Explainer: How masks can help prevent the spread of COVID-19

July 24, 2020

Currently, more than half of U.S. states have statewide mask mandates in place to curb the spread of the coronavirus. The governors of Alabama, Arkansas, Colorado, Indiana, Montana and Ohio all announced statewide mandates last week, bringing the total number of states requiring masks to 30. In addition to statewide mandates, some states and cities have placed certain areas under mask orders, as have many churches and businesses. On Monday, Walmart became the largest retailer to require customers at all of its stores in the U.S. to wear masks. 

How do masks prevent the spread of the coronavirus?

Medical researchers have clearly established that viruses, bacteria, and other pathogens can be transmitted when respiratory droplets escape from a person through such actions as breathing, coughing, sneezing, talking, or singing. Surprisingly, the small particles released through breathing, talking, and singing are potentially more infectious than the relatively larger sneeze or cough-generated droplets. Smaller particles persist in the air for longer time periods and can have a larger probability of penetrating further into the respiratory tract of a susceptible individual.

Scientists aren’t sure why, but the amplitude (loudness) of vocalization is directly correlated with the transmission of respiratory particles. Speaking can release about 2–10 times as many particles compared to coughing, while singing can release 6 times more particles than that emitted during normal talking. Research has also found that more particles are released when speech is voiced than whispered.

“A general rule for minimizing the spread of any respiratory virus,” says James Hamblin, a lecturer at Yale School of Public Health, “Whispering is safer than talking. Talking is safer than singing.”

When someone is breathing, speaking, coughing, or singing, only a tiny amount of what is coming out of their mouths is already in aerosol form. Nearly all of what is being emitted is droplets, which can then evaporate and turn into aerosolized particles that are 3- to 5-fold smaller. 

Because masks can block respiratory droplets emitted by the wearer when breathing or talking, they serve as a form of source control, preventing the transmission of the coronavirus that causes COVID-19. Wearing a mask as source control helps to stop this process from occurring, since big droplets dehydrate to smaller aerosol particles that can float for longer in air. 

What type of masks are effective at preventing the spread of the coronavirus?

The effectiveness of masks depends primarily on how well it prevents the transmission of respiratory droplets. 

A study conducted in April used laser light-scattering to sensitively detect droplet emission while speaking. Analysis showed that while significant levels of droplets were expelled

without a mask, virtually no droplets were expelled with a homemade mask consisting of a washcloth attached with two rubber bands around the head. The authors of the study state that “wearing any kind of cloth mouth cover in public by every person, as well as strict adherence to distancing and handwashing, could significantly decrease the transmission rate and thereby contain the pandemic until a vaccine becomes available.”

Multiple studies since then have found that the filtration effects of cloth masks is similar to surgical masks, and that almost any form of cloth masks that covers both the nose and mouth is sufficient to provide a form of source control for respiratory droplets. One exception is masks with valves, such as the N95 masks commonly used in construction to prevent the inhalation of dust. The one-way valves close when the wearer breathes in, but open when the wearer breathes out, allowing unfiltered air and droplets to escape.

If masks are effective, why did U.S. health officials change their guidance on wearing them?

In February and March, at the early stages of the pandemic, many health officials such as Dr. Anthony Fauci and U.S. Surgeon General Dr. Jerome Adams advised the general public not to wear face masks. The primary reason for that guidance was the belief that the virus could only be spread by coughing and sneezing, not by talking and breathing. Additionally, it was not fully known that the virus could be transmitted by people who had not shown symptoms of COVID-19. 

Health officials were also unaware that almost any cloth worn over the face could prevent transmission. At the time, they thought that healthy Americans would deplete the supply of medical masks and there would not be enough for those who were sick or who were caring for the sick.

Is wearing a mask safe, and does everyone need to wear one?

According to the Centers for Disease Control (CDC), children younger than 2 years old, anyone who has trouble breathing, and anyone who is unconscious, incapacitated, or otherwise unable to remove the cloth face covering without assistance should not wear masks. For all other groups, wearing a mask is safe and effective.

Properly worn (i.e., loosely fitted over mouth and nose) cloth masks do not allow the build up of harmful levels of carbon dioxide or cause hypoxia, a condition in which the body or a region of the body is deprived of adequate oxygen supply at the tissue level. Masks are also not harmful to you if you are sick with a cold or allergies (though you’ll want to avoid touching someone else’s mask who has been sick). Most people with mild asthma or well-controlled asthma can also wear a mask.

