In the recent years there have been some reports that using sunscreen may have serious side effects. A group of researchers from the JU Faculty of Pharmacy led by Prof. Elżbieta Pękala has lately begun investigating into new chemicals that would protect our skin without jeopardising nature or ourselves.
The history of suntan lotions dates back nearly 100 years. At first, they were meant to protect people from burns. It was only later that scientists proved that excessive exposure to the Sun’s rays may cause skin cancer. It’s estimated that people spent over 5.5 billion dollars on sunscreen in 2013 alone. However, a closer look at the substances used to produce them casts doubt on their apparent safety.
‘To say that sunscreen is completely safe is baseless. It was always considered safe simply because it hasn't been thoroughly and properly tested to see if it has any negative side effects’, stated Prof. Pękala. ‘Recently there have been many scientific papers suggesting that many of the substances used in suntan lotions can penetrate our skin and travel to our organs through the bloodstream.  Furthermore, there are sources that say some substances used to protect our skin from sunlight may potentially be neurotoxic  or affect our hormone regulation. [3, 4]
We also have to remember about the negative impact of chemicals on the environment. ‘In holiday resorts, millions of people put lotion on their skin. A lot of it ends up in the water – and later in the digestive systems of fish and crustaceans’, Prof. Pękala pointed out. She referred to the results of three analyses [5, 6, 7] that suggest detrimental substances from sunscreen are deposited in the bodies of marine animals, harming them and ultimately us, as we’re at the top of the food chain. Some scientists have put forward a hypothesis that when combined with other chemical compounds, several substances used in suntan lotions may be a factor in the growing phenomenon of infertility. 
Effective and 100% safe
‘These alarming news have inspired us to try and find new, much safer but equally effective means of UV protection. To combat the adverse effects of ultraviolet radiation, sunscreens must absorb this radiation in the UVA or UVB frequency and turn it into heat energy. To make that possible, each particle of the sunscreen has to be designed so that features double bonds, making it unsaturated’, Prof. Pękala explained. Kraków researchers are currently focused on two groups of such compounds, derivatives of cinnamic acid and 3-benzylidene camphor. They hope they’ll be able to synthesise new derivatives, eliminating harmful hormonal influence while retaining the effectiveness of UV protection.
Prof. Pękala’s group will perform rigorous testing on the substances they design. They will use cell model tests legally approved by the European Union. ‘We’ll check to see if of sunscreen harms the liver, nervous system and, naturally, skin. We’ll also check the levels of its mutagenicity and toxicity to make sure it doesn’t cause any mutations and increase the risk of cancer. It’s the standard procedure nowadays’, stated Prof. Pękala.
Scientists from the JU Department of Pharmaceutical Biology will no doubt face some challenges. They’re afraid that the substances they design may have a low lipophilicity (the ability of a chemical compound to dissolve in fats). This may prevent them from properly adhere to our skin. ‘Still, it may be better to apply sunscreen a few times a day than to expose youself to serious side effects’, Prof. Pękala said.
- . Janjua N.R et al., Sunscreens in human plasma and urine after repeated whole-body topical application, J Eur Acad Dermatol Venereol 2008 22(4): 456-461.
- . Broniowska Ż. et al., The effect of UV-filters on the viability of neuroblastoma (SH-SY5Y) cell line, Neurotoxicology 2016 54; 44-52.
- . Schlumpf M. et al., In vitro and in vivo estrogenicity of UV screen, Eviron Healt Perspect 2001 (3): 239-244.
- . Schlumpf M. et al. Endocrine activity and developmental toxicity of cosmetic UV filters – an update?, Toxicology 2004 205(1-2): 113-122.
- . Fent K. et al. Widespread occurrence of estrogenic UV-filters in aquatic ecosystems in Switzerland, Environ Pollut 2010 58(5): 1817-1824.
- . Kaiser D. et al. Ecotoxicological effect characterisation of widely used organic UV filters, Environ Pollut 2012 163: 84-90.
-  Mizukawa A. et al. Sediments as sink for UV filters and benzotriazoles: the case study of Upper Iguacu watershed, Curitiba (Brazil), Environ Sci Pollut Res 2017 DOI 10.1007/s11 3 56-017-9472-9.
- . Weisbrod C.J. et al., Effects of the UV filter benzophenone on reproduction fish, Toxicol Appl Pharmcol 2007 225(3): 255-266.
Original text: www.nauka.uj.edu.pl