Mold in Our Environment: Facts and Information for the Cal Poly Community

Like pollen and dust, mold is a natural part of our environment, mold spores are present everywhere in our daily environment, both indoors and out. On the Central Coast, people typically inhale 10,000 to 20,000 mold spores each day during normal activities. During peak seasonal periods, this number can increase to 50,000 or more spores per day.

Local Environmental Factors

San Luis Obispo's coastal climate can be different from what many students are used to:

  • Marine layer moisture can contribute to higher humidity levels
  • Local vegetation and seasonal changes create unique allergen patterns
  • Coastal air can carry different types of spores than inland areas
  • San Luis Obispo's coastal environment contains different allergens than many other regions
  • Your body may need time to adapt to local plants, pollens, and seasonal patterns
  • Moving between different climate zones can affect how you feel
Mold spores are common allergens that can trigger cold-like symptoms in sensitive people, including stuffy or runny nose, itchy watery eyes, sneezing, and throat irritation - similar to reactions from pollen, dust, or pet dander. When students move to different climates, they might notice new symptoms, but it's also normal to see more illness initially as they transition from home to shared dorm spaces where germs spread more easily, especially when immune responses may be weakened by the added stress of that transition.

Adapting to Campus Living

Living Environment Changes:

  • Moving from a private living space to a residence hall means sharing space with many others
  • This naturally increases exposure to common viruses and bacteria
  • Your immune system needs time to adjust to a new community living environment

Lifestyle Factors to Consider:

  • Campus life often involves different sleep patterns than you're used to
  • Meal timing and food choices may vary from your previous routine
  • Academic demands can affect stress levels and immune response
  • Your daily schedule and habits are likely quite different from home

While certain types of mold can be a health concern for certain individuals, it's important to understand the facts about mold and distinguish between common misconceptions and health risks.

Who is at Risk?

The CDC identifies specific groups who may be sensitive to mold exposure:

  • People with diagnosed, severe, mold allergies
  • Individuals with severely compromised immune systems
  • Those with chronic respiratory conditions

For most healthy individuals, brief exposure to common household mold does not pose any health risks.

Facts About Mold from the CDC and EPA

  • The term "black mold" has no scientific meaning, as many molds can appear dark
  • While certain molds can produce toxins, the presence of dark-colored mold does not automatically indicate a specific type of mold or signify a health hazard
  • Mold growth requires moisture - controlling humidity is key to preventing mold
  • Hidden mold is rare and typically only occurs with ongoing water damage

If hidden mold is present, it is typically accompanied by clear signs:

  • Visible water damage
  • Distinct and persistent musty odors
  • Warped or discolored building materials

Common Sources of Mold in Dorm Rooms

The most common sources of mold in residence halls typically come from everyday items, rather than building materials:

  • Food left in trash cans, especially in warm weather
  • Forgotten leftovers in containers
  • Coffee grounds and tea bags in trash
  • Dirty dishes left for extended periods
  • Wet paper products in trash
  • Damp towels, clothes, etc.

These organic materials can develop mold within 24-48 hours, creating unpleasant odors and potentially triggering allergy symptoms.

Preventing Mold Growth in Your Living Space

Maintain good ventilation:

  • Use bathroom fans during and after showers
  • Keep doors and windows open, when possible, to promote air circulation
  • Don't block air vents or returns

Control humidity:

  • Keep living spaces clean and dry
  • Don't leave wet items (towels, gym clothes, wetsuits) in enclosed spaces
  • Use dehumidifiers if provided
  • Report any leaks or water intrusion immediately

Practice good housekeeping:

  • Empty trash regularly, especially when containing food waste
  • Don't leave perishable items or leftovers in open containers
  • Clean spills and crumbs promptly

What to Do If You See Mold

Common mold situations:

  • Small amounts of mold on windowsills after rain or condensation can be safely cleaned with household cleaners and a paper towel
  • Bathroom mold around caulking or grout is addressed with regular cleaning
  • Mold on shower curtains can be handled by washing or replacing the curtain

If you notice mold:

  1. Report it through the campus maintenance portal
  2. Clean small areas with soap and water
  3. Address any moisture sources immediately
  4. Keep the area well-ventilated
  5. Mold growing on walls, carpets, or other unexpected places should always be reported, as this may indicate an underlying moisture problem.

When to Seek Help

Contact Student Health Services if you:

  • Have a diagnosed mold allergy or immune condition
  • Experience new respiratory symptoms that persist

Resources and Additional Information