This Spring’s Pollen Festival
• by Dr. Sarah D. Oktay – Managing Director UMass Boston Nantucket Field Station •
An allergy is a heightened sensitivity to a foreign substance called an allergen that causes the body’s defense system (the immune system) to overreact when defending itself. This defense system was set into place evolutionally to provide a mechanism for our body to combat serious threats like bacteria or viruses. Allergy symptoms can be relatively mild to severe and even life threatening. Common allergies include eczema, hives, “hay fever”, and asthma. You can get an allergic reaction from food, pet dander, airborne pollen, and the venom of stinging insects, such as wasps and bees. Treatments for allergies include avoidance, use of anti-histamines, steroids or other medications, and immunotherapy to desensitize the allergic response.
We first start becoming aware of hay fever season when we see blankets of pine pollen appear. It is the harbinger of spring and the most noticeable of pollen deposited, sometimes leaving piles of yellow pollen dust on parked cars. These pollen particles, although they can wreak havoc on some, are relatively large and harder to inhale so they do not have the distinction of providing the greatest sneeze for the buck. Instead, it is microscopic particles in the spring air that are hell-bent on causing misery. Most seasonal allergies are caused by smaller tree pollen and mold spores, according to the American Academy of Allergy, Asthma & Immunology (http://www.aaaai.org/home.aspx retrieved May 19th 2013). More than 60 million Americans suffer from allergic rhinitis, according to the academy. That means when they inhale something they are allergic to, they suffer symptoms in the nose and eyes. When the trigger of the reaction is pollen, the person is said to have “hay fever.” Many of the biggest spring pollen producing plants include cedars, birches, oaks, elms, junipers, red alder, and sweet vernal grass. Late summertime/early fall is the time for ragweed allergies which can occur anywhere but are most prevalent in the rural eastern parts of the country and in the Midwest.
This spring has been a banner year for pollen with Eastern red cedar pollen dominating the spring, and tree pollen and weed pollen filling people’s airways even as I speak. I had not realized how dominant certain plant species can be across the U.S. until I attended a conference in late April and heard a colleague from Oklahoma commenting on the red cedar (Juniperus virginiana) pollen causing allergy symptoms even for typically immune people. People in the Midwest and specifically Texas and Oklahoma have started to campaign against the spread of mountain cedar and eastern red cedar because of the misery they spread via pollen. Tree pollen was listed as the worst offender for Nantucket on a couple of the allergy watch lists. And according to the pollen library (http://www.pollenlibrary.com/Specie/Juniperus+virginiana/) Eastern Red-Cedar (Juniperus virginiana) is a severe allergen. Two things are boosting this year’s pollen records across much of the U.S.: 1) higher carbon dioxide concentrations (the atmospheric recording just exceeded 400 parts per million in Hawaii) cause plants to produce more pollen; and 2) Lots of precipitation in late winter and warmer current temperatures set the stage for excess tree pollen.
So what is actually occurring when you react to an allergen? I checked on WebMd and this is what I learned: “First, a person is exposed to an allergen by inhaling it, swallowing it, or getting it on or under their skin. After a person is exposed to the allergen, a series of events create the allergic reaction:
The body starts to produce a specific type of antibody, called IgE, to bind the allergen. The antibodies attach to a form of blood cell called a mast cell. Mast cells can be found in the airways, in the intestines, and elsewhere. The presence of mast cells in the airways and GI tract makes these areas more susceptible to allergen exposure. The allergens bind to the IgE, which is attached to the mast cell. This causes the mast cells to release a variety of chemicals into the blood. Histamine, the main chemical, causes most of the symptoms of an allergic reaction.” Great, just lovely.
There are several competing sites online for pollen forecasting and the requisite allergy http://www.pollen.com/allergy-weather-forecast.asp is one place to go for the latest news on pollen forecasts for the U.S. A link on the Pollen.com website allows one to plug in a zip code and get the pollen history for our area over the past month. Nantucket’s allergy and hay fever readings from April 20 to May 20th are at the top of the chart, hovering between 7.6 to 11.00 with most readings straddling along the 10.00 mark. Pollen.com uses the IMS Health Incorporated techniques for measuring and reporting pollen and provided social media apps and other devices for tracking pollen counts. Their pollen counts are divided into 5 categories: Low (0-2.4), low-medium (2.4-4.8), medium (4.9-7.2), medium high (7.3-9.6) and high (9.7-12). In case you don’t know this (I hadn’t thought of it myself) pollen readings and allergy advice and medical recommendations for allergy sufferers are big business, so you may want to rely on the American Academy of Allergy, Asthma & Immunology who also provides national forecasts and pollen measurements for weeds, trees, mold (not technically a pollen but a spore) and grass using a Nation Allergy Bureau (NAB) scale http://www.aaaai.org/global/nab-pollen-counts/reading-the-charts.aspx retrieved May 19th, 2013). But, the NAB doesn’t have a Massachusetts pollen indexing or counting station.