Elderly people should always wear masks in public since they are more susceptible to COVID-19. However, persons with Alzheimer’s or dementia may have a hard time comprehending why they have to wear a mask.

“There are a few people who are not capable of wearing a mask, but the overwhelming majority of people can wear a mask,” says Dr. Charles Lerner, a member of the Texas Medical Association’s COVID-19 task force. “Severe respiratory failure would be one of them. People who may have had some facial injuries.” Lerner, who specializes in infectious disease, says people with health concerns that prevent them from wearing masks usually can’t even leave the home.

As noted above, the purpose of masks is to prevent the spread of respiratory droplets, which are exponentially larger than oxygen molecules. There is therefore no reason to wear a mask that is so constricting that it would cut off one’s own air supply. Masks primarily prevent someone who may have COVID-19 and not be aware of it from spreading the disease to others. But the masks may also protect the wearer by serving as a barrier and preventing them from breathing in respiratory droplets from infected carriers.

What would be the outcome if more people wore masks?

If more Americans wore masks, the number of new COVID-19 cases might drop so low that churches, schools, and businesses could reopen. 

To understand why this is the case, we need to understand the transmission rate of this coronavirus. The number of cases, on average, an infected person will cause during their infectious period is known as R₀  (pronounced “R naught”). A conservative estimate is that the R₀ of COVID-19 is 2.4, meaning an infected person will spread the virus to 2.4 other people.  If 50% of a given population were to regularly wear masks and the masks were only 50% effective in stopping the transmission of the virus, it would reduce the R₀ of COVID-19 to 1.35.

To put this in perspective, at R₀ of 2.4, 100 cases at the start of a month becomes 31,280 cases by the month’s end. In contrast, at R₀ of 1.35 means 100 cases at the start of a month becomes only 584 cases by the end of the month. As a team of medical researchers have noted, “Such a slowdown in case-load protects healthcare capacity and renders a local epidemic amenable to contact tracing interventions that can eliminate the spread entirely.”

In other words, wearing masks is one of the single most important effective means of stopping the spread of COVID-19. If 95% of Americans wore face masks in public, it could prevent more than 45,000 deaths by Nov. 1, according to the University of Washington’s Institute for Health Metrics and Evaluation.

The “Three W’s to ward off COVID-19” are: wearing a mask, washing your hands, and watching your distance. “But of the three, the most important thing is wearing a mask,” says infectious disease specialist Peter Chin-Hong. 

“You should always wear masks and socially distance,” adds epidemiologist George Rutherford. “I would be hesitant to try to parse it apart. But, yes, I think mask wearing is more important.”

What should Christians think about wearing masks?

As ERLC President Russell Moore recently said,

“I don’t like wearing a mask either—who does? But putting one on every day can remind me that my life is not just about my own preferences. I don’t exist in a computer simulation, but in a community. Even if you don’t accept the scientific consensus on masks (and I do), the principle is still valid. Jesus refused to submit to anything that would cause him to sin or that would deter his mission to the cross. When asked not to heal, he healed. When asked not to preach, he preached. When asked to be quiet in the temple, he caused a ruckus.

“And yet, Jesus willingly accepted all sorts of restrictions and inconveniences for the sake of others. Regarding the temple tax, for instance, Jesus said to Simon Peter: “What do you think Simon? From whom do the kings of the earth take toll or tax, from their sons or from others?” When Peter said from others, Jesus replied, “Then the sons are free.” That was not the end of the matter for him, though. “However, not to give offense to them, go to the sea and cast a hook and take the first fish that comes up, and when you open its mouth you will find a shekel. Take that and give it to them for me and for yourself” (Matt. 17:24-27). And this was a matter that did not—even arguably—jeopardize anyone’s life. How much more so can we endure a momentary burden for the sake of not just vulnerable people but the hospital personnel you are tasked with caring for the sick.”

Article 12: The Future of AI

We affirm that AI will continue to be developed in ways that we cannot currently imagine or understand, including AI that will far surpass many human abilities. God alone has the power to create life, and no future advancements in AI will usurp Him as the Creator of life. The church has a unique role in proclaiming human dignity for all and calling for the humane use of AI in all aspects of society.

