Publication Date


Document Type


First Advisor

Lenczewski, Melissa E.

Second Advisor

Luo, Wei

Degree Name

M.S. (Master of Science)

Legacy Department

Department of Earth, Atmosphere and Environment


Sunscreens and antibiotics are contaminants of emerging concern in groundwater, especially in areas with high tourism. The Riviera Maya in Quintana Roo, Mexico, is an international travel destination with a popular aquatic tourism industry. The region experienced a significant decrease in tourist visits during the COVID-19 pandemic, setting up a natural experiment to characterize the baseline contamination of groundwater in the absence of tourists. Additionally, municipalities installed new sewage disposal systems to combat the poor water quality due to inadequate septic systems and wastewater treatment plants. Water samples were collected during the pandemic from March 2020 to July 2021 from cenotes, beaches, and wells and were tested for antibiotics and active ingredients in sunscreens using liquid chromatography. The data showed significant levels of contamination from specific sunscreens and antibiotics during tourism’s downturn, magnitudes higher than during the rebound tourism season, with the types of sunscreens and antibiotics becoming diversified during tourism’s return. In the area of the new sewage connections, the contamination levels were less than what was found during the pandemic and those in areas of no connection. While tourists contribute to the diverse types of antibiotics and sunscreens, residents are a major contributor to the total concentrations of pollutants found in groundwater.


78 pages




Northern Illinois University

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In Copyright

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NIU theses are protected by copyright. They may be viewed from Huskie Commons for any purpose, but reproduction or distribution in any format is prohibited without the written permission of the authors.

Media Type


Included in

Hydrology Commons