## Fourteen mathematicians and biostatisticians have joined forces to help businesses reopen safely.

[Photo: Flickr user Peter Burka]

Math to the rescue! Fourteen mathematicians and biostatisticians have joined forces to help businesses reopen safely.

The group created a set of mathematical models tracing both business profits and infection risk of COVID-19 under varying scenarios. The results, published in Frontiers in Applied Mathematics and Statistics, are useful: Businesses can operate successfully while preventing outbreaks—but only by following broad safety measures.

## The safety measures

1. Social distancing
2. Robust sanitation of high-touch and shared spaces
3. Accessible COVID-19 tests for symptomatic or exposed workers (necessary to confirm cases)
4. A policy for case reporting and quarantine
5. A work-from-home policy for as many employees as is feasible
6. Mask, glove, and goggle wearing when not alone, along with frequent handwashing
7. Fever scanning (they suggest a Kinsa smart thermometer)
8. 30% lower working hours to lower exposure
9. Quality ventilation equipment (UV purification system, new system)

The authors created equations for infectious, quarantined, deceased, recovered, and at-risk employees within companies, while also accounting for “silent spreaders”; they also modeled profits while incorporating costs from safety measures, closures, and limited working hours. When running the numbers for a well-known, large Texas company, they considered three scenarios:

• No safety measures: Workers die; the company does not. The company’s infection rates rose to 30 times the U.S. rate with a catastrophic number of deaths, though profits remained high.
• All safety measures: The company remained over 100 times below the U.S. infection rate, and profits remained high and stable.
• Some safety measures: Good news! When a company follows measures No. 1-No. 6, removing only the most expensive measures (No. 7- No. 9), results are notably similar to all-safety-measures option. Employees remained safe and profits stable. But if PPE is removed (masks, gloves, goggles), the business becomes a hotspot. (Also, this is not to say that buildings with poor ventilation shouldn’t prioritize improving air circulation, because they absolutely should.)

Disclaimers: The equations assume that employees actually follow the guidelines. And, mathematicians and business professors have a long history of irking epidemiologists by swooping in with modeling that fails to correspond with on-the-ground disease spread. Lastly, models are just models. But these are a smart stamp of reopening approval. In short: Proceed with caution.