Background: The severity and susceptibility to COVID-19 infection are the two main epidemiological factors influenced by the host and environmental factors. Environmental factors like drinking water fluoride levels have a direct role in depleting Vitamin D and serum calcium level in the body which were found to have a positive effect on the recovery from COVID-19.

Aim and Objective: To find out if there is any association between the severity of COVID-19 and ground water fluoride level among children and young adults in Karnataka.

Settings and Design: Ecological/Correlational study design

Methods: Ground water fluoride levels of districts of Karnataka was obtained from the Government of India Central Ground Water Board’s Ministry of Water Resources River Development and Ganga Rejuvenation Year Book 2016-17 and 2018-19 and data on COVID-19 mortality under the age group of 20 years was obtained from the media bulletin of The Ministry of Health and Family Welfare, Government of Karnataka.

Statistical analysis: Descriptive analysis was performed and Pearson’s correlation was used to find out the linear association between the variables.

Results: The higher percentage of death due to COVID-19 was observed among males (65.8%) of age 16-20 (52.6%) years and around 71.8% of COVID-19 associated death among children and young adults were not associated with any co-morbidity. The ground water fluoride levels exhibit statistically significant linear strong positive (r=+0.734; P=0.024) correlation with the Case Fatality Rate (CFR).

Conclusion: The severity of COVID-19 was observed to be severe in the high concentration of ground water fluoride areas in Karnataka.