allergies and related discussions on social media. While pollen allergy is a global issue, specific sociocultural, political, and economic contexts mean that patients experience symptomatology at a localized level, needing appropriate localized responses.

CONCLUSIONS

The interpretation of tweet information represents a valuable tool to take preventive measures to mitigate the impact of pollen allergy on sensitive patients to achieve equity in living conditions and enhance access to health information and services.

Allergen Sensitization and Its Association With Allergic Diseases in the Korean Population: Results From the 2019 Korea National Health and Nutrition Examination Survey

PURPOSE

Allergen exposure is the most potent factor in allergen sensitization, which affects the exacerbation and severity of allergic diseases. Due to industrialization and climate change, the pattern of allergen sensitization has changed over time, and the incidence of allergic diseases has also increased. This study investigated the status of allergen sensitization in the Korean population and its effects on allergic diseases.

METHODS

A total of 2,386 participants aged ≥ 10 years, who underwent 7 specific immunoglobulin E tests for aeroallergens (Dermatophagoides farinae [Der f], dog dander, cat epithelium, birch, oak, Japanese hop, and ragweed), were selected among the participants of the 2019 Korean National Health and Nutrition Examination Survey. We compared the demographic characteristics, combined allergic diseases, and sinusitis symptoms between the atopic and non-atopic groups.

RESULTS

The prevalence of allergen sensitization in the general Korean population was 45%, and Der f was the most frequent cause of sensitization (39.9%). The prevalence of sensitization to indoor allergens was highest among teenagers and those belonging to the 20- to 29-year age group (P < 0.001). In contrast, there was a high prevalence of sensitization to outdoor allergens among individuals belonging to the age group of 60-69 years. The prevalence of atopic dermatitis (odds ratio [OR], 2.559; 95% confidence interval [CI], 1.689-3.878), allergic rhinitis (OR, 3.075; 95% CI, 2.426-3.897), and otitis media (OR, 1.481; 95% CI, 1.092-2.007) significantly increased by allergen sensitization. Patients with allergen sensitization were more likely to experience the symptoms of rhinitis and sinusitis.

CONCLUSIONS

The study findings confirmed that allergen sensitization occurs in approximately half of the general Korean population and affects the prevalence and symptoms of allergic diseases. This suggests that active allergy tests and diagnosis of allergic diseases are necessary in Koreans.

Action-plan and as-needed therapy in allergic rhinitis

Action-plan is a written set of instructions that helps patient manage their symptoms and respond to worsening of their condition. The action-plan usually includes information on how to recognize, treat, and prevent worsening of symptoms. The plan also helps patient understand when to use their medications, how much to use, and how often to use them as-needed. An action-plan should be developed through a discussion between the patient and the physician, reflecting the patient's severity, preferences, and values and should be regularly updated to reflect changes in the person's condition. In asthma, action-plans and as-needed therapy are already well utilized. Unlike asthma, the importance of an action-plan has been overlooked in allergic rhinitis (AR), but its importance has recently been recognized. AR is a chronic condition that affects people differently, and can cause a range of symptoms, including nasal congestion, runny nose, sneezing, itching, and watery eyes. Therefore, an action-plan and as-needed therapy can help patients manage these symptoms more effectively, reducing the impact on their daily activities and quality of life. Furthermore, it can be tailored to meet the personal needs of each patient, based on the severity of their symptoms, their triggers, and their overall health. Because action-plan can help patients adhere to their treatment regimen by providing clear instructions on when and how to take medication, it can help patients stay on track with their treatment, reducing the likelihood of missed doses and treatment failures. Overall, an action-plan and as-needed therapy are important components of a comprehensive treatment plan for patients with AR. They can help to improve symptom control, prevent complications, and promote adherence to treatment, leading to better outcomes and a higher quality of life.

