Allergens and Pollen

 

Climate change will potentially lead to both higher pollen concentrations and longer pollen seasons, causing more people to suffer more health effects from pollen and other allergens.

Pollen is an airborne allergen that can affect our health. Pollen grains are tiny “seeds” dispersed from flowering plants, trees, grass, and weeds. The amount and type of pollen in the air depends on the season and geographic region. Though pollen counts are typically higher during the warmer seasons, some plants pollinate year-round.

Climate change will potentially lead to shifts in precipitation patterns, more frost-free days, warmer seasonal air temperatures, and more carbon dioxide (CO2) in the atmosphere. These changes can affect:

When the pollen season starts and ends and how long it lasts each year,

How much pollen plants create and how much is in the air,

How pollen affects our health (the “allergenicity” of pollen),

How much pollen we’re exposed to, and

Our risk of experiencing allergy symptoms.

Pollen exposure can trigger various allergic reactions, including symptoms of hay fever. Hay fever, also known as allergic rhinitis, occurs when allergens like pollen enter your body and your immune system mistakenly identifies them as a threat. If you have allergic rhinitis, your body then responds to the allergen by releasing chemicals that can cause symptoms in the nose. Symptoms of allergic rhinitis can occur during certain seasons or year-round, depending on the allergen.Symptoms from allergic rhinitis include sneezing, runny nose, and congestion.

 

Pollen exposure can also trigger symptoms of allergic conjunctivitis. Allergic conjunctivitis is the inflammation of the lining of the eye (conjunctiva) due to exposure to allergens like those in pollen. Allergic conjunctivitis is found in up to 30% of the general population and as many as 7 out of 10 of patients with allergic rhinitis. Symptoms from allergic conjunctivitis include red, watery, or itchy eyes.

People with respiratory illnesses like asthma may be more sensitive to pollen. Exposure to pollen has been linked to asthma attacks and increases in hospital admissions for respiratory illness. Medical costs linked with pollen exceed $3 billion every year, with nearly half of those costs being linked to prescription medicine. Higher pollen concentrations and longer pollen seasons can also make you more sensitive to allergens. This can trigger asthma episodes in individuals with asthma and diminish productive work and school days.

Extreme rainfall and rising temperatures also can contribute to indoor air quality problems. For example, they can cause the growth of mold indoors, which may lead to worsened respiratory conditions for people with asthma and/or mold allergies and heightened challenges in maintaining adequate asthma control.

 

Pollen and Your Health

 

Parthenium is one of the highest pollen polluters. One plant can produce a billion grains of pollen each season. Parthenium is the primary contributor to fall season allergies.

Ragweed is one of the highest pollen polluters. One plant can produce a billion grains of pollen each season. Parthenium is the primary contributor to fall season allergies.

 

What is pollen?

Pollen is the grains or tiny seeds of flowering plants, trees, and grasses. These seeds can be carried on the wind and can cause various symptoms, or none at all, in individuals who are exposed to them.

What health problems can pollen cause?

For people with hay fever, also known as “allergic rhinitis,” breathing in pollen can cause sneezing, congestion, and a runny nose. Pollen exposure can also result in “allergic conjunctivitis” in some individuals, causing red, watery, or itchy eyes.

Pollen exposure can also cause asthma attacks in people who have asthma and for whom pollen is an asthma trigger.

How can I protect myself against pollen?

If you are allergic to pollen or if you have asthma you can take steps to protect yourself:

Check pollen forecasts on local news and online sources and plan to spend less time outdoors when pollen levels will be high.

Take your allergy and/or asthma medications as prescribed by your health care provider.

Don’t touch your eyes while you are outside, and wash your hands when you go back inside (before you touch your eyes).

Shower after being outside to remove pollen from your skin and hair.

Change your clothes after being outdoors.

Keep windows closed during pollen season.

Use high-efficiency filters in your home’s heating, ventilation, and air conditioning (HVAC) system. Make sure your HVAC system can use high-efficiency filters and that they don’t violate the system’s warranty.

 

How is climate change affecting pollen levels?

Our changing climate has caused shifts in precipitation patterns, more frost-free days, warmer seasonal air temperatures, and more carbon dioxide (CO2) in the atmosphere. These changes can affect:

When the pollen season starts and ends and how long it lasts each year,

How much pollen plants create and how much is in the air, and

How pollen affects human health.

Some of these changes in pollen due to climate change could have major impacts on human health such as increasing individuals’ exposure to pollen and their risk of having allergy and/or asthma symptoms.