Occurrence of eight UV filters in beaches of Gran Canaria (Canary Islands). An approach to environmental risk assessment

Highlights

• UV filters levels in beach waters of Gran Canaria Island have been monitored.

• Highest levels were obtained for BP-3, BMDBM and OC UV filters.

• First time that DHHB levels are reported in coastal waters.

• Higher UV-filters levels were found in “semi-enclosed” beaches compared to open beaches.

• A preliminary risk assessment approach was applied for BP-3, 4-MBC and EHMC.

Abstract

Due to the growing concern about human health effects of ultraviolet (UV) radiation, the use of UV filters has increased in recent decades. Unfortunately, some common UV filters are bioaccumulated in aquatic organisms and show a potential for estrogenic activity. The aim of the present study is to determine the presence of some UV filters in the coastal waters of six beaches around Gran Canaria Island as consequence of recreational seaside activities. Eight commonly used UV filters: benzophenone-3 (BP-3), octocrylene (OC), octyl-dimethyl-PABA (OD-PABA), ethylhexyl methoxy cinnamate (EHMC), homosalate (HMS), butyl methoxydibenzoyl methane (BMDBM), 4-methylbenzylidene camphor (4-MBC) and diethylamino hydroxybenzoyl hexyl benzoate (DHHB), were monitored and, with the exception of OD-PABA, all were detected in the samples collected. 99% of the samples showed some UV filters and concentration levels reached up to 3316.7 ng/L for BP-3. Environmental risk assessment (ERA) approach showed risk quotients (RQ) higher than 10, which means that there is a significant potential for adverse effects, for 4-MBC and EHMC for those samples with highest levels of UV filters.

Introduction

UV filters are compounds employed in sunscreen and cosmetic formulations to protect the human skin from ultraviolet (UV) radiation. In order to protect the skin from the entire spectral range, organic UVA and UVB filters are used together in products. UVA filters absorb radiation from 320 to 400 nm and UVB from 290 to 320 nm. Unfortunately, some of these compounds have undesirable effects on the skin such us sensitization, photoallergy or phototoxicity (Goossens et al., 1999, Giokas et al., 2007). Because of this, the European Community has established a list of UV filters allowed in cosmetic products and their maximum concentrations in ready-for-use preparations outlined in Annex VI of the Regulation on Cosmetic Products 1223/2009 (European Parliament, 2009). Some UV filters such as octocrylene (OC) and ethylhexyl methoxy cinnamate (EHMC) can be also used as UV light stabilizers in polymer-based products and some paints (Kameda et al., 2011). These compounds enter the aquatic media by wastewater treatment plants (WWTP) effluents (indirect input) or from skin washing during swimming, bathing or recreational activities (direct inputs). The presence of UV filters has been previously reported in coastal waters, river and lake waters, swimming pool waters, wastewaters (Poiger et al., 2004, Balmer et al., 2005, Giokas et al., 2004, Giokas et al., 2005, Cuderman and Heath, 2007), as well as in sediments (Jeon et al., 2006) and in biota (Balmer et al., 2005, Buser et al., 2006).

UV filters in seawater can be found dissolved in the liquid phase or adsorbed on particulate matter. High concentrations of common UV filters like benzophenone-3 (BP-3) or 4-methylbenzylidene camphor (4-MBC) have been measured in the unfiltered fraction of the surface microlayer. Because of their lipophilic characteristics, these compounds tend to be more concentrated in the surface microlayer and accumulated in soils and particles (Tovar-Sánchez et al., 2013).

Methodologies for the determination of UV filters in environmental samples have been previously reviewed (Salvador and Chisvert, 2005, Peck, 2006, Giokas et al., 2007). Common analytical methodologies for determination in water samples include an extraction-preconcentration first step by means of solid phase extraction (SPE) (Langford and Thomas, 2008, Bratkovics and Sapozhnikova, 2011), in order to achieve low method limits of detection (MLOD). It is followed by gas chromatography (GC) (Cuderman and Heath, 2007) or liquid chromatography (LC) analysis (Rodil et al., 2012) coupled to mass spectrometry detectors. Not all UV filters are amenable for GC, so LC is the most suitable technique for their determination. On the other hand, in relatively clean water matrices, such as bathing-waters, expensive and sophisticated mass spectrometry detectors are not necessary and more common detectors, such as UV-photodiode array (PDA), are adequate for the determination of sunscreen agents (Giokas et al., 2005).

The growing concern about the environmental implications of UV filters has increased the number of studies in recent years. Due to their high lipophilicity (log K_ow = 3−7) and stability in the environment, UV filters have been identified to have bioaccumulation factors greater than 5000 in fish (Brausch and Rand, 2011). Some of the UV filters such as 4-MBC and 3-benzylidene camphor have shown decreased reproduction and increased mortality rates of benthic organisms (Schmitt et al., 2008). In addition, some studies have indicated a significant potential for estrogenic activity (Schlumpf et al., 2001). In fact, benzophenone-1, BP-3, 4-MBC and EHMC have a similar estrogenic potential as well-known environmental estrogens like bisphenol A, methoxychlor, endosulfan or dibutylphthalate (Heneweer et al., 2005). Numerous UV filters can, potentially, cause coral bleaching (Danovaro et al., 2008) and estrogenic effects, and they may even adversely affect fecundity and reproduction in fish (Kunz et al., 2006, Coronado et al., 2008, Fent et al., 2008).

The Canary Islands is a Spanish archipelago located close to the northwest African coast, with tourism being the main economic activity of the region. It is the only European region where the bathing season is extended throughout all the year due to its mild weather. Moreover, Gran Canaria is one of most visited and populated island of the archipelago. Urban and resort areas are located close to the coast which are exposed to high human pressures. For this reason, the presence of new environmental pollutants is a priority that should be identified and controlled.

The aim of the present study was to determine the presence of eight common UV filters in the dissolved fraction of coastal waters from six beaches around Gran Canaria during 2011. Finally, an Environmental Risk Assessment (ERA) approach was used to evaluate the potential impact of quantified UV filters levels. To the best of our knowledge, this is the first study which reports measurable levels of some common UV filters in the waters surrounding the Canary Islands.