We deny that AI will make us more or less human, or that AI will ever obtain a coequal level of worth, dignity, or value to image-bearers. Future advancements in AI will not ultimately fulfill our longings for a perfect world. While we are not able to comprehend or know the future, we do not fear what is to come because we know that God is omniscient and that nothing we create will be able to thwart His redemptive plan for creation or to supplant humanity as His image-bearers.

Genesis 1; Isaiah 42:8; Romans 1:20-21; 5:2; Ephesians 1:4-6; 2 Timothy 1:7-9; Revelation 5:9-10

Article 11: Public Policy

We affirm that the fundamental purposes of government are to protect human beings from harm, punish those who do evil, uphold civil liberties, and to commend those who do good. The public has a role in shaping and crafting policies concerning the use of AI in society, and these decisions should not be left to those who develop these technologies or to governments to set norms.

We deny that AI should be used by governments, corporations, or any entity to infringe upon God-given human rights. AI, even in a highly advanced state, should never be delegated the governing authority that has been granted by an all-sovereign God to human beings alone. 

Romans 13:1-7; Acts 10:35; 1 Peter 2:13-14

Article 10: War

We affirm that the use of AI in warfare should be governed by love of neighbor and the principles of just war. The use of AI may mitigate the loss of human life, provide greater protection of non-combatants, and inform better policymaking. Any lethal action conducted or substantially enabled by AI must employ 5 human oversight or review. All defense-related AI applications, such as underlying data and decision-making processes, must be subject to continual review by legitimate authorities. When these systems are deployed, human agents bear full moral responsibility for any actions taken by the system.

We deny that human agency or moral culpability in war can be delegated to AI. No nation or group has the right to use AI to carry out genocide, terrorism, torture, or other war crimes.

Genesis 4:10; Isaiah 1:16-17; Psalm 37:28; Matthew 5:44; 22:37-39; Romans 13:4

Article 9: Security

We affirm that AI has legitimate applications in policing, intelligence, surveillance, investigation, and other uses supporting the government’s responsibility to respect human rights, to protect and preserve human life, and to pursue justice in a flourishing society.

We deny that AI should be employed for safety and security applications in ways that seek to dehumanize, depersonalize, or harm our fellow human beings. We condemn the use of AI to suppress free expression or other basic human rights granted by God to all human beings.

Romans 13:1-7; 1 Peter 2:13-14

Article 8: Data & Privacy

We affirm that privacy and personal property are intertwined individual rights and choices that should not be violated by governments, corporations, nation-states, and other groups, even in the pursuit of the common good. While God knows all things, it is neither wise nor obligatory to have every detail of one’s life open to society.

We deny the manipulative and coercive uses of data and AI in ways that are inconsistent with the love of God and love of neighbor. Data collection practices should conform to ethical guidelines that uphold the dignity of all people. We further deny that consent, even informed consent, although requisite, is the only necessary ethical standard for the collection, manipulation, or exploitation of personal data—individually or in the aggregate. AI should not be employed in ways that distort truth through the use of generative applications. Data should not be mishandled, misused, or abused for sinful purposes to reinforce bias, strengthen the powerful, or demean the weak.

Exodus 20:15, Psalm 147:5; Isaiah 40:13-14; Matthew 10:16 Galatians 6:2; Hebrews 4:12-13; 1 John 1:7 

Article 7: Work

We affirm that work is part of God’s plan for human beings participating in the cultivation and stewardship of creation. The divine pattern is one of labor and rest in healthy proportion to each other. Our view of work should not be confined to commercial activity; it must also include the many ways that human beings serve each other through their efforts. AI can be used in ways that aid our work or allow us to make fuller use of our gifts. The church has a Spirit-empowered responsibility to help care for those who lose jobs and to encourage individuals, communities, employers, and governments to find ways to invest in the development of human beings and continue making vocational contributions to our lives together.

We deny that human worth and dignity is reducible to an individual’s economic contributions to society alone. Humanity should not use AI and other technological innovations as a reason to move toward lives of pure leisure even if greater social wealth creates such possibilities.

Genesis 1:27; 2:5; 2:15; Isaiah 65:21-24; Romans 12:6-8; Ephesians 4:11-16

Article 6: Sexuality

We affirm the goodness of God’s design for human sexuality which prescribes the sexual union to be an exclusive relationship between a man and a woman in the lifelong covenant of marriage.

