I want to share this paper about a chemical called benzophenone, which can be absorbed by our body as a result of applying sunscreen products to our skin. I think this study is very interesting because it is closely associated with everyday life and my research focus, the exposome and health.
The exposome consists of all the environmental exposures one may encounter throughout their lifetime. Environmental exposures or toxicants may enter the body through various routes, including inhalation, dermal absorption, ingestion, and injections. Contaminants or toxicants in skincare products enter the body mainly through skin absorption and may cause undesirable health effects.
Octocrylene is one of the active ingredients used in sunscreens, moisturizers, and lip balms. Benzophenone is a known contaminant of octocrylene and is associated with genotoxicity, carcinogenicity, and endocrine disruption. While octocrylene can be absorbed by the skin, additional benzophenone comes from octocrylene degradation.
The authors analyzed 17 sunscreen products purchased from European and US markets. Benzophenone was detected in 16 product lines with an average of 39 mg/kg. The average concentration increased to 79 mg/kg in the accelerated stability test.
The paper raises an interesting question as to whether octocrylene-containing products are safe as skincare products. Though there’s no FDA ruling on this matter, it’s certainly worth investigating as products containing octocrylene are banned in some regions due to environmental hazardousness and there is zero tolerance of benzophenone as a food additive.
While manufacturers need a new purification method to purify octocrylene, as everyday consumers, we may reconsider our choice of sunscreen, what’s safe for us and the environment. Consumers can choose to use chemical sunscreens without octocrylene, or switch to physical sunscreens, which use zinc oxide or titanium dioxide to form a physical shield on the skin.
Dr. Allison Zhang is the scientist leading the ongoing study that hypothesizes patients who develop Crohn’s disease in youth may have been exposed to biological or chemical agents through the air or direct contact, contributing to their disease course. This study examines the exposures that humans face in their physical environment, and how it might affect their microbiome.
She joined Dr. Michael Snyder’s lab in 2018 at Stanford University. Her research focuses on understanding the exposome, particularly, how the exposome affects human health. She has studied the human exposome in multiple environmental settings, including hospitals and during the wildfire, and in diseases, such as Crohn’s disease. Her current work includes developing wearable sensors to profile the human exposome that aid precision environmental health.