Instrument for measurement of singlet oxygen for studies of skin under UVA irradiation

In this paper we will describe a non-intrusive, optically-based instrument that can quantitatively measure singlet molecular oxygen, a constituent of reactive oxygen species (ROS) produced by irradiation of human skin by the longer wavelength UV radiation known as UVA. UVA is causally associated with DNA damage and subsequent development of melanoma. We will present data from healthy human subjects that show formation of singlet molecular oxygen and concomitant production of thymine dimers, indicative of DNA damage. We will also discuss how this instrument may be a valuable tool for the development of more effective sunblock formulations for UVA.