Environmental Management for Coronavirus

There have been a lot of official recommendations and news coverage about how to clinically minimize Coronavirus, COVID-19. But what about how the virus affects the indoor environment? This article will review the background of the pandemic and discuss how to manage it within the built environment.

Dr. Rajiv Sahay, FIAS, CIAQP, Director, Environmental Diagnostics Laboratory

Background

In late 2019, the World Health Organization (WHO) identified a novel Coronavirus initially known as 2019-n CoV and later renamed to COVID-19 in Wuhan, China. A group of people showed pneumonia-like symptoms and they were associated with a seafood and live animal market in Wuhan. The WHO classified the outbreak caused by COVID – 19 as a pandemic on March 11, 2020. Typically, a pandemic is a situation where an infection can cause disease or death and sustain transmission between people, and it must be spreading in multiple countries.

This virus can cause pneumonia-like symptoms, upper respiratory infection in humans (stuffy nose, cough, sore throat, etc.), and shortness of breath. It may also cause middle ear infections in children. Generally, symptoms are mild but can be fatal in immunocompromised individuals and the elderly.

What is Coronavirus?

Coronavirus was first identified in the 1960s. The structure of the virus is spherical or pleomorphic envelope which appears with halo-like projections (crown-like) and containing single-stranded RNA. The name Coronavirus was adopted due to the virus’ crown-like shape (“Corona” is Latin for crown). They are zoonotic, meaning they are transmitted between animals and people. It is believed that the family of this virus circulate in a range of animals such as Camels, Cats, Ducks, Bats etc. Spillover of this virus from animals might have caused this episode of infection, however, the source of this COVID-19 remains unknown. In the United States, this group of viruses is commonly active during the fall and winter, but anyone can be infected with it at any time during the year.

Transmission of Coronavirus?

All the possible modes of transmission have yet to be determined. Generally, spreading of this virus is usually reported from one infected person to another. Common activities by which the infection can also be transmitted are inhalation of contaminated air (due to coughing and sneezing by infected individuals), close contact with infected persons such as touching and shaking hands, touching surfaces or infected objects and touching your mouth, nose, or eyes before washing your hands. It may be transmitted through fecal contact, though this method of infection is rare.  The group of people who are most at risk are those in close contact with live animals, animal market workers and care givers to the infected person(s) such as family members and healthcare professionals.

COVID-19 and HVAC Hygiene?

Droplets generated from a person infected with coronavirus are identified as the primary source of dissemination and accumulation in the occupied space. While most of the larger droplets travel short distances (< 1 m), some of the smaller size nuclei may enter in air-conveyance systems only to settle on coils, ducts and other HVAC components due to favorable conditions (including biologically active materials) or spread through ductwork of air distribution systems. A wide range of biologically significant entities such as viruses, bacteria, mold, mites, insects, protozoa, algae, cystic life forms and others are generated especially in damp and dirty duct systems. Both residential, commercial, or institutional settings can provide a breeding ground that can promote the transmission of such infectious or disease-causing agents including viruses. The viruses can remain in the building if they are not removed appropriately from the air circulation, especially where ventilation is mechanically controlled.  It is estimated that typically the air change rate (ACR) is four times per hour in a mechanically ventilated building; however, it may be up to 8-10 times in hospital and other healthcare settings.

Coronavirus Risks Management?

This virus is diagnosed with a test called Polymerase Chain Reaction (PCR) using a genetic fingerprint. At this time, no specific treatment is known for COVID-19 nor has any vaccine been made publicly available. The World Health Organization suggests that anyone with underlying medical conditions or with a compromised immune system should avoid live animal markets and raw meats altogether as they are “considered at higher risk of severe disease”. It is highly encouraged to adapt the two-fold approach to minimize the transmission of this virus.

Increase in Personal Hygiene practices

Following hygiene practices can be adapted as a habit to decrease the transmission and the likelihood of contraction of this virus:

• Avoid close contact with others infected with COVID-19
• Protect others by staying home while you are sick (if you have symptoms as mentioned)
• Cover your mouth and nose with a tissue when you cough or sneeze
• Properly dispose used tissue in the trash
• Wash your hands frequently with soap and water
• Use hand sanitizer before touching your nose, eyes, mouth, etc.
• Disinfect frequently used objects and surfaces
• Avoid traveling to an infected zone

Environmental Hygiene Practices

Environmentally friendly disinfecting techniques are very useful in preventing and minimizing Coronavirus risks. High touch surfaces in occupied spaces such as wall surfaces, doors, windows, knobs, furniture and others should be disinfected to maintain and manage good Indoor Environmental/Air Quality (IEQ/IAQ). For good IEQ/IAQ practices, it is encouraged to evaluate the hygienic conditions of HVAC system along with occupied space in the event of undesirable sanitary conditions due to both a-biological and biological contaminants for a proper remediation.

A special resource page and multi-level approach to building decontamination can found found HERE.

Finally, attempts are currently being undertaken by governmental and non-governmental organizations to develop a vaccine and treatment. In the meantime, steps must be for environmental management of Coronavirus.