Available at: https://digitalcommons.calpoly.edu/theses/1861
Date of Award
MS in Biological Sciences
The growing popularity of physical sunscreens will also lead to an increased release of the ingredients from zinc oxide (ZnO) sunscreens into marine environments. Though zinc (Zn) is a necessary micronutrient in the ocean, greater than natural Zn concentrations are being released into marine environments by use of sunscreens. The extent of the consequences of the addition of Zn to the ocean are not fully understood. We investigated effects of materials released by zinc oxide (ZnO) sunscreens on the development of California purple sea urchin, Strongylocentrotus purpuratus. Embryos developed in various concentrations of Zn, the sources of which included zinc-containing compounds: ZnO and ZnSO4; and ZnO sunscreens: All Good, Badger, and Raw Elements. ZnO sunscreens were slightly more toxic than ZnO and ZnSO4, suggesting that the sunscreens may release additional unknown materials that are detrimental to sea urchin embryo development. All concentrations of Zn exposure resulted in significant malformations (skeletal abnormality, stage arrest, axis determination disruption), which were identified using light and fluorescent confocal microscopy. Developing embryos internalize Zn2+in proportion to the concentration of Zn in their environment. Additionally, both ZnO sunscreens and ZnO and ZnSO4at 1ppm Zn, significantly increased calcein-AM (CAM) accumulation, indicating decreased multidrug resistant (MDR) transporter activity. This is the first research that we know of to show that ZnO sunscreens release high concentrations of Zn that are internalized by and have detrimental effects on aquatic organisms.