Neighborhood disadvantage and the back-to-school epidemic of viral-associated asthma exacerbations.

Background: Rates of viral-associated asthma exacerbations typically increase when children return to school after the summer holiday. The effect of neighborhood disadvantage on this back-to-school increase in viral-associated asthma exacerbations is unknown.

Objective: We aimed to evaluate the effect of neighborhood disadvantage on the back-to-school increase in asthma-related emergency department (ED) visits.

Fungal Spore Seasons Advanced Across the US Over Two Decades of Climate Change.

Phenological shifts due to climate change have been extensively studied in plants and animals. Yet, the responses of fungal spores-organisms important to ecosystems and major airborne allergens-remain understudied. This knowledge gap limits our understanding of their ecological and public health implications.

Exploring Community Co-Creation in Tree Planting and Heat-Related Health Interventions: A Qualitative Study.

Climate-amplified extreme heat events are particularly dangerous for city dwellers. Nature-based solutions such as urban greening may serve as an effective preventative strategy against extreme heat. Driven by historical injustices such as redlining, disadvantaged communities often face limited green space and a heightened risk of vulnerability to extreme heat in urban environments.

Pollen and viruses contribute to spatio-temporal variation in asthma-related emergency department visits.

Background: Asthma exacerbations are an important cause of emergency department visits but much remains unknown about the role of environmental triggers including viruses and allergenic pollen. A better understanding of spatio-temporal variation in exposure and risk posed by viruses and pollen types could help prioritize public health interventions.

Objective: Here we quantify the effects of regionally important Cupressaceae pollen, tree pollen, other pollen types, rhinovirus, seasonal coronavirus, respiratory syncytial virus, and influenza on asthma-related emergency department visits for people living near eight pollen monitoring stations in Texas.

Volunteer-contributed observations of flowering often correlate with airborne pollen concentrations.

Characterizing airborne pollen concentrations is crucial for supporting allergy and asthma management; however, pollen monitoring is labor intensive and, in the USA, geographically limited. The USA National Phenology Network (USA-NPN) engages thousands of volunteer observers in regularly documenting the developmental and reproductive status of plants. The reports of flower and pollen cone status contributed to the USA-NPN's platform, Nature's Notebook, have the potential to help address gaps in pollen monitoring by providing real-time, spatially explicit information from across the country.

Do upper respiratory viruses contribute to racial and ethnic disparities in emergency department visits for asthma?

Background: There are marked disparities in asthma-related emergency department (ED) visit rates among children by race and ethnicity. Following the implementation of coronavirus disease 2019 (COVID-19) prevention measures, asthma-related ED visits rates declined substantially. The decline has been attributed to the reduced circulation of upper respiratory viruses, a common trigger of asthma exacerbations in children.

Within city spatiotemporal variation of pollen concentration in the city of Toronto, Canada.

Background: The exacerbation of asthma and respiratory allergies has been associated with exposure to aeroallergens such as pollen. Within an urban area, tree cover, level of urbanization, atmospheric conditions, and the number of source plants can influence spatiotemporal variations in outdoor pollen concentrations.

Objective: We analyze weekly pollen measurements made between March and October 2018 over 17 sites in Toronto, Canada.

Urban-scale variation in pollen concentrations: A single station is insufficient to characterize daily exposure.

Epidemiological analyses of airborne allergenic pollen often use concentration measurements from a single station to represent exposure across a city, but this approach does not account for the spatial variation of concentrations within the city. Because there are few descriptions of urban-scale variation, the resulting exposure measurement error is unknown but potentially important for epidemiological studies. This study examines urban scale variation in pollen concentrations by measuring pollen concentrations of 13 taxa over 24-hr periods twice weekly at 25 sites in two seasons in Detroit, Michigan.

Pollen production for 13 urban North American tree species: Allometric equations for tree trunk diameter and crown area.

Estimates of airborne pollen concentrations at the urban scale would be useful for epidemiologists, land managers, and allergy sufferers. Mechanistic models could be well suited for this task, but their development will require data on pollen production across cities, including estimates of pollen production by individual trees. In this study, we developed predictive models for pollen production as a function of trunk size, canopy area, and height, which are commonly recorded in tree surveys or readily extracted from remote sensing data.

Allergenic pollen production across a large city for common ragweed ().

Predictions of airborne allergenic pollen concentrations at fine spatial scales require information on source plant location and pollen production. Such data are lacking at the urban scale, largely because manually mapping allergenic pollen producing plants across large areas is infeasible. However, modest-sized field surveys paired with allometric equations, remote sensing, and habitat distribution models can predict where these plants occur and how much pollen they produce.

Effect of intra-urban temperature variation on tree flowering phenology, airborne pollen, and measurement error in epidemiological studies of allergenic pollen.

Temperature gradients in cities can cause inter-neighborhood differences in the timing of pollen release. However, most epidemiological studies examining allergenic pollen utilize daily measurements from a single pollen monitoring station with the implicit assumption that the measured time series of airborne pollen concentrations applies across the study areas, and that the temporal mismatch between concentrations at the counting station and elsewhere in the study area is negligible. This assumption is tested by quantifying temperature using satellite imagery, observing flowering times of oak (Quercus) and mulberry (Morus) trees at multiple sites, and collecting airborne pollen.

The contrasting effects of short-term climate change on the early recruitment of tree species.

Predictions of plant responses to climate change are frequently based on organisms' presence in warmer locations, which are then assumed to reflect future performance in cooler areas. However, as plant life stages may be affected differently by environmental changes, there is little empirical evidence that this approach provides reliable estimates of short-term responses to global warming. Under this premise, we analyzed 8 years of early recruitment data, seed production and seedling establishment and survival, collected for two tree species at two latitudes.

Foliar damage beyond species distributions is partly explained by distance dependent interactions with natural enemies.

Plant distributions are expected to shift in response to climate change, and range expansion dynamics will be shaped by the performance of individuals at the colonizing front. These plants will encounter new biotic communities beyond their range edges, and the net outcome of these encounters could profoundly affect colonization success. However, little is known about how biotic interactions vary across range edges and this has hindered efforts to predict changes in species distributions in response to climate change.

The effects of invertebrate herbivores on plant population growth: a meta-regression analysis.

Over the last two decades, an increasing number of studies have quantified the effects of herbivory on plant populations using stage-structured population models and integral projection models, allowing for the calculation of plant population growth rates (λ) with and without herbivory. In this paper, I assembled 29 studies and conducted a meta-regression to determine the importance of invertebrate herbivores to population growth rates (λ) while accounting for missing data. I found that invertebrate herbivory often induced important reductions in plant population growth rates (with herbivory, λ was 1.

Heterogeneity in ragweed pollen exposure is determined by plant composition at small spatial scales.

Pollen allergies are one of the most common health problems in the United States and over 20% of Americans are sensitized to the pollen produced by common ragweed (Ambrosia artemisiifolia L.). Despite the importance of allergenic pollen to public health, no research has linked land use and plant populations to spatial heterogeneity in airborne pollen concentrations.