# Traveling By Air In The Time Of Covid

(Posted on Tuesday, June 16, 2020)

Doubtless, many of you miss air travel for families, business or pleasure. I certainly do. Yet in this time of Covid, short of a hospital or nursing home, an airplane is a most dangerous place.

When you’re in an enclosed space, there is a formula for probability of infection which I developed that looks like this:

Probability of infection (PI) = Time of exposure (T), divided by distance between people (D), times the number of people in the space (N), times the number of people without a mask (NM), times the prevalence of the average daily infection in the population (P) over a period of ten days (incubation period).

So the equation would look like this:

PI= (T/D) x (N) x (NM) X (P x 10)

The exact number you end up with is less important than whether or not the number is relatively low, under 100, or higher. If it’s a number that ends up in the thousands or, worse yet, in the millions, you should be extremely cautious.

For air travel:

The time of exposure is long.

The distance between people is short.

The number of people in the enclosed space is high.

The number of people without masks will be variable but is almost definitely going to be greater than zero.

The prevalence of the average daily infection within the population is rising. There are roughly 200,000 people in the US actively infected today and 1,250,000 across the world and the number is rising.

Yesterday, the number of new cases of Covid-19 in the US was more than 25,000 and that number is steadily rising. Worldwide yesterday, there were 140,000 new infections – the largest number of new infections in any day since the start of the outbreak.

In almost every case of air travel, the probability for infection is high.

If you must travel, you must be extra vigilant. Read through online resources for how to protect yourselves and those around you. The US Centers for Disease Control has created a website with issues you should consider before flying. While you can implement many protective measures—booking the window seat, wearing a mask, social distancing whenever possible, and maintaining good hand hygiene—you will not be able to eliminate the risk entirely.

My advice, if you can, stay home and stay isolated. My mantra is: assume everyone you meet is infected because some surely are. Now is not the time for unnecessary air travel, it is a time for vigilance and caution.

*This article originally appeared in Forbes.*