Daniel Kanofsky and Mary E. Woesner: An Update to "A Fresh Air Approach to COVID-19”


        More than a year has passed since our essay was originally written. We wish to briefly revisit and reassess the treatment modalities we suggested. Have they been adopted? If so, what has been the outcome? They will be addressed in the order in which they were mentioned.


1) Exercising Outside.

        Being outside is recommended by public health authorities. There is a consensus that COVID-19 is much less transmissible in outdoor settings than indoors (Bulfone, Malekinejad, Rutherford and Razani 2020). At the time we wrote our essay, this was not known. Many parks, beaches and boardwalks were being closed to prevent the possibility of close social gathering. There are now fewer of these bans but, in general, exercise has not been recommended. Staff at California's Kaiser Permanente Hospital System recently compared sedentary COVID-19 patients with COVID-19 patients who did at least 150 minutes per week of moderate to strenuous exercise. The investigators identified 48,440 adult patients with a COVID diagnosis who completed a form indicating how much they exercised each week. The sedentary patients had a significantly greater risk of hospitalization (Odds Ratio=2.26), admission to an ICU (OR=1.73) and death (OR=2.45). The investigators concluded, “We recommend efforts to promote physical activity be prioritized by health agencies and incorporated into routine medical care” (Sallis, Young, Tartof et al. 2021). The researchers did not distinguish between indoor and outdoor exercise.


2) Smoking Cessation.

        Our recommendation to increase smoking cessation efforts has not been adopted. It has been confirmed that smokers have worse COVID-19 outcomes but not as great a difference as initially thought. It appears smokers have approximately twice the risk of progressing to severe or critical disease when compared with non-smokers and former smokers (Reddy, Charles, Sklavounos et al. 2020). Since the pandemic began, less emphasis has been placed on smoking cessation. One public health tobacco specialist said in an interview: “The messaging was along the lines of 'you're not alone. It's a stressful time. It's OK if you're not ready to quit now'” (Jaklevic 2021). It is not surprising to learn that US Department of the Treasury data show a 1% uptick in cigarette sales during the first 10 months of 2020 after 4% or 5% annual declines since 2015. It will be interesting and important to see how this uptick in smoking will affect annual cardiovascular mortality.


3) Open Air Treatment.

        “Open Air Treatment” is basically about exposure to fresh air and sunshine. It includes ventilation and filtration of air in buildings to dilute virus concentration and other pollutants. Ultraviolet radiation of circulating air acts as a disinfectant (CDC 2021). Exposing skin to sunshine can raise Vitamin D levels. This can also be accomplished by taking a vitamin D supplement. The value of optimizing vitamin D levels during the pandemic has generated ongoing controversy and research. Much of the world’s population is vitamin D deficient. Several National Health and Nutrition Surveys have estimated the prevalence of vitamin D deficiency in the United States to be 40% (Parva, Tadepulli, Singh et al. 2018). Vitamin D is an immune mediator. There is evidence it enhances natural immunity while, at the same time, inhibiting the production of pro-inflammatory cytokines. Can the risk of severe COVID-19 be reduced if vitamin D deficient individuals are supplemented with vitamin D? From the early stages of the pandemic, investigators have sought to determine if vitamin D deficiency is a risk factor, but the findings are inconsistent. Critics of the vitamin D hypothesis are leery of any studies other than large prospective randomized double-blind ones. Several have been initiated but, to our knowledge, none have been completed. The most recent retrospective study is from Israel. It followed 253 hospitalized COVID-19 patients. Vitamin D levels were drawn 14 to 730 days prior to a positive PCR test. When compared with mildly or moderately ill patients, those with severe or critical COVID-19 were more likely to be vitamin D deficient, with a pre-infection vitamin D level of less than 20 ng/ml. Odds ratio was 14.3. Mortality rates were 2.3% in the vitamin D sufficient group versus 25.6% in the vitamin D deficient group. Both comparisons have p values less than 0.001 (Dror, Morozov, Daoud et al. 2021).

        To date, the “Fresh Air Approach to COVID-19” has shown some promising results.


Daniel Kanofsky   

Mary E. Woesner



Bulfone TA, Malekinejad M, Rutherford GW, Razani N. Outdoor transmission of SARS-CoV-2 and other respiratory viruses: a systematic review. J Infect Dis 2020;223:550-61. 

CDC: Ventilation in Buildings. June 2, 2021. /www.cdc.gov/coronavirus/2019-ncov/community/ventilation.html 

Dror AA, Morozov NG, Daoud A, Daoud A, Namir Y, Orly Y, Shachar Y, Lifshitz M, Segal E, Fischer L. Mizrachi M, Eisenbach N, Rayan D, Gruber M, Bashkin A, Kaykov E, Barhoum M, Edelstein M, Sela E.  Pre-infection 25-hydroxyvitamin D3 levels and association with severity of COVID-19 illness. MedRxiv. June 7, 2021. www.medrxiv.org/content/10.1101/2021.06.04.21258358v1. 

Jaklevic MC. COVID-19 and the “last year” for smokers trying to quit. JAMA 2021;325:1929-30.

Parva NR, Tadepulli S, Singh P, Qian A, Joshi R, Kandala H, Nookala VK, Cheiyath P. Prevalence of vitamin D deficiency and associated risk factors in the US population (2011-2012). Cureus 2018;10(6):e2741. 

Reddy RK, Charles WN, Sklavounos A, Duff A, Seld PT, Klajuria A. The effect of smoking on COVID-19 severity: A systematic review and meta-analysis. J Med Virol 2021;93(2):1045-56. 

Sallis R, Young DR, Tartof Sy, Sallis JF, Sall J, Li Q, Smith GN, Cohen DA. Physical inactivity is associated with a higher risk for severe COVID-19 outcomes: a study in 48,440 adult patients. Br J Sports Med 2021;0:1–8.


August 19, 2021