Climate, Carbon Dioxide, and Plant-Based Aero-Allergens: A Deeper Botanical Perspective

Long-term pollen season trends of Fraxinus (ash), Quercus (oak) and Ambrosia artemisiifolia (ragweed) as indicators of anthropogenic climate change impact

The ongoing climatic change, together with atmospheric pollution, influences the timing, duration and intensity of pollen seasons of some allergenic plant taxa. To study these influences, we correlated the trends in the pollen season characteristics of both woody (Fraxinus, Quercus) and herbaceous (Ambrosia) taxa from two pollen monitoring stations in Slovakia with the trends in meteorological factors and air pollutants during the last two decades. In woody species, the increased temperature during the formation of flower buds in summer and autumn led to an earlier onset and intensification of next year's pollen season, especially in Quercus. The increase of relative air humidity and precipitation during this time also had a positive influence on the intensity of the pollen season of trees. The pollen season of the invasive herbaceous species Ambrosia artemisiifolia was prolonged by increased temperature and humidity during the summer and autumn of the same year, which extended the blooming period and delayed the end of the pollen season. From the studied air pollutants, only three were found to correlate with the intensity of the pollen season of the studied taxa, CO - positively and SO2 and NO2 - negatively. It is important to study these long-term trends since they not only give us valuable insight into the response of plants to changing conditions but also enable the prognosis of the exacerbations of pollen-related allergenic diseases.

Respiratory Health Effects of Air Pollutants

Air pollution is a risk factor for asthma and respiratory infection. Avoidance of air pollution is the best approach to mitigating the impacts of pollution. Personal preventive strategies are possible, but policy interventions are the most effective ways to prevent pollution and its effect on asthma and respiratory infection.

A Review of Pollen Counting Networks: From the Nineteenth Century into the Twenty-first Century

PURPOSE OF REVIEW

Pollen is enormously important to the human experience. As pollen became germane to human health in the late nineteenth century, methods for pollen collection and measurement were developed. Techniques were standardized and pollen counting networks were established in many parts of the world during the middle to late part of the twentieth century. With some notable exceptions, the technology of the 1950s and 1960s is presently employed to create the current pollen counting networks. Pollen counting networks in the past faced substantial challenges. Pollen counting networks using the same technology as the past face the same challenges.

RECENT FINDINGS

As we move into the twenty-first century, automated pollen counting technology enables pollen counting networks to be robust, available, scalable, self-perpetuating, and able to meet modern demands. Automated pollen measurement networks present a promising path towards a more informed, data-driven, and effective approach to managing allergens, improving crop yields, and minimizing human suffering caused by pollen. By empowering individuals with comprehensive pollen data, a feat not possible with manual counting, we can help people make informed decisions and take proactive measures to minimize exposure to allergens and improve their well-being.

The Role of Climate Change in Asthma

Human activity and increased use of fossil fuels have led to climate change. These changes are adversely affecting human health, including increasing the risk of developing asthma. Global temperatures are predicted to increase in the future. In 2019, asthma affected an estimated 262 million people and caused 455,000 deaths. These rates are expected to increase. Climate change by intensifying climate events such as drought, flooding, wildfires, sand storms, and thunderstorms has led to increases in air pollution, pollen season length, pollen and mold concentration, and allergenicity of pollen. These effects bear implications for the onset, exacerbation, and management of childhood asthma and are increasing health inequities. Global efforts to mitigate the effects of climate change are urgently needed with the goal of limiting global warming to between 1.5 and 2.0 °C of preindustrial times as per the 2015 Paris Agreement. Clinicians need to take an active role in these efforts in order to prevent further increases in asthma prevalence. There is a role for clinician advocacy in both the clinical setting as well as in local, regional, and national settings to install measures to control and curb the escalating disease burden of childhood asthma in the setting of climate change.

25-year retrospective longitudinal study on seasonal allergic rhinitis associations with air temperature in general practice

Due to climate change, air temperature in the Netherlands has gradually increased. Higher temperatures lead to longer pollen seasons. Possible relations between air temperature and increased impact of seasonal allergic rhinitis (SAR) in general practice have not been investigated yet. We explored trends in timing of frequent seasonal allergic rhinitis presentation to general practitioners (GPs) over 25 years and explored associations with air temperature. We performed a retrospective exploratory longitudinal study with data from our Family Medicine Network (1995-2019), including all SAR patients and their GP-encounters per week. We determined patients' GP-consultation frequency. Every year we identified seasonal periods with substantial increase in SAR related encounters: peak-periods. We determined start date and duration of the peak-period and assessed associations with air temperature in the beginning and throughout the year, respectively. The peak-period duration increased by a mean of 1.3 days (95% CI 0.23-2.45, P = 0.02) per year throughout the study period. Air temperature between February and July showed a statistically significant association with peak-period duration. We could not observe direct effects of warmer years on the start of peak-periods within distinct years (P = 0.06). SAR patients' contact frequency slightly increased by 0.01 contacts per year (95% CI 0.002-0.017, P = 0.015). These longitudinal findings may help to facilitate further research on the impact of climate change, and raise awareness of the tangible impact of climate change in general practice.

Modeling past and future spatiotemporal distributions of airborne allergenic pollen across the contiguous United States

Exposures to airborne allergenic pollen have been increasing under the influence of changing climate. A modeling system incorporating pollen emissions and atmospheric transport and fate processes has been developed and applied to simulate spatiotemporal distributions of two major aeroallergens, oak and ragweed pollens, across the contiguous United States (CONUS) for both historical (year 2004) and future (year 2047) conditions. The transport and fate of pollen presented here is simulated using our adapted version of the Community Multiscale Air Quality (CMAQ) model. Model performance was evaluated using observed pollen counts at monitor stations across the CONUS for 2004. Our analysis shows that there is encouraging consistency between observed seasonal mean concentrations and corresponding simulated seasonal mean concentrations (oak: Pearson = 0.35, ragweed: Pearson = 0.40), and that the model was able to capture the statistical patterns of observed pollen concentration distributions in 2004 for most of the pollen monitoring stations. Simulation of pollen levels for a future year (2047) considered conditions corresponding to the RCP8.5 scenario. Modeling results show substantial regional variability both in the magnitude and directionality of changes in pollen metrics. Ragweed pollen season is estimated to start earlier and last longer for all nine climate regions of the CONUS, with increasing average pollen concentrations in most regions. The timing and magnitude of oak pollen season vary across the nine climate regions, with the largest increases in pollen concentrations expected in the Northeast region.