Answers to Pollen Allergies

By Dr. Rajiv Sahay, CIAQP, Director of EDLab

After a long cold winter, many people throughout the world eagerly look forward to the spring season.  Long days, ideal temperatures, gentle breezes and vibrant blossoming flowers attract individuals to enjoy the beauty of this season. While most individuals enjoy time outdoors, many allergy sufferers don’t because the arrival of spring means the return of pollen. These individuals suffer from pollen allergy.  

The onset of uncomfortable allergenic symptoms begins at the start of spring season. Plants bloom during this season and in return release their pollen into the air. Recent reports estimate that more than 67 million Americans suffer from allergy symptoms and at least 10% of the world population suffers from pollen allergy alone. According to US Center for Disease Control and Prevention there are nearly 25 million people suffer from asthma. Pollen allergy may also lead to food allergy. About one-third of people with pollen allergies also may react to certain foods as reported by American College of Allergy, Asthma and Immunology (ACAAI).

Pollen Grains

The male gamete-bearing structures of seed plants are known as “pollen”. They are born in the anthers of flowers; however, in case of non-flowering plants it develops in male cones. Chemically, these biogenic microscopic particles are composed of cellulose, protein, fat, flavonoid and other bio-chemicals. Pollen grains are highly variable in their shape, size, and other physical or biochemical characteristics. With a great deal of morphological variation their size may ranges from 6µm to over 100 µm in diameter. A-biological and biological factors, including environmental parameters, play a significant role in pollen production. A massive quantity of pollen is produced by plants during each pollen season. For example, one Sessile Oak tree (Quercus petraea) produces 654,400,000 pollen grains every year.

Pollen dispersal 

The mechanisms and timing of pollination are of primary importance to determine the potential dispersal of airborne pollen grains. Their counts are variable to the relative density of the plant distribution in any given area. They circulate in nature by wind (anemophilous), insects (entomophilous), animals (zoophilous), water (hydrophilous), etc. Smaller pollen grains (20-55 µm) are more suitable for aerial dispersal in comparison to larger pollen grains (>100 µm). 

Common Plants

Information on the spring season’s common flowering plants with animophilous (airborne) pollen is difficult to obtain; however some of the common plants of this category include, but are not limited to, Acer, Ash, Beech, Cedar, Cotton wood, Cypress, Elm, Grasses, Hickory, Juniper, Maple, Mulberry, Nettle, Oak, Palm, Perennial weeds, Pecon, Pine, Poplar, Sycamore, Walnut, Weeds, Willow, etc.

Pollen and Allergy

Pollen grains are recognized as the most important aeroallergens and are capable of causing a number of allergenic symptoms in humans and animals. Some common allergenic reactions include asthma, allergic shiners (dark circles under the eyes), conjunctivitis, fever, headaches, running and sniffling nose, sneezing, watery eyes, and itchy eyes, nose, and throat, etc. The susceptible individual may develop allergenic symptoms due to inhalation or contact with pollen. In most cases when allergenic pollen is inhaled through the mucous membranes of the nose, a chain reaction occurs that leads the mast cells in these tissues to release histamine. This powerful chemical dilates the many small blood vessels in the nose. Fluids escape through these expanded vessel walls, which causes the nasal passages to swell and results in nasal congestion. Besides histamine, other chemicals are also released. These chemicals are capable of causing itching, irritation and excess mucus production that contributes to the allergenic behavior. Due to narrowing bronchial passages and excess mucus production, asthmatic symptoms like coughing, wheezing, shortness of breathe, etc. appear and if not addressed properly can become a serious respiratory problem and later turn into chronic asthma which may possibly be life threatening. 

Pollen and Indoor Environments

Pollen grains are also indoor allergens. According to an estimate based on EDLab’s sample analysis, 31% of air samples and 24% of surface samples taken indoors, noted positive for pollen grain. The average airborne pollen concentration, within a closed environment, reported over 200 counts/m3 whereas the usual surface-borne density of these grains was estimated approximately 70 cts/cm2. These are significant numbers in terms of air or surface-borne contaminants of the indoor environment and need proper attention.  Indoor environment pollens are mainly brought in from the outdoors; however, occasionally indoor plants may be the contributor.

