Getting outdoors is good for one’s health, but a study suggests that letting the sunlight in is beneficial too. University of Oregon researchers found that exposing indoor rooms to sunlight kills germs. Researchers looked at the microbes found in dust in rooms that were dark, exposed to ultraviolet light or subjected to sunlight through glass, which filters out most UV rays. They found that illuminating the rooms cut down the levels of viable bacteria by about half. ¹

Most Americans spend about 90 percent of their time inside.² The air they breathe behind closed windows and doors can be up to five times more hazardous to their health than outdoor air, reports the Washington Times.³ One indoor air pollutant includes dust, which accumulates microbes, especially in dark, moist rooms. These hazards can contribute to asthma, lung infections, and other respiratory issues.

Bacteria is Bad for Cough and Congestion

The lungs bring oxygen into the body and release carbon dioxide. They also have a defense mechanism to protect themselves against dust. The nose and airways are partly responsible for filtering out some dust before it reaches the lungs. However, when people breathe in large amounts of dust, the body reacts by producing more mucus to expel it. This can lead to chronic cough or congestion.⁴

Dust can contain a wide variety of substances, including bacteria and fungi. Serious diseases can be caused by breathing in dust that is tainted with certain microbes. Dust mites prefer warm, humid locations and die when humidity levels fall below 50 percent. People with a dust allergy may feel worse after cleaning their homes.⁵

Dust can also exacerbate asthma, but individuals don’t have to have asthma to be triggered by dust and other irritants. Allergic rhinitis can cause similar symptoms as asthma in people who aren’t directly allergic to dust.

Dampness, mold, and even bacteria from shed human skin can cause chronic lung disease.⁶ Household irritants, such as dust, chemicals, and germs, can exacerbate COPD, which is the fifth primary cause of death around the world.⁷ Allergic bronchitis may also be aggravated by dust and bacteria. The aforementioned study found that rooms that were lit naturally had fewer species of the certain types of bacteria that are found in dust.

Those who have irritated airways from a chronic respiratory issue may be more susceptible to bacteria. This can lead to pneumonia, sinus infections, and bronchitis, according to WebMD.⁸ This can become a vicious cycle if someone is constantly coughing because of poor indoor air quality. Measures can be taken to improve immunity and reduce symptoms, but people with respiratory issues should also look into environmental factors.

Always Have Naturally Lit Rooms

In the 19^th century, Florence Nightingale introduced an environmental theory that focused on the health professional’s responsibility for balancing the external atmosphere to help combat disease. One aspect of this involved exposing patients to natural light. Many hospitals built thereafter were designed with this theory in mind.⁹

The same concept applies to the home. Temperature, humidity, and ultraviolet light are involved in the survival of airborne pathogens. High temperatures can inactivate viruses. When it comes to humidity, different types of bacteria prefer distinct moisture levels.

Residents can adjust the thermostat or invest in dehumidifiers to balance out temperature and humidity levels. However, increasing the amount of natural light might be just as beneficial. Sunlight has been found to decrease the number of microbes in indoor dust by 50 percent.

Letting sunlight fill the indoor space is even more important during cold and flu season. When trapped inside, airborne viruses can cause direct illness and trigger other diseases, like asthma, which are mediated by the immune system, according to researchers. This problem is worse for people who live in close quarters with others.¹⁰

Plus, respiratory illnesses tend to proliferate during the colder months of the year, when there are fewer hours of daylight. It’s no surprise, therefore, that people are more likely to get sick if they stay inside and keep the windows closed.

According to Robert Glatter, M.D., who was quoted in Elite Daily, using lamps that emit natural light can be used in the corners of the home that aren’t exposed to sunlight. Opening the blinds during the daylight hours might be more effective, though.¹¹

Other Treatments for Cough and Congestion

Those who tend to have a lingering cough or can’t shake a cold might consider exposing their indoor environment to natural sunlight for its bacteria-fighting benefits. They can also try to boost their immune system using natural remedies. According to Everyday Health, some of these include the following.

1. Getting enough high-quality sleep
2. Avoiding smoke
3. Limiting alcohol consumption
4. Eating a well-rounded diet
5. Consuming probiotics
6. Increasing vitamin D levels
7. Eating raw garlic
8. Taking immuno-supportive herbs¹²

Up to three-quarters of Americans don’t drink enough water, according to Medical Daily.¹³ Boosting fluid intake when someone has a respiratory ailment can thin their mucus and replace fluid that they’ve lost through rapid breathing. Drinking warm beverages can bring immediate relief for symptoms such as congestion, cough, and sneezing, say researchers.¹⁴

Individuals can treat the symptoms of many respiratory ailments using a variety of over-the-counter medications, including the following.

1. Antihistamines
2. Decongestants
3. Expectorants
4. Cough suppressants¹⁵

These medications won’t cure the condition or reduce the triggers of cough and congestion. However, they could provide a quick fix to help people feel better temporarily while they open their blinds and wait for the sunlight to stream in.