Projections of the start of the airborne pollen season in Barcelona (NE Iberian Peninsula) over the 21st century

The effects of global warming are numerous and recent studies reveal that they can affect the timing of pollination. Temperature is the meteorological variable that presents a clearer relationship with the start of the pollination season of most of the observed airborne pollen taxa. In Catalonia, in the last fifty years, the average annual air temperature has increased by +0.23 °C/decade, and the local warming has been slightly higher than the one on a global scale. Projections point to an increase in temperature in the coming decades, which would be more marked towards the middle of the century. To analyse the effect of the increase in temperature due to global warming on the starting date of pollen season in Barcelona, a forecasting model has been applied to a set of projected future temperatures estimated by the European RESCCUE project. This model, largely used in the literature, is based on determining the thermal needs of the plant for the pollen season to begin. The model calibration to obtain the initial parameters has been made by using 20 years of pollen data (2000-2019), and the model effectiveness has subsequently been tested through an internal evaluation over the period of the calibration and an external evaluation on 4 years not included in the calibration (2020-2023). The mean bias error in the internal calibration ranged between -0.4 and - 0.6 days, and between +0.5 and - 8.3 in the external one, depending on the taxon. The results of the application of the model to the temperature projections over the 21st century point to a progressive advancement in the pollination dates of several pollen types abundant in the city, allergenic most of them. These advances ranged, at the end of the century, between 15 and 27 days, depending on the climate model, for the scenario of the highest concentrations (RCP8.5) and between 7 and 12 days for the emissions stabilization scenario (RCP4.5).

Air pollutants contribute to epithelial barrier dysfunction and allergic diseases

Air pollution is a global problem associated with various health conditions, causing elevated rates of morbidity and mortality. Major sources of air pollutants include industrial emissions, traffic-related pollutants, and household biomass combustion, in addition to indoor pollutants from chemicals and tobacco. Various types of air pollutants originate from both human activities and natural sources. These include particulate matter, pollen, greenhouse gases, and other harmful gases. Air pollution is linked to allergic diseases, including atopic dermatitis, allergic rhinitis, allergic conjunctivitis, food allergy, and bronchial asthma. These pollutants lead to epithelial barrier dysfunction, dysbiosis, and immune dysregulation. In addition, climate change and global warming may contribute to the exacerbation and the development of allergic diseases related to air pollutants. Epigenetic changes associated with air pollutants have also been connected to the onset of allergic diseases. Furthermore, these changes can be passed down through subsequent generations, causing a higher prevalence of allergic diseases in offspring. Modulation of the aryl hydrocarbon receptor could be a valuable strategy for alleviating air pollutant-induced epidermal barrier dysfunction and atopic dermatitis. A more effective approach to preventing allergic diseases triggered by air pollutants is to reduce exposure to them. Implementing public policies aimed at safeguarding individuals from air pollutant exposure may prove to be the most efficient solution. A pressing need exists for global policy initiatives that prioritize efforts to reduce the production of air pollutants.

Prediction Model for Annual Variation in Total Pollen by Allergenic Trees in Korean Cities

PURPOSE

Pollen forecasting systems can provide information for coping with respiratory allergies. They estimate daily pollen production, dispersal, deposition, and removal based on daily weather conditions to predict daily pollen concentrations and provide allergy warnings. As of 2023, the Korea Meteorological Administration (KMA) provides 2-day forecast of allergenic pollens. However, unlike these models, long-term analysis of annual observations of tree pollen reveal annual variations. Therefore, in this study, we aimed to develop annual prediction models for allergenic tree pollens based on long-term multi-site pollen and meteorological data.

METHODS

Daily pollen concentrations were observed using Hirst-type volumetric spore traps at nine sites in Korea from 1998 to 2021, and daily weather data from the closest KMA stations were utilized. Models were developed to predict the seasonal pollen integral of seven tree species based on monthly mean temperature, wind speed, and total precipitation using three variable selection methods: 1) the t-test based key variable screening followed by linear regression with stepwise procedure (TM), 2) direct linear regression with stepwise procedure from the full variable model (FM), and 3) LASSO regression from the full variable model (LM).