The type and nature of these pollen grains are highly influenced by the surrounding vegetation, flora and environmental conditions around buildings. There are two-peak pollen seasons identified, early spring and early summer (fall, commonly known as season of weeds), when the pollen concentrations both quantitatively as well as qualitatively recorded highest.

Pollen Management in Indoor Environment 

A study undertaken by the Environmental Diagnostics Laboratory reveals that under natural conditions the typical pollen concentration should not exceed 64 counts/m3 in the air and 17 cts/cm2 on indoor surfaces. Although it is desirable to keep the pollen counts less than 10 counts/m3 in indoor air and 2 cts/cm2 on indoors surfaces from a building hygiene point of view.

A two-fold approach is suggested in order to manage pollen in indoor environments. First, know the existing pollen concentration of indoor environment vs. the outdoor and then identify the potential source. For identifying airborne pollen an Evalu-aire test kit is ideal, whereas surface borne pollen concentration can be evaluated by using the Allergen screen test kit. These test kits are available to purchase through Building Health

Check’s online store, www.indoorairtest.com, or you can call 800-422-7873 ext. 404 to speak with someone directly about these products.

Information on the surrounding flora, pollen forecast, and seasonality may be helpful for understanding a pollen source. Routine maintenance of your HVAC system before and after the pollen season also serves to minimize pollen source distribution in buildings.

Managing Pollen Allergies

Prevention and clinical management can minimize risk of pollen allergy.

Prevention:

1. Watch local pollen forecast frequently. When suggested counts are higher spend more time indoor and avoid outdoors.
2. Prevent the entry of pollen indoors by closing doors and windows.  If the building depends on a mechanical filtration system, install the proper filter to avoid the circulation of pollen in the indoor air.
3.  Remove your shoes outside before entering your home.
4. Periodical housekeeping to maintain a clean indoor environment.
5. Avoid taking trips outside during the morning hours. If it is necessary, wear sunglasses to avoid the eye irritation that might cause due to pollen allergy.
6. Plan your vacation to a place where pollen counts are much lower (i.e. a beach environment, etc.)

Clinical management:

There are a number of effective prescriptions or over-the-counter medications available to allergy sufferers such as antihistamines, corticosteroids, and cromolyn sodium, etc.  This medication should be used in consultation with a qualified physician. Immunotherapy (commonly called allergy shots) is other option for the clinical management of allergies. Once the target/potential allergy-causing pollen is identified, a small-diluted dosage of the antigen is given to the patient to increase the patient's tolerance to the particular pollen to which he or she is allergic.

About Pure Air Control Services:

Founded in 1984 by Alan Wozniak, President/CEO in what began as a small mechanical contracting business has grown into an award winning, industry leading indoor air quality (IAQ) service company serving many fortune 500 corporations, school boards, county, city, state and federal governments and consumers across the US.  The firm has serviced over 600 million square feet of indoor environments in over 10,000 facilities. 

Pure Air’s nationally performed services include: Building Sciences Evaluation; Building Health Check; an AIHA accredited Environmental Microbiology Laboratory; Environmental Project Management; and Duct Cleaning & Mold Remediation Services, among other indoor environmental services. The company’s expanding client roster includes the General Services Administration (GSA); Federal Aviation Administration (FAA), Allstate Insurance; Carrier Air Conditioning; Naval Air Warfare Center, Orlando; and Naval Air Station - King's Bay, Georgia, and many other Fortune 500 companies, school boards, and city, state, and county governments, making Pure Air a reliable industry leader.

For more information, visit the company’s web site at www.EDLab.org or contact Dr. Rajiv Sahay or Alan Wozniak at 1-800-422-PURE (7873) ext 301 or 802.