LISBON, Portugal, June 5, 2019 /PRNewswire/ -- Approximately 7 million people die prematurely each year from air pollution (WHO). Besides its impact on global health, air pollution also contributes to climate change. EAACI supports World Environment Day, a United Nations-led event which this year tackles the theme of air pollution. Joining this call to action to combat one of the greatest environmental challenges of our time, a variety of sessions at the EAACI Annual Congress 2019 explores existing links between pollution, allergic diseases and asthma.
"We must join forces and be advocates for the air pollution battle. Health professionals are getting impatient. We want to treat our patients, but we also want to prevent the causes of the disease," says Maria Neira, Director Department of Public Health and Environment, World Health Organisation in a plea to EAACI Annual Congress 2019 participants.
The first peak of pollen-related allergies affecting the respiratory tract arose after the industrial revolution and coincided with worsening air quality. Since then, exposure to environmental pollution is considered to be partially responsible for the increased prevalence and severity of allergic diseases. Some pollutants, such as CO2, boost plant growth and increase pollination. In ragweed, CO2 enhances ragweed biomass and increases pollen output by 60 up to 90 percent.
Besides, CO2 contributes to the rise in global temperature which also has implications for allergic patients. "Depending where you live, higher temperatures may result in more plant growth. A shift in allergen exposure from pollen is to be expected, the direction depends on where you live," says Jeroen Buters, toxicologist from TUM and past Chair of the EAACI Working Group on Aerobiology and Pollution.
Air pollutants such as nitrogen oxides, ozone, diesel exhaust particles and volatile organic compounds also make pollen more allergenic. Birch and ryegrass pollen collected along high traffic roads was found to be richer in allergens than pollen in urban parks.
Exposure of pollen to pollutants can also crack its cell wall structure, resulting in expulsion of allergenic microparticles that can easily penetrate airways and even reach the lower respiratory tract.
Research also points towards a link between asthma and air pollution. Prenatal exposure has been shown to impact on the developing lung and immune system and thus increase the risk of wheezing and asthma. Additionally, air pollution, especially traffic-related, can increase the chances of developing asthma in adults.
"Exposure to particulates from diesel vehicle emissions is linked to asthma and allergies. Although everyone is susceptible to diesel pollution, children, the elderly, and individuals with preexisting respiratory conditions are the most vulnerable. As vehicles equipped with advanced diesel emissions controls will enter the market, it will be important to ensure that emission levels are maintained throughout the life of the vehicle by periodic testing," says Isabella Annesi-Maesano, INSERM.
Robust scientific evidence on how air quality can simultaneously modify the concentration of airborne pollen, and its allergenicity, lead to allergic reactions and exacerbate response to allergens is available. However, importantly, various other genetic and environmental factors may play additional roles in development of allergic diseases including asthma.
In this light, the EAACI White Paper 2018, which sets quality standards and research priorities for allergic diseases and asthma suggests: "Exposome-focused projects are needed to examine the complex interplay of environment and genetics to determine the most cost-effective interventions for reducing the risk of allergic disease".
The European Academy of Allergy and Clinical Immunology (EAACI) is an association of clinicians, researchers and allied health professionals founded in 1956. EAACI is dedicated to improving the health of people affected by allergic diseases. With more 11,000 members from 122 countries and over 75 National Allergy Societies, EAACI is the primary source of expertise in Europe for all aspects of allergy.
SOURCE European Academy for Allergy and Clinical Immunology (EAACI)