Homeowners must beware of areas of moisture and heat that can harbor a fast-growing, possibly toxic fungus. (bigstock)

Summertime traditionally brings family trips, school vacations, as well as plenty of hot uncomfortable weather. Those sunny days, however, often come with high humidity and afternoon thundershowers — ideal conditions for annoying and potentially toxic mold.

It’s a pervasive menace that is poised each summer to grow and thrive in your house. Left unattended, fast-growing mold can cause damage that will cost in the thousands of dollars to eradicate or, worse, pose a dangerous threat to the health of your entire family.

“No one knows how many homes have mold behind the walls, but the best estimate is about 70 percent,” said Richard E. Gots, a doctor and founder of the International Center for Toxicology and Medicine, a biomedical consulting firm.

Gots’s estimate refers to mold that is at an “elevated level” and therefore should be addressed if the conditions exist for the mold to take hold and grow.

The Environmental Protection Agency sets levels for acceptable radon levels as well as a threshold for lead in the house or water supply, and states regulate termite inspections and control compliance. Yet there are no federal or state regulations that dictate a safe level of mold for a residential property.

D.C. Council member Mary M. Cheh (D-Ward 3) has been campaigning for several years to pass legislation that would require residential property owners, including landlords, to disclose the presence of mold in their apartment, condo or house. This legislation is still pending.

According to the District’s housing code, the Department of Consumer Regulatory Affairs (DCRA) inspectors cannot cite a homeowner for mold because the city considers mold to be “an environmental problem,” rather than a housing or safety issue. Mold, of course, is notoriously difficult to detect, and what may look like dangerous mold can only be legitimately determined under a microscope by a competent inspector or lab. Additionally, most homeowner insurance policies will not cover damage from mold — they consider it a “preventable” condition.

In reality, mold is a fungus that can grow anywhere moisture is present. Mold spores thrive in warm temperatures (77 to 86 degree Fahrenheit) and wherever there are damp conditions. Mold spores are in the air we breathe, and they can grow on any surface. In a house, mold can be found in ceilings and walls, under sinks, in drywall, hidden behind wallpaper or baseboards, in the ductwork or even on furniture and clothes. It can also grow outdoors under wood piles or mulch, gutters or abandoned trash.

Mold in a house can lay dormant until it gets the needed heat and humidity to grow and multiply. Additionally, it needs a food source, such as dust, dirt or some other organic debris.

While not everyone will react to this growth in the same way, those sensitive to allergic or toxic mold can develop alarming symptoms upon merely entering a contaminated room. The result can be a serious — even life-threatening — illness if not treated in time.

If you suspect that you’ve been exposed to mold — or begin to experience dizziness, fatigue, nausea, shortness of breath or other symptoms of illness — contact a mold specialist and have your property inspected as soon as possible. Licensed professionals will test the air quality of your house and take samples of the visual mold, which will be sent to a qualified lab for evaluation.

The EPA provides helpful information in its publication “A Brief Guide to Mold, Moisture, and Your Home” at www.epa.gov/mold/moldguide.html . And the Centers for Disease Control and Prevention focuses on the health hazards of mold exposure and provides recommendations for removing mold exposure at www.cdc.gov/mold/dampness_facts.htm#note .

In addition to the traditional methods for eradicating mold (such as using chemicals or chlorine bleach and physically removing infected surfaces), there is a new, enzyme-based alternative. Previously used as a protective spray for fruits and vegetables, it is now available for home use.

Jenn Sherwood, manager of Green Home Solutions of Maryland, says that the enzyme spray is a cost-effective, time-saving and environmentally responsible way for homeowners to eradicate mold. The process uses a “fogger,” which emits a fine spray that is able to penetrate most porous surfaces (such as drywall) or even non-visible areas — behind walls or inside insulation. This method of eradicating mold often eliminates the need to remove and replace the existing material.

The EPA regards this spray as nontoxic to humans or pets and harmless to both surfaces and belongings in the home. The enzyme works by creating a bond with the mold spore, and then breaking it down from the inside. As a result, the mold is chemically altered into a particle that is no longer allergenic, toxigenic, or able to reproduce other spores. This treatment can cost from one-third to one-tenth less than the cost of traditional methods.

Given that your insurance company may not cover mold damage, it’s important to take immediate action.

Here are three easy steps to help prevent mold when you go on vacation:

●Check for areas where water could accumulate — such as around windows, doors, bathroom leaks, kitchen sinks and washing machines.

●Clean surfaces of oil, soap, dust and dirt. Those materials are a feeding ground for mold when moisture is present.

●Set the temperature inside the house in the low 70s, if possible. If you suspect humidity, set a dehumidifier to keep the moisture level below 60 percent. In your closet, place a hanging moisture absorber (such as Damp Rid) that will trap excess humidity and eliminate musty odors.

Sandy Gadow, a freelance writer and author of “The Complete Guide to Your Real Estate Closing,” is a former title officer and licensed real estate agent with more than 20 years of experience. Gadow will answer readers’ questions in the future columns. Contact her at sandragadow1@gmail.com.