Chapter 40: Section 9.4—SARS-CoV-2 (COVID-19) - Environmental Health Sourcebook, 6th Ed. (2023)

Section 9.4 | SARS-CoV-2 (COVID-19)

This section contains text excerpted from the following sources: Text in this section begins with excerpts from “Coronavirus Disease 2019 (COVID-19),” Centers for Disease Control and Prevention (CDC), September 20, 2021; Text beginning with the heading “Watch for Symptoms” is excerpted from “Symptoms of COVID-19,” Centers for Disease Control and Prevention (CDC), February 22, 2021; Text under the heading “Protect Yourself” is excerpted from “How to Protect Yourself & Others,” Centers for Disease Control and Prevention (CDC), August 13, 2021; Text under the heading “Research on COVID-19” is excerpted from “COVID-19 Research,” U.S. Environmental Protection Agency (EPA), April 29, 2021.

Coronavirus disease (COVID-19) is a respiratory disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a new coronavirus discovered in 2019. The virus is thought to spread mainly from person to person through respiratory droplets produced when an infected person coughs, sneezes, or talks. Some people who are infected may not have symptoms. For people who have symptoms, illness can range from mild-to-severe. Adults 65 years and older and people of any age with underlying medical conditions are at higher risk for severe illness. People 12 years and older should get COVID-19 vaccines to prevent getting and spreading the illness.

Prevention Tips

•Get a COVID-19 vaccine if you are 12 or older. COVID-19 vaccines are safe, effective, and free!

•Wash your hands with soap and water for at least 20 seconds. If soap and water are not available, use a hand sanitizer that contains at least 60 percent alcohol.

•Avoid close contact with people outside your home. Stay at least 6 feet (about 2 arms’ length) from others.

•Wear a mask in public, even if you do not feel sick. The make cover will help protect others in case you are infected.

•Cover your coughs and sneezes with a tissue or the inside of your elbow. Throw used tissues in the trash and then wash your hands with soap and water for at least 20 seconds.

•Clean and disinfect frequently touched surfaces daily. This includes tables, doorknobs, light switches, countertops, handles, desks, phones, keyboards, toilets, faucets, and sinks.

•Stay home if you have symptoms such as fever, cough, shortness of breath.

•Seek emergency medical care if you develop severe symptoms, such as trouble breathing, chest pain, new confusion, inability to wake or stay awake, or pale, gray, or blue-colored skin, lips, or nail beds, depending on skin tone.

Watch for Symptoms

People with COVID-19 have had a wide range of symptoms reported – ranging from mild symptoms to severe illness. Symptoms may appear 2–14 days after exposure to the virus. Anyone can have mild to severe symptoms.

People with these symptoms may have COVID-19:

•Fever or chills

•Cough

•Shortness of breath or difficulty breathing

•Fatigue

•Muscle or body aches

•Headache

•New loss of taste or smell

•Sore throat

•Congestion or runny nose

•Nausea or vomiting

•Diarrhea

This list does not include all possible symptoms.

When to Seek Emergency Medical Attention

Look for emergency warning signs* for COVID-19. If someone is showing any of these signs, seek emergency medical care immediately:

•Trouble breathing

•Persistent pain or pressure in the chest

•New confusion

•Inability to wake or stay awake

•Pale, gray, or blue-colored skin, lips, or nail beds, depending on skin tone

*This list is not all possible symptoms. Please call your medical provider for any other symptoms that are severe or concerning to you.

Call 911 or call ahead to your local emergency facility: Notify the operator that you are seeking care for someone who has or may have COVID-19.

Protect Yourself

Get Vaccinated

•Authorized COVID-19 vaccines can help protect you from COVID-19.

•You should get a COVID-19 vaccine as soon as you can.

•Once you are fully vaccinated, you may be able to start doing some things that you had stopped doing because of the pandemic.

Wear a Mask

•Everyone 2 years or older who is not fully vaccinated should wear a mask in indoor public places.

•In general, you do not need to wear a mask in outdoor settings.

•In areas with high numbers of COVID-19 cases, consider wearing a mask in crowded outdoor settings and for activities with close contact with others who are not fully vaccinated.

•People who have a condition or are taking medications that weaken their immune system may not be fully protected even if they are fully vaccinated. They should continue to take all precautions recommended for unvaccinated people, including wearing a well-fitted mask, until advised otherwise by their healthcare provider.

•If you are fully vaccinated, to maximize protection and prevent possibly spreading COVID-19 to others, wear a mask indoors in public if you are in an area of substantial or high transmission.

