Indoor or Outdoor, Allergy Complaints Spike With the Season

Apr. 2, 2019

Shaundree Davis, Senior Program Manager for Industrial Hygiene at Princeton EHS, has seen the phenomenon before.

In the first half of April, pollen production begins to go up rapidly in Central New Jersey, and calls to her office increase. 

“Spring sees a general increase in reports of allergic reactions and discomfort, even in situations you might not expect, such as indoors,” she says.

The reason is not that sources of indoor allergic reactions, such as mold or dust mites, necessarily increase in the spring. The culprit is the same as if you were outside walking in a park: pollen. 

Pollen, designed by nature to spread easily for the purposes of fertilization, hitches a ride on clothing, hair and pets, and travels through open doors and windows (even those with screens).  

In fact, pollen counts can sometimes be higher indoors than outdoors during spring allergy season. How is this possible? Pollen brought indoors becomes trapped inside, and the amount increases as more is added. Rather than being blown around or diluted by huge outdoor spaces, indoor pollen tends to stay put in carpets, fabrics and surfaces—and can be kicked up by dusting or vacuuming. For this reason, pollen can linger indoors long after outdoor allergy season has officially passed. 

Preventing Pollen Indoors

There are a few steps you can take to reduce buildup of pollen indoors. Most are best applied at home but some are also applicable to the office.

  • Close windows and use air conditioning. (Residents of older campus buildings with less efficient AC may wish to open windows for optimal air circulation.) 
  • Leave your coat and, if possible, shoes at the door. Removing shoes inside and keeping coats on a rack or in a foyer is a good way to prevent the buildup and spread of pollen throughout indoor spaces.
  • Remove dust with a damp rag rather than dry dusting.
  • Empty vacuum cleaners outdoors. 
  • Take a shower before bed to prevent pollen buildup on pillows and sheets. 
  • Change clothes when returning home and do laundry frequently. 
  • Clean pets when they come inside with a damp rag. 

During allergy season, keep track of pollen counts using the American Academy of Allergy Asthma & Immunology website: Click on a region to see the allergy forecast in your area. This is a great resource for tracking and preventing allergies, and also helps to clarify whether indoor allergy problems are due to pollen counts, or something else. 

These measures should go a long way to preventing a serious problem with seasonal allergies, short of being engulfed by a pollen bomb.