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Full text release has been delayed at the author's request until April 25, 2025

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Investigating a representative ultraviolet filter release fraction used to estimate potential environmental emissions after dermal application of sun protection products

Carrao, Andrea
http://orcid.org/0000-0003-3971-787X
http://rave.ohiolink.edu/etdc/view?acc_num=ucin1712911687517675

Abstract Details

2024, PhD, University of Cincinnati, Pharmacy: Pharmaceutical Sciences.
Commercial sunscreen products have been developed to protect human skin from ultraviolet radiation (UVR) with the use of chemical ingredients known as ultraviolet filters (UVFs). Sunscreens are important in protecting human health by preventing skin cancer. However, there have been several scientific publications investigating the potential impact of UVFs on environmental health in recent years. In response to the growing concern, the National Academies of Sciences, Engineering, and Medicine (NASEM) published a review consensus report on this topic and one knowledge gap identified is the need to further research environmental emissions of UVFs. This doctoral research set out to investigate two variables important to environmental emissions estimates of sunscreen UVFs: the amount applied to the skin (i.e., application thickness) and the amount released from the skin (i.e., release percentage). The hypothesis that was tested is the assumption of 100% sunscreen and UVF release from the skin is not representative of real-world conditions and leads to over-estimates of direct environmental emissions of UVFs from sunscreens. Three different studies were designed and executed to test this hypothesis. A large-scale web-based survey was developed and fielded to participants with the aim to measure sunscreen application aided by a visual reference and determine a more representative overall value for the United States (US) population. In the end, three online surveys and one home usage study were conducted. Results of this research support the inference that consumers are not applying the US Food and Drug Administration recommended application of 2.0 mg/cm2 and individual sunscreen application is highly variable. Next, two sunscreen rinse-off and release experiments were conducted. An in vivo rinse-off experiment using human volunteers aimed to determine a baseline UVF release percentage. The data from these experiments determined the average UVF release percentage was 22-30% per UVF. Additionally, this study did not find a significant difference between the release percentages from a moisturizing SPF product and a water-resistant lotion product. Finally, an in vitro rinse-off experiment was conducted using Vitro-Skin as a skin-mimic alternative substrate. The UVF release percentage for the water-resistant product was less than the in vivo results (15-18%) while the UVF release percentage for the moisturizing SPF product was greater than the in vivo results (47-62%). Furthermore, this experiment found the moisturizing SPF product rinsed-off significantly more than the water-resistant product. Based on this research, it can be concluded that the environmental release of UVFs used in sunscreens and applied to the skin is not 100%. In addition, this data can be used to improve the environmental emissions estimates of UVFs in sunscreens. By changing the assumptions of application thickness and release percentage results, over a 10-fold decrease of estimated emissions per day per UVF is realized. Improved estimates can support more informed environmental risk management decisions and protection of both human and environmental health.
Harshita Kumari, Ph.D. (Committee Chair)
Kavssery Ananthapadmanabhan, ENG.SC.D. (Committee Member)
Carys Mitchelmore, Ph.D. (Committee Member)
Kevin Li, Ph.D. (Committee Member)
James Coleman, Ph.D. (Committee Member)
175 p.
Pharmaceuticals
consumer research; sunscreen; environmental safety; environmental exposure; ultraviolet filter; environmental risk assessment

Recommended Citations

Citations

  • Carrao, A. (2024). Investigating a representative ultraviolet filter release fraction used to estimate potential environmental emissions after dermal application of sun protection products [Doctoral dissertation, University of Cincinnati]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1712911687517675

    APA Style (7th edition)

  • Carrao, Andrea. Investigating a representative ultraviolet filter release fraction used to estimate potential environmental emissions after dermal application of sun protection products. 2024. University of Cincinnati, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=ucin1712911687517675.

    MLA Style (8th edition)

  • Carrao, Andrea. "Investigating a representative ultraviolet filter release fraction used to estimate potential environmental emissions after dermal application of sun protection products." Doctoral dissertation, University of Cincinnati, 2024. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1712911687517675

    Chicago Manual of Style (17th edition)

ucin1712911687517675
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This open access ETD is published by University of Cincinnati and OhioLINK.