Wearing a mask over your nose and mouth is required on planes, buses, trains, and other forms of public transportation traveling into, within, or out of the United States and while indoors at U.S. transportation hubs such as airports and stations. Travelers are not required to wear a mask in outdoor areas of a conveyance (such as on open deck areas of a ferry or the uncovered top deck of a bus).

Stay Six Feet Away from Others

•Inside your home

•Avoid close contact with people who are sick.

•If possible, maintain six feet between the person who is sick and other household members.

•Outside your home

•Remember that some people without symptoms may be able to spread virus.

•Stay at least six feet (about 2 arm lengths) from other people, especially if you are at higher risk of getting very sick.

Avoid Crowds and Poorly Ventilated Spaces

•Being in crowded places like restaurants, bars, fitness centers, or movie theaters puts you at higher risk for COVID-19.

•Avoid indoor spaces that do not offer fresh air from the outdoors as much as possible.

•If indoors, bring in fresh air by opening windows and doors, if possible.

Test to Prevent Spread to Others

•Testing can give you information about your risk of spreading COVID-19.

•You can choose from many different types of tests.

•Regardless of the test type you select, a positive test result means that you have an infection and should isolate and inform your close contacts to avoid spreading disease to others.

•Over-the-counter self-tests can be used at home or anywhere, are easy to use, and produce rapid results. Anyone can use self-tests, regardless of vaccination status or whether they have symptoms or not.

•Consider using a self-test before joining indoor gatherings with others who are not in your household.

•A positive self-test result means that you have an infection and should avoid indoor gatherings to reduce the risk of spreading disease to someone else.

•A negative self-test result means that you may not have an infection. Repeating the test with at least 24 hours between tests will increase the confidence that you are not infected.

•Ask your healthcare provider if you need help interpreting your test results.

Wash Your Hands Often

•Wash your hands often with soap and water for at least 20 seconds especially after you have been in a public place, or after blowing your nose, coughing, or sneezing.

•It is especially important to wash your hands:

•Before eating or preparing food

•Before touching your face

•After using the restroom

•After leaving a public place

•After blowing your nose, coughing, or sneezing

•After handling your mask

•After changing a diaper

•After caring for someone sick

•After touching animals or pets

•If soap and water are not readily available, use a hand sanitizer that contains at least 60 percent alcohol. Cover all surfaces of your hands and rub them together until they feel dry.

•Avoid touching your eyes, nose, and mouth with unwashed hands.

Cover Coughs and Sneezes

•If you are wearing a mask: You can?cough or sneeze into your mask. Put on a new, clean mask as soon as possible and wash your hands.

•If you are not wearing a mask:

•Always cover your mouth and nose with a tissue when you cough or sneeze, or use the inside of your elbow and do not spit.

•Throw used tissues in the trash.

•Immediately wash your hands with soap and water for at least 20 seconds. If soap and water are not readily available, clean your hands with a hand sanitizer that contains at least 60 percent alcohol.

Clean and Disinfect

•Clean high touch surfaces daily. This includes tables, doorknobs, light switches, countertops, handles, desks, phones, keyboards, toilets, faucets, and sinks.

•If someone is sick or has tested positive for COVID-19, disinfect frequently touched surfaces.

•Use a household disinfectant product from EPA’s List N: Disinfectants for Coronavirus (COVID-19) according to manufacturer’s labeled directions.

•If surfaces are dirty, clean them using detergent or soap and water prior to disinfection.

Monitor Your Health Daily

•Be alert for symptoms:

•Watch for fever, cough, shortness of breath, or other symptoms of COVID-19.

•Take your temperature if symptoms develop.

•Do not take your temperature within 30 minutes of exercising or after taking medications that could lower your temperature, such as acetaminophen.

•Follow the CDC guidance if symptoms develop.

•Monitoring symptoms is especially important if you are running errands, going into the office or workplace, and in settings where it may be difficult to keep a physical distance of six feet.

Difference between COVID-19 and Flu

Influenza (Flu) and COVID-19 are both contagious respiratory illnesses, but they are caused by different viruses. COVID-19 is caused by infection with a new coronavirus (called “SARS-CoV-2”), and flu is caused by infection with influenza viruses.

COVID-19 seems to spread more easily than flu and causes more serious illnesses in some people. It can also take longer before people show symptoms and people can be contagious for longer.

