Understanding pollen seasons and hay fever. (by Diego Fdez-Sevilla, PhD)
Pollen seasons and Hay fever.
Pollen from grasses, trees, and weeds is the wonderful substance that allow plants to reproduce, but it is also responsible for numerous allergic reactions people experience. Although pollen is found naturally in the air, human activities and choices can increase the amount of pollen in our air, and in turn, can cause people to have more severe allergic reactions. Because human activities can increase the amount of pollen in our air and cause adverse health effects, there are some considerations on viewing pollen as an air pollutant.
People commonly treat their allergies by avoiding situations where they might have an attack, by using dehumidifiers and air filters. But, by becoming familiar with the source of your allergies, you can also begin to make choices that can prevent the severity of your attacks.
The number of pollen particles released into the air are studied and measured in the field of “Aerobiology” by performing “pollen counts”. In my career as Environmental Biologist I spent the early years as Lab Technician in the field of Aerobiology carrying out daily pollen counts with a microscope before I began to use the data to perform research at PhD level into the dynamics behind the aerodynamic behaviour of pollen in the atmosphere.
Pollen counts tell you the number of pollen grains per cubic meter of air. They can also tell you which tree, grass, or plant the pollen came from. Different plants and trees produce different amounts of pollen and knowing which plants are the largest contributors to your allergies can influence what flowers and trees you and your community chose to plant.
The flowering time of higher plants are events that come periodically in each season, but the time of blooming may differ from year to year, in different geographic locations. Based on differences recorded in several years of observations in airborne pollen, pollen calendars are drawn as an aid to allergy diagnosis and management.
Pollen from trees, weeds and grasses are the primary culprits behind seasonal allergies. Spring allergies are typically from tree pollen, whereas summer allergies usually come from grasses, and then weed pollens dominate the airways during late summer and fall. Without allergy testing, it’s nearly impossible to determine which offenders are causing your wheezes and sneezes, but the time and season may give you some clues. If you’ve noticed your allergies seem to be getting worse lately, you’re not the only one.
In an article by Dr. Mercola there is helpful and useful information to understand how and why do allergies develop. (“Allergy Season Hits U.S. with a Vengeance articles.“)
How and Why Do Allergies Develop?
(Dr. Mercola) Allergies are your body’s reaction to allergens (particles your body considers foreign), a sign that your immune system is working overtime. The first time your body encounters an allergen, your plasma cells release IgE (immunoglobulin E), an antibody specific to that allergen. IgE attaches to the surface of your mast cells. Mast cells are found in great numbers in your surface tissues (i.e., those with close proximity to the external environment, such as in your skin and in the mucous membranes of your nose), where they help mediate inflammatory responses.
Mast cells release a number of important chemical mediators, one of which is histamine.
So, the second time your body encounters a particular allergen, within a few minutes the mast cells become activated and release a powerful cocktail of histamine, leukotrienes, and prostaglandins, which trigger the entire cascade of symptoms you associate with allergies: sneezing, runny nose, sore throat, hacky cough, itchy eyes, etc. Histamine can cause your airways to constrict, like with asthma, or cause blood vessels to become more permeable, leading to fluid leakage or hives.
Leukotrienes cause hypersecretion of mucus, which you commonly experience as a runny nose or increased phlegm.
Pollen is an extremely common mast cell activator, but other agents can trigger these processes as well. Mold spores, dust, airborne contaminants, dust mites, pet dander, cockroaches, environmental chemicals, cleaning products, personal care products and foods can all cause allergic reactions. Every person is different in what he or she reacts to. And, just because you haven’t reacted to something in the past doesn’t mean you won’t react to it in the future—you can become sensitized at any point in time.
The good news is, many people “outgrow” their seasonal allergies by the time they reach the age of 60 to 70, when their immune systems become less reactive.
Besides pollen, household chemicals such as triclosan and bisphenol-A (BPA) can aggravate or even cause allergies. Scientists from the University of Michigan recently found that people who commonly used triclosan products were more likely to suffer from allergies or hay fever. This is why it is NOT a good idea to use antibacterial soap—which leads us right into one of the theories about why allergies have become such a problem today.
