Estimation of the Discharge of Sunscreens in Aquatic Environments of the Mexican Caribbean

Tourist growth in Quintana Roo, Mexico has brought with it an increase of pollution by sunscreens to aquatic ecosystems, which represents an environmental risk because of the chemical components of sunscreens that can negatively affect human health and aquatic ecosystems. However, the magnitude of pollution in aquatic environments is unknown. Consequently, we sought to estimate the contamination by sunscreens based on usage and tourism statistics. Our estimate indicates that the water in Quintana Roo will receive nearly 4367.25 tons of chemicals from sunscreens used by residents and tourists over a period of 18 years (2007 to 2025). On average, each tourist stays in Quintana Roo for 3.45 days, and 89.9% of these visitors apply sunscreen, although only the 83.7% engage in water activities. Additionally, 30.4% of residents engage in water activities for an average of 1.5 days/year. We considered direct sunscreen contaminant contamination, which occurs from the application of sunscreen and subsequent water activities, as well as indirect contamination, which occurs when people wash their skin with drinking water that then enters the drainage system. Our analysis indicated that the greatest contribution of sunscreen to the karst aquifer of Quintana Roo, is direct. Chemicals dissolved in water are a danger to aquatic life and human health.