Because some of the symptoms of flu and COVID-19 are similar, it may be hard to tell the difference between them based on symptoms alone, and testing may be needed to help confirm a diagnosis.

While more is learned every day about COVID-19 and the virus that causes it, there is still a lot that is unknown.

Research on COVID-19

The U.S. Environmental Protection Agency’s (EPA) researchers are building on an expansive body of world-class research by applying knowledge to reduce the risk of exposure to SARS-CoV-2, the virus that causes COVID-19.

Research on COVID-19 in the Air

Common modes of transmission of COVID-19 include aerosols or respiratory droplets that are produced when a person coughs, sneezes, sings or talks, particularly in indoor environments with limited ventilation. Aerosols are very tiny particles that linger in the air and move with air currents like smoke or dust. Respiratory droplets are larger and fall, landing on surfaces where they can linger hours to days.

The focus of this research was an “open office” such as a cubicle work environment where there is concern about how aerosols from an infected person, though likely asymptomatic, might affect other workers in other locations in an office. This research will first determine potential levels of exposure and then look at practical office modifications that might reduce exposure to the virus.

Researchers are also looking at technologies that are safe to operate in spaces where there will be people, like offices, subways, restaurants, etc., to reduce the amount of SARS-CoV-2 in the air. These technologies include devices and products like ultraviolet C (UV-C) devices, chemical-based devices, and physical removal devices like filters.

Research on COVID-19 on Surfaces

Respiratory droplets, which are larger, and fall quickly, can still be a mode of transmission for SARS-CoV-2, the virus that causes COVID-19. First, researchers had to develop a way to quickly detect live virus in surface samples because current testing takes a few days to get results, which would be too late to worry about surface contamination. Researchers developed a rapid analytical method so that they could understand potential surface transmission in a short time.

Areas that are frequently touched by many different people can pose a public-health risk during the pandemic, so researchers evaluated commercially available antimicrobial products for potential long-lasting effectiveness against the virus. Currently, EPA-registered products with long-lasting effectiveness claims are limited to those that control odor-causing bacteria on hard, nonporous surfaces; there are no EPA registered products with public-health claims that provide long-lasting (e.g., weeks to months) disinfection. The benefits of having a longer-lasting antimicrobial product are important, especially when cleaning and disinfecting a surface or object cannot be accomplished every time someone new touches it.

In addition, ways to apply disinfectants to many different, large surface areas quickly and effectively were needed to reduce the risk of exposure to the virus. Researchers evaluated electrostatic sprayers and foggers to rapidly apply disinfectants over large, complex surface areas.

At the request of some of the countries largest transit agencies, the EPA researchers also studied whether UV-C could inactivate the SARS-CoV-2 virus on subways and buses. This results from this research are useful for business owners, school administrators, and others.

Overall, this research will help decision makers determine the best ways to help reduce the risk of exposure to COVID-19 from potential surface transmission.

Determining Community Exposure

With an infectious disease like COVID-19, people may be contagious before they show any symptoms. Some may never show symptoms. To determine the true rate of community infection and to provide information to help public-health departments around the country to make the best decisions on directing resources, the EPA researchers have developed several ways to monitor exposure.

The EPA researchers are analyzing wastewater samples from communities in southwestern Ohio using a molecular approach to look for the genetic marker of SARS-CoV-2. This approach acts as an early warning system to alert public-health officials about increasing infection in a community. It can also serve to let the officials know when cases are dropping.

Researchers are also working on a standardized method that could quantify the level of live, or infectious, SARS-CoV-2 detected in raw sewage at wastewater treatment plants.

The EPA researchers have also developed a salivary antibody test that is simple, easy-to-collect, low-cost, and noninvasive. Antibody testing helps identify people who have been exposed to SARS-CoV-2 and have developed an immune response, but who might not have ever developed symptoms. This test can help public-health officials determine the rate of infection and provide insights on the true impact of the pandemic in communities across the country.

Research on Masks and PPE

Masks and social distancing have been important to reduce the risk of exposure to COVID-19. Researchers studied the effectiveness of different kinds of masks and facial coverings to help people decide which kind of masks to buy and wear to protect themselves and others.

Researchers also evaluated methods to disinfect used Personal Protective Equipment (PPE) and evaluated whether any of the disinfection methods causes damage to the PPE or limited its performance in reducing exposure to COVID-19. This information helps frontline workers such as healthcare staff and emergency responders when PPE are in limited supply. Proper cleaning and disinfection for PPE ensures continued protection from exposure to the disease.