We deny that the pursuit of sexual pleasure is a justification for the development or use of AI, and we condemn the objectification of humans that results from employing AI for sexual purposes. AI should not intrude upon or substitute for the biblical expression of sexuality between a husband and wife according to God’s design for human marriage.

Genesis 1:26-29; 2:18-25; Matthew 5:27-30; 1 Thess 4:3-4

Article 5: Bias

We affirm that, as a tool created by humans, AI will be inherently subject to bias and that these biases must be accounted for, minimized, or removed through continual human oversight and discretion. AI should be designed and used in such ways that treat all human beings as having equal worth and dignity. AI should be utilized as a tool to identify and eliminate bias inherent in human decision-making.

We deny that AI should be designed or used in ways that violate the fundamental principle of human dignity for all people. Neither should AI be used in ways that reinforce or further any ideology or agenda, seeking to subjugate human autonomy under the power of the state.

Micah 6:8; John 13:34; Galatians 3:28-29; 5:13-14; Philippians 2:3-4; Romans 12:10

Article 4: Medicine

We affirm that AI-related advances in medical technologies are expressions of God’s common grace through and for people created in His image and that these advances will increase our capacity to provide enhanced medical diagnostics and therapeutic interventions as we seek to care for all people. These advances should be guided by basic principles of medical ethics, including beneficence, non-maleficence, autonomy, and justice, which are all consistent with the biblical principle of loving our neighbor.

We deny that death and disease—effects of the Fall—can ultimately be eradicated apart from Jesus Christ. Utilitarian applications regarding healthcare distribution should not override the dignity of human life. Fur- 3 thermore, we reject the materialist and consequentialist worldview that understands medical applications of AI as a means of improving, changing, or completing human beings.

Matthew 5:45; John 11:25-26; 1 Corinthians 15:55-57; Galatians 6:2; Philippians 2:4

Article 3: Relationship of AI & Humanity

We affirm the use of AI to inform and aid human reasoning and moral decision-making because it is a tool that excels at processing data and making determinations, which often mimics or exceeds human ability. While AI excels in data-based computation, technology is incapable of possessing the capacity for moral agency or responsibility.

We deny that humans can or should cede our moral accountability or responsibilities to any form of AI that will ever be created. Only humanity will be judged by God on the basis of our actions and that of the tools we create. While technology can be created with a moral use in view, it is not a moral agent. Humans alone bear the responsibility for moral decision making.

Romans 2:6-8; Galatians 5:19-21; 2 Peter 1:5-8; 1 John 2:1

Article 2: AI as Technology

We affirm that the development of AI is a demonstration of the unique creative abilities of human beings. When AI is employed in accordance with God’s moral will, it is an example of man’s obedience to the divine command to steward creation and to honor Him. We believe in innovation for the glory of God, the sake of human flourishing, and the love of neighbor. While we acknowledge the reality of the Fall and its consequences on human nature and human innovation, technology can be used in society to uphold human dignity. As a part of our God-given creative nature, human beings should develop and harness technology in ways that lead to greater flourishing and the alleviation of human suffering.

We deny that the use of AI is morally neutral. It is not worthy of man’s hope, worship, or love. Since the Lord Jesus alone can atone for sin and reconcile humanity to its Creator, technology such as AI cannot fulfill humanity’s ultimate needs. We further deny the goodness and benefit of any application of AI that devalues or degrades the dignity and worth of another human being. 

Genesis 2:25; Exodus 20:3; 31:1-11; Proverbs 16:4; Matthew 22:37-40; Romans 3:23

Article 1: Image of God

We affirm that God created each human being in His image with intrinsic and equal worth, dignity, and moral agency, distinct from all creation, and that humanity’s creativity is intended to reflect God’s creative pattern.

We deny that any part of creation, including any form of technology, should ever be used to usurp or subvert the dominion and stewardship which has been entrusted solely to humanity by God; nor should technology be assigned a level of human identity, worth, dignity, or moral agency.

Genesis 1:26-28; 5:1-2; Isaiah 43:6-7; Jeremiah 1:5; John 13:34; Colossians 1:16; 3:10; Ephesians 4:24