Saliva samples will be collected in Guam and Saipan in 20 mL conical polypropylene tubes which will be initially stored at -20°C. Aggregated samples will be shipped to Hawaii via FedEx. Shipments will be performed whenever 50-60 samples are successfully collected. After arriving in Hawaii, samples will be stored in Dr. Adrian Franke's lab at -80°C until analysis. All samples available at Dr. Adrian Franke's lab will be analyzed in one batch at the end of each annual cycle of the study.