RESULTS

Data obtained during 1998-2017 and 2018=2021 were utilized for model development and validation, respectively. The root mean squared error, mean absolute error, mean error, and coefficient of determination (R²) revealed that the TM models were best suited for actual forecasting, even though R² in the TM model was lower than those of the FM and LM models.

CONCLUSIONS

The annual variation model in this study can be integrated with the daily pollen forecast model by controlling the annual pollen potential, and the accuracy of the daily forecast can be improved accordingly.

How does global warming contribute to disorders originating from an impaired epithelial barrier?

The epithelial barrier represents the point of contact between the host and the external environment. It is the first line of defense against external insults in the skin and in the gastrointestinal and upper and lower respiratory tracts. The steep increase in chronic disorders in recent decades, including allergies and autoimmune disorders, has prompted studies to investigate the immune mechanisms of their underlying pathogeneses, all of which point to a thought-provoking shared finding: disrupted epithelial barriers. Climate change with global warming has increased the frequency of unpredictable extreme weather events, such as wildfires, droughts, floods, and aberrant and longer pollination seasons, among many others. These increasingly frequent natural disasters can synergistically damage the epithelial barrier integrity in the presence of environmental pollution. A disrupted epithelial barrier induces proinflammatory activation of epithelial cells and alarmin production, namely, epithelitis. The "opened" epithelial barrier facilitates the entry of the external exposome into and underneath the epithelium, triggering an expulsion response driven by inflammatory cells in the area and chronic inflammation. These changes are associated with microbial dysbiosis with colonizing opportunistic pathogens and decreased commensals. These cellular and molecular events are key mechanisms in the pathogenesis of numerous chronic inflammatory disorders. This review summarizes the impact of global warming on epithelial barrier functions in the context of allergic diseases. Further studies in the impact of climate change on the dysfunction of the epithelial barriers are warranted to improve our understanding of epithelial barrier-related diseases and raise awareness of the environmental insults that pose a threat to our health.

The impact of air pollution on respiratory diseases in an era of climate change: A review of the current evidence

The impacts of climate change and air pollution on respiratory diseases present significant global health challenges. This review aims to investigate the effects of the interactions between these challenges focusing on respiratory diseases. Climate change is predicted to increase the frequency and intensity of extreme weather events amplifying air pollution levels and exacerbating respiratory diseases. Air pollution levels are projected to rise due to ongoing economic growth and population expansion in many areas worldwide, resulting in a greater burden of respiratory diseases. This is especially true among vulnerable populations like children, older adults, and those with pre-existing respiratory disorders. These challenges induce inflammation, create oxidative stress, and impair the immune system function of the lungs. Consequently, public health measures are required to mitigate the effects of climate change and air pollution on respiratory health. The review proposes that reducing greenhouse gas emissions contribute to slowing down climate change and lessening the severity of extreme weather events. Enhancing air quality through regulatory and technological innovations also helps reduce the morbidity of respiratory diseases. Moreover, policies and interventions aimed at improving healthcare access and social support can assist in decreasing the vulnerability of populations to the adverse health effects of air pollution and climate change. In conclusion, there is an urgent need for continuous research, establishment of policies, and public health efforts to tackle the complex and multi-dimensional challenges of climate change, air pollution, and respiratory health. Practical and comprehensive interventions can protect respiratory health and enhance public health outcomes for all.

