A Review of the Respiratory Health Burden Attributable to Short-Term Exposure to Pollen

Abstract

Respiratory diseases such as asthma, allergic rhinitis (AR) and chronic obstructive pulmonary disease (COPD) affect millions worldwide and pose a significant global public health burden. Over the years, changes in land use and climate have increased pollen quantity, allergenicity and duration of the pollen season, thus increasing its impact on respiratory disease. Many studies have investigated the associations between short-term ambient pollen (i.e., within days or weeks of exposure) and respiratory outcomes. Here, we reviewed the current evidence on the association between short-term outdoor pollen exposure and thunderstorm asthma (TA), asthma and COPD hospital presentations, general practice (GP) consultations, self-reported respiratory symptoms, lung function changes and their potential effect modifiers. The literature suggests strong evidence of an association between ambient pollen concentrations and almost all respiratory outcomes mentioned above, especially in people with pre-existing respiratory diseases. However, the evidence on sub-clinical lung function changes, COPD, and effect modifiers other than asthma, hay fever and pollen sensitisation are still scarce and requires further exploration. Better understanding of the implications of pollen on respiratory health can aid healthcare professionals to implement appropriate management strategies.

Is exposure to pollen a risk factor for moderate and severe asthma exacerbations?

“…Pollen is one of the main risk factors for the development and the aggravation of allergic rhinitis 1,2 and more recently has been associated also with asthma. 3 Pollen rhinitis and asthma are assumed to increase along with their socioeconomic impact 4 as pollen aeroallergens and allergenicity are influenced by climate, humidity, temperature, and air pollution. [5][6][7][8] Overall, sparse studies have focused on the links between pollen exposure and asthma events.…”

Association between grass, tree and weed pollen and asthma health outcomes in Adelaide, South Australia: a time series regression analysis

“…While a recent review confirmed the significance of short-term exposure to pollen to the respiratory health burden, it also noted that large time series studies are still necessary to detect area specific associations and possible synergistic effects. 23 This study was conducted to bring about evidence of timing of the asthma and pollen relationship in Adelaide, and to find out how this relates to pollen of grasses, weeds and trees in children and adults and their asthma exacerbation. Hence, this study sets out on a risk assessment procedure delivering risk association measures by months for grass, weed and tree pollen for children and adults, to guide the appropriate content and timing of pollenrelated public health initiatives.…”

“…This adds another layer to the pollen quandary and the need to ask further questions. While a recent review confirmed the significance of short-term exposure to pollen to the respiratory health burden, it also noted that large time series studies are still necessary to detect area specific associations and possible synergistic effects 23…”

Virtual Impactor-Based Label-Free Pollen Detection using Holography and Deep Learning

“…Exposure to bioaerosols has been related to a wide range of health issues. 3,4 Some bio-aerosols cause irritation and allergic reactions, such as pollen; 5,6 some others, such as fungal and bacterial 7,8 PM, can spread infectious and respiratory diseases. For example, bio-aerosols served as an important transmission route during the COVID-19 pandemic.…”

“…Bio-aerosols can easily enter the respiratory tract during inhalation due to their microscopic size. Exposure to bio-aerosols has been related to a wide range of health issues. , Some bio-aerosols cause irritation and allergic reactions, such as pollen; , some others, such as fungal and bacterial , PM, can spread infectious and respiratory diseases. For example, bio-aerosols served as an important transmission route during the COVID-19 pandemic. , They may also lead to an increased risk of cancer. ,, Conventional sensing of bio-aerosols includes two steps: the aerosols are first sampled using, for example, an impinger, a cyclone, an impactor, or a filter, , and then analyzed in a central lab under a microscope with fluorescence labeling or through a culture-based procedure by a microbiology expert .…”