You will find more information on this topic in a post I wrote about it “Allergies, asthma and the environment (by Diego Fdez-Sevilla)”
Influence of climate in changing pollen seasons.
There is also an intention to bring awareness to public domain on that climate warming is becoming to be recognised as a factor increasing pollen concentrations. This is due to that plants elongate their pollen seasons starting earlier as temperature raises earlier through the year, and ending later as temperature drops later over the year. And this is more evident in highly urbanised environments since higher concentrations of CO2 and the materials used in construction, absorb radiation through the day and keep temperatures higher through the night that in rural areas. It is called Urban Heat Island Effect.
Assessment between pollen seasons in areas with different urbanization level related to local vegetation sources and differences in allergen exposure. Rodríguez-Rajo, F.J., Fdez-Sevilla, D., Stach, A. et al. Aerobiologia (2010) 26: 1. doi:10.1007/s10453-009-9138-2
(Dr. Mercola) There are now a number of studies linking changes in climate with increasingly long and severe allergy seasons. In fact, springtime is arriving 10 to 14 days earlier than it did 20 years ago, which results in higher pollen levels for longer periods of time. A new USDA study published in the Proceedings of the National Academy of Health Sciences confirms that hay fever season is becoming more intense and lasting longer. How do altered weather patterns contribute to allergies?
Clifford Bassett, MD, medical director of Allergy and Asthma Care of New York sheds some light on this by using the example of ragweed, a very common allergen. Under normal circumstances, a single ragweed plant produces 1 million pollen grains. However, a CO2-rich environment boosts that number to 3 to 4 million grains. And ragweed is only ONE of the weed species making you miserable—there are many others that scientists expect to become “supercharged” by Earth’s warming climate.
But here is something you probably don’t associate with allergies: thunderstorms.
Stanley Fineman, MD (president of the American College of Allergy, Asthma, and Immunology) reports that quite a few studies have linked thunderstorms to a greater incidence of asthma-related hospitalizations. The phenomenon even has a name—it’s called “thunderstorm asthma,” and physicians believe it has something to do with all the pollen and dust that thunderstorms stir up. Thunderstorms appear to be increasing in both frequency and severity. These trends are not likely to reverse themselves anytime soon, so it’s time to arm yourself with some effective allergy fighters if you are one of the 60 million Americans afflicted.”
Elizabeth Landau’s article about the influence of climate warming on pollen seasons “Global warming brings on more pollen” points out that research presented at the American College of Allergy, Asthma and Immunology in November suggests that pollen counts are going to get a lot worse in the next 30 years. Dr. Leonard Bielory showed predictions that pollen counts will more than double by 2040.
Bielory is part of an ongoing study at Rutgers University modeling what climate change has in store for pollen. The study analyzes various allergenic plants being grown in climate chambers modeling future conditions, and researchers are incorporating factors including weather patterns and changes in precipitation and temperature. Pollen counts averaged 8,455 in the year 2000, and by 2040 they are expected to reach 21,735, according to this model. And the allergy season will begin earlier each year, too.
Linda Marsa extends the coverage on this topic in her article “Links to Climate Change and Longer, Stronger Allergy Seasons” | Reporting on Health reporting onhealth.org
One intriguing study done by U.S. Department of Agriculture scientists revealed that higher concentrations of carbon dioxide in the air stimulates plant growth and the carbon-enriched pollen— CO2 is, after all, a driver of photosynthesis—is more damaging because it contains more of the chemicals that cause allergic reactions.
The plants grown under conditions that simulated CO2levels that are projected by mid-century, allergens rose by 60 percent. Carbon dioxide is a food source for plants, which convert it into sugars and carbohydrates. But not all plants respond the same way, and noxious weeds—as well as vines like poison ivy and kudzu—react much more strongly to higher CO2than other types of plants do, Lewis Ziska, a USDA plant physiologist who led this research team, told me when I interviewed him for my book, Fevered. As a consequence, we see not only more growth, but also potentially more virulent chemicals within the plants.
