Freshwater pH Impact on Anabaena Exposed to Coated and Uncoated Nano-Zinc Oxide

Sunscreen reduces the risk of developing melanoma (skin cancer). However, environmental sunscreen pollution is increasing at a rate that could damage aquatic environments without environmental regulations. This study focuses on the impacts of sunscreen chemicals, silane-coated and uncoated nanoparticulate Zinc oxide (nano-ZnO), on the growth rate of Anabaena in four different pH levels using water collected from Lake Murray, South Carolina. Anabaena was used to indicate how larger organisms would respond to similar metallic contaminants. It was determined that pH and coating on nano-ZnO particles both have a statistically significant impact on algae growth. These results indicate nano-ZnO chemicals negatively affect algae growth at the concentration of 0.03g per 37 mL in environmentally realistic conditions. The study also indicated that pH negatively impacts the dissolution of nano-ZnO particles. These results may be useful to legislative bodies considering sunscreen environmental regulations. It is also recommended that additional research is performed at different particle concentrations to determine the range of conditions that are least harmful for aquatic organisms.