Kovarik, William. “Ethyl-Leaded Gasoline: How a Classic Occupational Disease Became an International Public Health Disaster.” International Journal of Occupational and Environmental Health 11, no. 4 (2005): 384–97. https://doi.org/10.1179/oeh.2005.11.4.384.

Samizdat version: https://environmentalhistory.org/about/ethyl-leaded-gasoline/

Mehta, N., Rezaei, S., Puthillam, A., & Kapoor, H. (2022). Impact of Partisanship on Mobility in India during COVID-19. PsyArXiv. https://doi.org/10.31234/osf.io/p2jk6

Charles, S. J., Martin, J. A., Runicles, A., Chi, Z., Robertson, K., Barker, E. D., … Tye, C. (2022, February 1). Rare neurogenetic conditions and mental health of families during COVID-19. https://doi.org/10.31234/osf.io/teb7u

shinydoc. (2021, December 12). I love how I, an actual GP...who was involved in the initial covid vaccination programme ...has to tune in at 8pm with the public to find out that apparently we are vaccinating the entire adult population with boosters by the end of the year [Tweet]. @irishayesha. https://twitter.com/irishayesha/status/1470123478221303810

Take away: People are infectious for only part of the time they test positive. The tests for COVID-19 were granted emergency status by the FDA so some debate concerning the most ideal number of cycles is to be expected. It is worth noting that the FDA has the disclaimer "Negative results do not preclude 2019-nCoV infection and should not be used as the sole basis for treatment or other patient management decisions. Negative results must be combined with clinical observations, patient history, and epidemiological information (2)."

The claim: Up to 90 percent of people diagnosed with coronavirus may not be carrying enough of it to infect anyone else

The evidence: Per Walsh et al. (1), SARS-CoV-2 virus (COVID-19) is most likely infectious if the number of PCR cycles is <24 and the symptom onset to test is <8 days. RT-PCR detects the RNA, not the infectious virus. Therefore, setting the cycle threshold at 37-40 cycles will most likely result in detecting some samples with virus which is not infectious. As the PCR tests were granted emergency use by the FDA (samples include 2-9), it is not surprising that some debate exists currently about where the cycle threshold should be. Thresholds need to be set and validated for dozens of PCR tests currently in use. If identifying only infectious individuals is the goal, a lower cycle number may be justified. If detection of as many cases as possible to get closer to the most accurate death rate is the goal, setting the cycle threshold at 37-40 makes sense. A lower threshold will result in fewer COVID-19 positive samples being identified. It is worth noting that the emergency use approval granted by the FDA includes the disclaimer that a negative test does not guarantee that a person is not infected with COVID-19. RNA degrades easily. If samples are not kept cold or properly processed, the virus can degrade and result in a false negative result.

Source: 1 https://academic.oup.com/cid/advance-article/doi/10.1093/cid/ciaa638/5842165

2 https://www.fda.gov/media/134922/download

3 https://www.fda.gov/media/138150/download

4 https://www.fda.gov/media/137120/download

5 https://www.fda.gov/media/136231/download

6 https://www.fda.gov/media/136472/download

7 https://www.fda.gov/media/139279/download

8 https://www.fda.gov/media/136314/download

9 https://www.fda.gov/media/140776/download

Lee, Hyeon-seung, Derek Dean, Tatiana Baxter, Taylor Griffith, and Sohee Park. ‘Deterioration of Mental Health despite Successful Control of the COVID-19 Pandemic in South Korea’. Preprint. PsyArXiv, 30 August 2020. https://doi.org/10.31234/osf.io/s7qj8.

Daas, Chantal den, Gill Hubbard, Marie Johnston, and Diane Dixon. ‘Protocol CHARIS Study’. Preprint. PsyArXiv, 19 August 2020. https://doi.org/10.31234/osf.io/jnxcu.

Mulligan, C. B. (2020). Economic Activity and the Value of Medical Innovation during a Pandemic (Working Paper No. 27060; Working Paper Series). National Bureau of Economic Research. https://doi.org/10.3386/w27060

Plomecka, M., Gobbi, S., Neckels, R., Radziński, P., Skórko, B., Lazzeri, S., … Jawaid, A. (2020, May 5). Mental Health Impact of COVID-19: A global study of risk and resilience factors. https://doi.org/10.31234/osf.io/zj6b4

Wise, Toby, Giorgia Michelini, Tomislav Damir Zbozinek, Cindy C. Hagan, and Dean Mobbs. ‘Development and Validation of the Avoidance of Respiratory Viral Infection Scale (ARVIS)’, 17 July 2020. https://doi.org/10.31234/osf.io/dkc7m.

Gobbi, S., Plomecka, M., Ashraf, Z., Radziński, P., Neckels, R., Lazzeri, S., Dedić, A., Bakalović, A., Hrustić, L., Skórko, B., Es haghi, S., Almazidou, K., Rodríguez-Pino, L., Alp, A. B., Jabeen, H., Waller, V., Shibli, D., AghiliBehnam, M., Strutt, A. M., … Jawaid, A. (2020). Worsening of pre-existing psychiatric conditions during the COVID-19 pandemic [Preprint]. PsyArXiv. https://doi.org/10.31234/osf.io/x6cyg

Shevlin, M., McBride, O., Murphy, J., Gibson Miller, J., Hartman, T. K., Levita, L., … Bentall, R. (2020, April 18). Anxiety, Depression, Traumatic Stress, and COVID-19 Related Anxiety in the UK General Population During the COVID-19 Pandemic. https://doi.org/10.31234/osf.io/hb6nq

Cavojova, V., Šrol, J., & Mikušková, E. B. (2020, April 15). Scientific reasoning as a predictor of health-related beliefs and behaviors in the time of COVID-19. https://doi.org/10.31234/osf.io/tfy5q

Olapegba, P. O., Ayandele, O., Kolawole, S. O., Oguntayo, R., Gandi, J. C., Dangiwa, A. L., … Iorfa, S. K. (2020, April 12). COVID-19 Knowledge and Perceptions in Nigeria. https://doi.org/10.31234/osf.io/j356x