Understanding Mold Exposure: The Most Impacted Cities and States

Mold is a common issue in many households and can have significant health implications, especially for those with allergies or respiratory conditions. Certain cities and states across the United States are more impacted by mold due to various environmental factors. Here's a closer look at the regions where mold is most prevalent and the conditions that contribute to its growth.

The Prevalence of Mold in the United States

Mold thrives in environments that provide moisture, warmth, and a food source. This means that virtually any state or city could be susceptible to mold growth. However, some regions experience higher concentrations of mold due to specific climatic conditions and other contributing factors.

Top States and Cities Impacted by Mold

According to a study by Quest Diagnostics, the states of California, Ohio, and Texas have the highest number of cities ranked among the top 20 worst for mold allergies. This indicates a higher prevalence of mold exposure in these areas, which can be particularly challenging for individuals with mold sensitivities.

California's Mold Challenge

California, with its diverse climate, has four cities in the top 20 worst cities for mold allergy sufferers. The state's combination of coastal humidity and inland aridity creates varied environments where mold can thrive.

Ohio and Texas: High Mold Sensitization

Ohio and Texas each have two cities in the top 20, with Dallas, Texas, leading the list with 21% of allergy patients showing sensitization to mold. These states have regions with high humidity levels and significant rainfall, contributing to the mold issue.

The Southwestern United States: A Mold Hotspot

The southwestern region of the United States is identified as particularly problematic for mold allergy sufferers. This area includes four of the top five worst cities for mold sensitization, with Riverside-San Bernardino and Phoenix following closely behind Dallas.

Cities with the Highest Mold Sensitization Rates

The cities with the highest percentages of allergy patients showing sensitization to mold include:

1. Dallas, Texas—21%
2. Riverside-San Bernardino, California—20%
3. Phoenix, Arizona—19%
4. Los Angeles, California—17%
5. Chicago, Illinois—17%
6. Minneapolis-St. Paul, Minnesota—16%
7. Saint Louis, Missouri—16%
8. Denver, Colorado—16%
9. Kansas City, Missouri—16%
10. San Antonio, Texas—15%

Other Notable States for Mold Prevalence

States such as Florida, Oklahoma, South Carolina, Nevada, Arizona, South Dakota, Tennessee, and Kansas also experience high mold prevalence. Factors like high humidity, significant annual precipitation, and water damage from natural disasters make these states more susceptible to mold growth.

Ideal Conditions for Mold Growth

Mold spores are everywhere, but they require specific conditions to grow into a new colony. These conditions include:

• Presence of Mold Spores: Mold spores are microscopic and ubiquitous, but they become a problem when they land in an ideal environment.
• Ideal Temperatures: Mold prefers temperatures between 50 to 70 degrees Fahrenheit but can survive in a wider range.
• Nutrients: Mold can feed on any organic matter, including wood, paper, and organic fibers.
• Water: Moisture is the final requirement for mold growth. Without water, mold cannot survive.

Protecting Your Home from Mold

To mitigate the risk of mold in your home, consider using a dehumidifier to control moisture levels, especially if you live in a high-risk region. An air purifier for mold can also help reduce airborne mold spores, contributing to a healthier indoor environment.

For a  home inspection checklist and more information on identifying and addressing mold in your home, refer to our free MoldCo Home & Health Guide. This resource can help you spot the signs of potential mold and take the necessary steps to protect your home and health.