Future of Earth the ozone layer that protects the surface from ultraviolet (UV) radiation from the Sun. An increase in UV-B radiation of only 10–30% is sufficient to cause a significant impact to life; particularly to the phytoplankton that form the base of the oceanic food chain. A supernova explosion at a distance of 26 light years will reduce the ozone column density by half. On average, a supernova explosion occurs within 32 light years once every few hundred million years, resulting in a depletion of the ozone layer lasting several centuries. Over the next two billion years, there will be about 20
UV filter differ in biological behavior and effects. Swimming pool water is usually disinfected by chlorination, bromination, ozonation or UV radiation. Upon the presence of some UV filters such as Avobenzone in swimming pools, toxic products are produced as a result of the interaction between Avobenzone and the active chlorine and UV radiation. Benzophenones (BPs) are widely used in UV filters, fragrance enhancers,and plastic additives. The major sources of BP-3 are reported to be human recreational activities and wastewater treatment plant (WWTP) effluents.The anionic forms of both BP-3 and 4-OH-BP3 can undergo direct photodegradation. The photolytic rates of both compounds in natural