Impact of meteorological parameters and air pollutants on airborne concentration of Betula pollen and Bet v 1 allergen

The intensity of birch pollen season is expressed by seasonal pollen integral (SPIn, the sum of the mean daily pollen concentration during the birch pollination period) and the amount of Bet v 1 allergen released per birch pollen grain expressed by pollen allergen potency (PAP). Betula pollen and Bet v 1 allergen were simultaneously measured in the air of Bratislava from 2019 to 2022 by using two Burkard traps (Hirst-type and cyclone) in order to evaluate the causes of the seasonal variation in the SPIn and PAP levels. The highest SPIn (19,975 pollen/m3) was observed in 2022 and the lowest one (1484 pollen/m3) in 2021. The average daily PAP level (4.0 pg Bet v 1/pollen) was highest in 2019 and lowest (2.5 pg Bet v 1/pollen) in 2020. We found that seasonal variation in SPIn was associated mainly with the changes in environmental conditions during the pre-season period, whereas the year-to-year variation in PAP levels was attributed to environmental conditions during both pre- and in-season periods. Our results indicate that rainy weather in June 2020 and cold overcast weather in January‒February 2021 resulted in low SPIn in 2021. On the other hand, dry weather in June 2021 and warm weather in January‒February 2022 resulted in high SPIn in 2022. The low average daily PAP level in 2020 was associated with (1) low levels of gaseous air pollutants in March, when the ripening of pollen takes place; (2) an earlier start of the birch main pollen season (MPS); and (3) dry weather during the MPS. On the other hand, high PAP level in 2019 was associated with higher levels of air pollutants in March and during the MPS.

Mechanisms of climate change and related air pollution on the immune system leading to allergic disease and asthma

Climate change is considered the greatest threat to global health. Greenhouse gases as well as global surface temperatures have increased causing more frequent and intense heat and cold waves, wildfires, floods, drought, altered rainfall patterns, hurricanes, thunderstorms, air pollution, and windstorms. These extreme weather events have direct and indirect effects on the immune system, leading to allergic disease due to exposure to pollen, molds, and other environmental pollutants. In this review, we will focus on immune mechanisms associated with allergy and asthma-related health risks induced by climate change events. We will review current understanding of the molecular and cellular mechanisms by which the changing environment mediates these effects.

Climate change and allergic diseases: An overview

Climate change has been regarded as a threat to the human species on the earth. Greenhouse gasses are leading to increased temperatures on Earth besides impacting the humanity. These atmospheric conditions have shown to alter the release pattern of pollens and can change the timing and magnitude of pollen release with flowering plants. As pollen is responsible for respiratory allergies in humans, so climate change can adversely affect human health in susceptible individuals. In this review, we highlight the association between climate change, increased prevalence and severity of asthma, and related allergic diseases. Increased air pollution can alter the production of local and regional pollen. This altered pattern depends on bioclimatic parameters. As simulated with a pollen-release model and future bioclimatic data, warmer temperatures lead to an increased pollen count in some specific locations and for longer periods. Thus, anticipation of a future allergic disease burden can help public health agencies in planning to develop strategies in mitigating the unprecedented health challenges expected in future years.

The scenario of the studies on ragweed (Ambrosia Sp.) and related issues from its beginning to today: a useful tool for future goals in a one health approach

BACKGROUND AND AIM

Airborne ragweed pollen is one of the agents of respiratory allergies in our changing environment. The monitoring of pollen is essential to manage pollen allergy and to improve its forecasting methods. Moreover, the control and fight against ragweed plants is important. Aim of this study is to understand the scenario of the studies on ragweed over time.

METHODS

We searched PubMed and Scopus for articles published until July 2022 reporting the words "ragweed". Articles written in all languages were included.

RESULTS

Scopus was the database with the highest number of published papers. Among the papers on ragweed, the papers citing the word "allergy" were 59.4% in PubMed and 37,6% in Scopus. The subject areas more addressed were medicine, immunology, genetics/molecular biology, but agricultural/biological sciences too and, interestingly, other subjects like social sciences, art, humanistic, etc.). Among the top 40 institutions supporting research, 8 were European, 4 Asian, 1 Russian and 21 were American, the other 6 were pharmaceutical companies.

CONCLUSIONS

This study shows a picture of the ragweed studies and some related subjects over time. A gap between the number of biomedical and not biomedical issues was evident. There is a need for greater involvement of institutions into support of knowledge and fight ragweed. The results will provide a useful tool to identify future goals in a global approach of ragweed related issues.