What to Look For & What to Avoid When Choosing A Sunscreen
Oxybenzone is a ubiquitous environmental contaminant – it is found in streams, rivers, lakes, and in marine environments from the Arctic Circle (Barrow, Alaska) to the beaches and coral reefs along the equator. It is considered an environmental hazard in many locations. It is found in very high concentrations in swimming pools and hot tubs and even in our drinking water. Swimmers directly contaminate water sources, but point and non-point sewage and treated waste-water effluent discharges are the largest source of contamination.
Oxybenzone can be absorbed directly through the skin, either from application of sunscreen product onto the skin, or by absorption from swimming in either swimming pools or along beaches. Oxybenzone in a commercial sunscreen formulation can transfer from the lotion or spray into the body, and be detected in urine within 30 minutes to several hours of application. Oxybenzone can both bioaccumulate, and can be biomagnified. Oxybenzone has been found in bird eggs, fish, coral, humans, and other marine mammals.
Oxybenone is found in many aquatic environments. It is found in parts per trillion concentrations off the coast of Barrow, Alaska, U.S.A, to parts per billion on coral reefs in the Caribbean, Pacific, and Red Sea. One of the highest concentrations measured in the marine environment was in Trunk Bay in the U.S. Virgin Islands National Park, in St. John Island, U.S. Virgin Islands. This beach can get between 2,000 to 5,000 people in a day.
Octinoxate is absorbed directly through the skin, via the application of sunscreens and other personal care products. Depending on the topical vehicle used, relatively little chemical (less than 1% to 6%) is absorbed into the skin and excreted in the urine, leaving 94% – 99% on the skin that can be washed off into various water sources. Octinoxate is a fat-soluble chemical, which means that some of it that absorbed by the body will be metabolized and excreted in urine, but much of it will be stored either in fat tissue or lipid-rich tissue such as the placenta.
Octinoxate may also bioaccumulate and be biomagnified in organisms. Biomagnification means Octinoxate may increase in concentration in the tissues of organisms as it travels up the food chain. A number of aquatic and marine species have been discovered to be contaminated, from carp, catfish, eel, white fish, trout, barb, chub, perch and mussels to coral, mahi-mahi, dolphins, sea turtle eggs, and migratory bird egg
In coral reef environments, Octinoxate can reach more than 10 parts per billion. Along the west coast of Maui in 2015, Hawaii, 11 coral reefs sites that were sampled had octinoxate concentrations from 6.9 parts per trillion to 1,516 parts per trillion.