Toxicity and Hazards of Biodegradable and Non-Biodegradable Sunscreens to Aquatic Life of Quintana Roo, Mexico

Sunscreens have spread widely into aquatic systems over the last 18 years in Quintana Roo, Mexico. This contamination is caused by intensive use as a result of leisure activities, as sunbathers apply the substances intensively (up to 83.75% of tourists and locals). Moreover, 25% of the compounds are mainly released into the water through topical products washing off. On average, 300,000 tourists arrive every week in Quintana Roo, increasing the contamination. In addition, there are no recent studies on sunscreen toxicity and the hazards this represents for the native zooplankton of Quintana Roo. In order to assess their adverse effects, acute toxicity was assessed for nine sunscreens (five non-biodegradable and four biodegradable) in four zooplankton species (Brachionus cf ibericus, Cypridopsis vidua, Diaphanocypris meridana, and Macrothrix triserialis). In total, 21 LC50 values were obtained, which are the baseline values for estimating risk and for determining the expected maximum permissible concentration. Our data on toxicity to freshwater species compared to marine species indicate that freshwater species are more sensitive than marine species. In conclusion, biodegradable sunscreen posed a moderate risk, and non-biodegradable posed a high risk. Our outcomes suggested that the maximum permissible concentrations for the contamination of sunscreens were 8.00E-05 g/L for non-biodegradable and 1.60E-04 g/L for biodegradable sunscreens.