“When we look at climate change, we think of it as this esoteric thing that will happen to our grandkids,” says the USDA’s Lewis Ziska. “But what this research shows is that it is already happening and it’s affecting us right now.”
Tips to cope with hay fever
- Reduce your stress levels as they are linked to the severity of symptoms.
- Keep exercising. Hay fever sufferers who exercise most have the mildest symptoms.
- Change your clothes after you’ve been outside or take your clothes off before entering the bedroom.
- Wash your hair. Pollen clings to your hair and can then transfer to your pillow at bedtime.
- Wear sunglasses – wraparounds are best – to protect eyes from pollen.
- Buy low allergenic plants and flowers.
- Be house proud. Vacuum and dust with a damp cloth regularly.
- Close house and car windows to avoid pollen getting in.
- Avoid parks or fields in early evening when a lot of pollen floats at nose level.
My last advice. First of all, identify the type of pollen and the plants you are allergic to. Talk with your doctor and make some tests.
Secondly, in every country there are scientists (Aerobiologists like me) doing research in a field called Aerobiology which, among other things, covers the release and transport of pollen in the atmosphere, offering forecast and updates on local pollen seasons and concentrations. So, once you know the pollen type you have to avoid, check online for information, the pollen season calendar in your area, forecasts, levels of concentration in daily and hourly bases in your area and think ahead about how you can minimize your exposure.
Where to get more information
There are many scientists around the world involved in this type of research who you should be able to contact through their institutions willing to help offering information. Even-though Aerobiology is an unknown discipline for many it covers the study of biological aerosol particles which are about 25% of the particles suspended in air. Aerobiology is often considered the ‘microbiology’ of the atmosphere. It represents the presence and movement of biological particles (bioaerosols), or products of organisms within the atmosphere or within indoor environments. Aerobiology is frequently referred to as ‘the atmospheric soup’. It is closely allied with biometeorology, an interdisciplinary study of the interactions between atmospheric processes and living organisms such as plants, animals, and humans. By its very nature, Aerobiology is interdisciplinary with meteorology and aerosol physics at its core and with applications in climatology, public health, allergy, immunology, palynology, microbiology, agriculture, ecosystem health evaluation and as bioindicator in climate change.
Allergic diseases are amongst the most common chronic disorders worldwide. Today, more than 300 million of the population is known to suffer from one or other allergic ailments affecting the socio-economic quality of life. Major causative agents implicated are pollen grains, fungal spores, dust mites, insect debris, animal epithelia, etc. Several aerobiological studies have been conducted in different parts of the world to ascertain aerial concentration and seasonality of pollen grains and fungi. Especially from clinical point of view, it is important to know the details about the pollen season and pollen load in the atmosphere. The flowering time of higher plants are events that come periodically in each season, but the time of blooming may differ from year to year, in different geographic locations. Based on differences recorded in several years of observations in airborne pollen, pollen calendars are drawn as an aid to allergy diagnosis and management.
Nowadays we live in a world full of information and yet, many times it is a struggle to find what it is useful for our needs without some guidance. Science is a language which serves for more things than to communicate between ivory towers. It is becoming more evident than ever that the knowledge generated has to reach further than scientific papers and come across all forms of communication. And scientists are willing to share what they know and show how useful is what they do. Some examples you will find them in the digital media thanks to senior scientists involved in sharing what they know.
Here I leave the links to two articles where two lead scientists contribute with their expertise in the subject:
Prof Jean Emberlin (chief scientist at AllergyUK) , addressing the situation in UK and Europe Hay fever tips: How to treat summer problem as Britain readies itself for epidemic By Michele O’Connor. May 15, 2014
Estelle Levetin, the chair of the biology department at the University of Tulsa, addressing the situation in USA. Brutal Allergy Season Is Ahead. Blame the Polar Vortex. It’s going to be a hell of a pollen season.”—By Molly Redden| Tue Apr. 15, 2014
I hope this information helps.
You can also contact me at my email: email@example.com