Mapping allergenic pollen vegetation in UK to study environmental exposure and human health

Abstract

Allergenic pollen is produced by the flowers of a number of trees, grasses and weeds found throughout the UK. Exposure to such pollen grains can exacerbate pollen-related asthma and allergenic conditions such as allergic rhinitis (hay fever). Maps showing the location of these allergenic taxa have many applications: they can be used to provide advice on risk assessments; combined with health data to inform research on health impacts such as respiratory hospital admissions; combined with weather data to improve pollen forecasting systems; or as inputs to pollen emission models. In this study we present 1 km resolution maps of 12 taxa of trees, grass and weeds found in the UK. We have selected the main species recorded by the UK pollen network. The taxa mapped in this study were: Alnus (alder), Fraxinus (ash), Betula (birch), Corylus (hazel), Quercus (oak), Pinus (pine) and Salix (willow), Poaceae (grass), Artemisia (mugwort), Plantago (plantain), Rumex (dock, sorrels) and Urtica (nettle). We also focus on one high population centre and present maps showing local level detail around the city of London. Our results show the different geographical distributions of the 12 taxa of trees, weeds and grass, which can be used to study plants in the UK associated with allergy and allergic asthma. These maps have been produced in order to study environmental exposure and human health, although there are many possible applications. This novel method not only provides maps of many different plant types, but also at high resolution across regions of the UK, and we uniquely present 12 key plant taxa using a consistent methodology. To consider the impact on human health due to exposure of the pollen grains, it is important to consider the timing of pollen release, and its dispersal, as well as the effect on air quality, which is also discussed here.

Trends in the prescribing of topical nasal agents Using an NHS England data base

“…Prescription rates peaked during the months of high environmental pollen over the last 5 years (April, May, June and July). Highest rates of pollen emissions for a variety of plant taxa including Grass, Dock, Sorrell, Nettle, Plantain and Mugwort are found in June and July . This reflects our finding that the months of June and July have consistently the highest levels of prescribing rates over the last 5 years, as it is likely the incidence of a AR peaks in these months across England.…”

“…A recent study investigating vegetation taxa which contribute the highest to allergic pollen emission in the UK has shown results which do not correspond with our findings; there is not a higher density of pollen-producing taxa in the eastern/eastern coastal districts of England. 10 Furthermore, average pollen rates produced by the met office reveal the highest emissions to be in southern and central England, not in eastern districts of England. 11 Therefore, this geographical variation cannot solely be explained by pollen exposure.…”

“…An overall fall in prescription rate between high and low pollen season is expected; in November, none of the most common plant taxa responsible for allergic rhinitis have peak pollen emissions. 10 Despite this, during low pollen season, there was a large difference in mean prescription rate between the highest and lowest 40 prescribing CCG's. Additionally, urban districts prescribed significantly less items per 1000 patients compared with non-urban areas (p ≤ .001).…”

Beyond Climate Change and Health: Integrating Broader Environmental Change and Natural Environments for Public Health Protection and Promotion in the UK

“…To address this research gap, studies conducted by the HPRU in Environmental Change and Health have focused on mapping the location of allergenic plant species across the UK [84] and relating pollen and land cover with health outcomes, including asthma exacerbation-related hospital admissions [85]. Results of this latter study showed that daily concentrations of grass pollen were significantly associated with adult hospital admissions for asthma in London, with a 4-5 day lag from increased pollen levels to hospital admissions.…”

Temperate grass allergy season defined by spatio-temporal shifts in airborne pollen communities

“…(Vernal grasses). However, it is unknown whether particular grass species contribute more to the prevalence of allergic symptoms and related diseases than others [11]. Whilst some grasses have been identified as more allergenic than others in vitro (triggering higher levels of Immunoglobulin E (IgE) antibody production), there is a high degree of cross-reactivity between grass species [12].…”