Should we Close the Beaches?

Ever since the pandemic hit Orange County’s 8 beach cities (Seal Beach, Huntington Beach, Newport Beach, Corona del Mar, Laguna Beach, San Clemente, San Juan Capistrano, and Dana Point) have had a much higher incidence of positive cases. Based on data published by the County, as of April 15, 2020 beach cities averaged 65.9 confirmed cases per 100,000 compared to an average of 37.9 for the rest of the County.

I wanted to know whether or not this was unique to Orange County so I looked at the data in Los Angeles and San Francisco. In LA the 11 beach cities (Malibu, Manhattan, Redondo, Santa Monica, Venice, Palos Verdes Estates, Hermosa, Marina del Rey, Pacific Palisades, San Pedro, Rancho Palos Verdes) had an average rate of 80.86 per 100,000. The average for LA based on the 4,045 cases and the 10,000,000 people was 40.45. So the 11 LA beach cities averaged more than twice as high as the rest of LA County.

In San Francisco I compared 3 groups: counties that are primarily bay-front counties (San Mateo, Marin, Alameda, and San Francisco) vs counties that border the bay but have significant land area inland (Santa Clara, Napa, Contra Costa, Solano, Sonoma), vs nearby counties that don’t border on the bay (Stanislaus, San Joachim, Sacramento, Yolo). The averages were 66.6 vs. 38.1 vs. 30.8 per 100,000.

Whether you look at OC, LA or SF, cities that are ocean/bay front averaged about twice the incidence of confirmed cases when compared to non-waterfront cities.

Similar results can be found in the U.S. as a whole. The five most impacted cities are New York (340.1), New Orleans (192.3), Detroit (107.9), Seattle (89.3), and Boston (71.4) – all waterfront. Among the top 25 most impacted cities you can add waterfront cities like Chicago, Miami, Philadelphia, Buffalo, Cleveland, San Francisco, Baltimore, Washington D.C., and the list goes on. Among the least impacted major cities – Riverside, San Bernardino, San Antonio, Cincinnati, Richmond, Minneapolis, Sacramento, Grand Rapids, Austin, and Phoenix, Of course there are exceptions, but they are few.

Before you conclude that beach cities are denser, they’re not necessarily. In OC, for example, the beach cities average 4,223 people per square mile while the rest of the cities average 6,790. In LA, the beach cities averaged 6,661 people per square mile, while the rest of the cities averaged 8,454. Beach cities in Southern California are not more dense, though on a nationwide basis proximity to the water does result in higher density.

And while the beach cities do tend to have a higher median household income ($94,731 vs. $79,880), the correlation between Covid 19 incidence and household income is only 0.46 in OC.

So what’s going on with the beach cities? When we thought that the infection was transmitted through touch, the question remained dangling out there. Now that we know that it’s airborne, one can imagine that the beach breezes result in the airborne virus being carried further than it’s carried in other cities – 6 feet may not be effective in beach cities. This is only a hypothesis. Nonetheless, there is some past research to support the idea, including a study of wind influences on the spread of the avian virus in 2003 and work on malaria transmission in 2018.

Only a few days ago, Tia Ghose, Assistant Managing Editor of Life Science, said “We still don’t fully understand how the new coronavirus spreads…” That article suggests that the 6-foot rule is a guideline that might be outdated.

If ocean, bay and Great Lake breezes are assisting the virus to spread more extensively in these waterfront areas, which the data suggests, there are some steps to take now. The first is to encourage research on transmission by wind so we know what we’re dealing with. Perhaps in windy areas the distance is not 6 but 20 feet. Perhaps people who live in windy areas should wear masks anytime they go outside.

It will take some time to get this information. Meantime, on the chance that this hypothesis is correct, should beach access be closed to non-residents? Some steps have already been taken, but these steps are neither systematic nor being enforced. A complete shutdown may be called for. If enacted, restrictions can be loosened as the incidence decreases. Along with any shutdown, the authorities need to issue an alert that the possibility of winds transmitting the disease further than predicted means that people should adjust their behavior (distancing) accordingly.

If the hypothesis is correct, lives could be saved. If the hypothesis isn’t correct, little harm can be done from closing the beaches to non-residents or from increasing the distancing guidelines.

Dr. Jim Gardner is a Clinical Psychologist, a former University Professor, and the former Mayor of Lake Forest California.