A pollen count is the measurement of the number of grains of pollen in a cubic meter of air. Air sampling devices are installed around the U.S. to measure pollen and other atmospheric pollutants. As the pollen number increases, people with allergies will have an increase in their allergic reaction. Pollen counts are measured from low, meaning they affect few individuals, to high, meaning symptoms affect most allergy sufferers. Pollen is collected using a rod covered with a sticky substance or with silicon grease that is attached to the roof of a building. For 24 hours, the rotating rod is tested periodically at different times of the day for the amount of pollen adhered to it. Samples are then analyzed microscopically to determine how much pollen is in the air to yield allergy levels. Typically spring yields the highest pollen levels, when plants, grasses, and trees are flowering, particularly in the early mornings. Warm, dry, and windy weather and climates with little or no rain have high pollen levels. Rain or cool weather dramatically drops allergy levels. However, many plants pollinate year round so you could experience allergy symptoms year round.
The primary factor that influences the pollen index is the number of pollen sources, which are flowering plants that produce pollen. Geographic areas with a high level of pollen-producing vegetation will have a higher corresponding pollen level during peak fertilization season. Pollen levels and sources also vary depending on the season.
Many things come into play with forecasting and hindcasting pollen levels, not the least of which is weather conditions. A wet spring with a long period of high photoperiod (aka sunny) days leads to high pollen counts. When it rains, pollen is washed out of the air and we get a brief reprieve. Fortunately for allergy sufferers across the U.S., 2013 will not be as bad as last year, when an unusually warm winter caused the season to start earlier and last longer. Other experts say it is too early to relax though. Adult and pediatric allergy specialist Clifford Bassett, MD, clinical assistant professor of medicine at the New York University School of Medicine and Langone Medical Center believes this year will be quite bad due to a wet winter and warmer spring. He predicts the season will start 14 days earlier and run into October (http://www.rodale.com/2013-allergies retrieved May 19th, 2013). Weather.com provides some excellent resources to help allergy suffers predict and adjust to allergy conditions (http://www.weather.com/health/pollen/forecast/USMA0046 retrieved May 19th, 2013).
For some time, it has been known that allergic conditions tend to cluster in families. Your own risk of developing allergies is related to your parents’ allergy history. If neither parent is allergic, the chance that you will have allergies is about 15%. If one parent is allergic, your risk increases to 30% and if both are allergic, your risk is greater than 60% (http://www.webmd.com/allergies/guide/who-gets-allergies retrieved May 19th, 2013. I am one of the lucky few people with absolutely no allergy issues of any kind. Every other person in my family has a variety of allergies, some quite severe, but I dodged that evolutionary bullet. With a 30% chance coming from one parent with severe allergies and two brothers exhibiting allergy symptoms, I became the lucky third with none. There are a variety of opinions as to how people develop allergies and whether they may be on the rise. Many scientist predict that global warming and climate change will lead to a longer growing season in temperate regions which may double the amount of
There are several ways one can deal with allergies. You can take a variety of antihistamines which dampen allergic responses. Many people swear by the ancient technique of using a neti pot; which is a tiny ceramic pot in which warm water is placed so that you can use it to wash out the inner lining of your nasal passages and clean the tiny hairs called cilia in your nose. The neti pot is also recommended by American Academy of Allergy, Asthma & Immunology (AAAAI) for allergy sufferers. The AAAAI even posted a recipe that allows you to create your own saline solution. You should always use distilled or boiled water when using the neti pot to avoid infection. I don’t like getting water up my nose for any reason, so I’ll be thankful yet again for not having allergies.
Eating honey from local bees is one unproven although enticing method of alleviating allergies. According to Neil Kao, an allergist and station head for the Allergic Disease and Asthma Center, simply eating local honey picked up at a farmer’s market is not going to help with your oak, ragweed or juniper tree allergy. Kao states that the pollen that bees gather from flowers is heavier than the tree and grass pollen that are the main causes of springtime allergy misery (http://abcnews.go.com/Health/Allergies/alternative-allergy-remedies-fact-fiction/story?id=18792233#1 retrieved May 19th, 2013. Acupuncture has been proven to reduce allergy symptoms although the cure is relatively immediate and goes away soon after acupuncture is discontinued. For serious allergies like members of my family dealt with, shots containing small amounts of allergens are given throughout childhood to induce a tolerance to allergens in a process called immune therapy.
Although scientists have not pinned down a cause, it does appear that more Americans are reporting and possibly suffering from allergy symptoms than ever before. About 54 percent of Americans are sensitive to at least one allergy-inducing substance, according to a national survey conducted from 1988 to 1994 by the National Institutes of Health (NIH). That’s about two to five times higher, depending on the allergen, than the rates found by NIH between 1976 and 1980. From 1997 to 2007, the number of children with food allergies rose 18 percent, according to the Centers for Disease Control and Prevention. This can possibly be attributed to better healthcare, more reporting, and more aware parents, but environmental factors like smog and a longer growing season from climate change are increasingly looking like likely causes.
A recent high tech development is using the power of NASA’s remote sensing and weather forecasting ability to track pollen producers regionally and provide more accurate forecast of pollen alerts so that people can make better decisions on outdoor activities. As I write this article, a gentle rain is falling, which means tomorrow will be a good day for outdoor activities. If you do suffer from allergies, try to avoid leaving windows open at night; take a shower right before you go to bed, and take antihistamine remedies before you feel miserable.
The pollen library at http://www.pollenlibrary.com/ gives more detail on specific allergens.
Information on this article was also collected at
http://www.cnn.com/2013/04/30/health/pollen-counts-levels retrieved May 19th, 2013.
http://www.livescience.com/8168-americans-sneeze-allergies-mysteriously-increase.html retrieved May 19th, 2013.