Detection and Sizing of Ti-Containing Particles in Recreational Waters Using Single Particle ICP-MS

Abstract

Single particle inductively coupled plasma mass spectrometry (spICP-MS) was used to detect Ti-containing particles in heavily-used bathing areas of a river (Salt River) and five swimming pools. Ti-containing particle concentrations in swimming pools ranged from 2.8 × 10 to 4.4 × 10 particles/mL and were an order of magnitude lower than those detected in the Salt River. Measurements from the Salt River showed an 80% increase in Ti-containing particle concentration over baseline concentration during peak recreational activity (at 16:00 h) in the river. Cloud point extraction followed by transmission electron microscopy with energy dispersive X-ray analysis confirmed presence of aggregated TiO particles in river samples, showing morphological similarity to particles present in an over-the-counter sunscreen product. The maximum particle mass concentration detected in a sample from the Salt River (659 ng/L) is only slightly lower than the predicted no effect concentration for TiO to aquatic organisms (< 1 μg/L).

Assessing Sunscreen Lifecycle to Minimize Environmental Risk Posed by Nanoparticulate UV-Filters – A Review for Safer-by-Design Products

“…The available analytical methods are often not sensitive enough for current environmentally relevant concentrations and cannot distinguish natural materials in the nanoscale size range from manufactured nanomaterials (Englert, 2007;Domingos et al, 2009;Simonet and Valcarcel, 2009). Single particle (sp) ICP-MS is of particular interest in this context as it enables to detect and quantify Ti-containing particles of nanometric size at ppb/ppt levels in a complex liquid medium (Gondikas et al, 2014(Gondikas et al, , 2018Venkatesan et al, 2018). However, high resolution equipment may sometimes be required to solve isobaric interferences, such as 48 Ca with regard to 48 Ti, which can hamper the detection of titanium ENMs in waters containing high Ca concentrations, like river waters for instance (Tharaud et al, 2017).…”

Titanium dioxide nanoparticles impair the inner blood-retinal barrier and retinal electrophysiology through rapid ADAM17 activation and claudin-5 degradation

“…Approximately 20-40% of the initial amount of TiO 2 -NP was found to be released from sunscreen-applied skin after 120 min of stirring [26]. In addition, large amounts of TiO 2 -NPs are frequently present in swimming water (21-60 μg/L) and in surface water (2-700 ng/L) [27,28]. This makes eye-contact with TiO 2 -NPs inevitable.…”

Fueling a Hot Debate on the Application of TiO2 Nanoparticles in Sunscreen

“…These particles are believed to originate from sunscreen products as TEM images compare favorably with Ti-containing NPs from commercially available sunscreen. Interestingly, the Ti content in the swimming pools was dominated (98.7%–99.8%) by dissolved Ti species [120]. Holbrook et al also made a similar observation of dissolved Ti species in a swimming pool [121].…”

“…Sánchez et al estimated the summer daily release of TiO 2 NP of approximately 4 kg at Palmira beach (Peguera, Majorca Island) and estimated an associated increase of net hydrogen peroxide production rate of H 2 O 2 of 270 nM/day due to the redox activity of the material [119]. Venkatesan et al used single-particle inductively coupled plasma mass spectrometry to measure Ti-containing particles in heavily frequented bathing areas in Arizona—the Salt River and five swimming pools [120]. Between 64 to 148 ng/L of TiO 2 NP were found in the pools whereas 260–659 ng/L were found in the Salt River, this number bordering very close to the PNEC limit.…”

“…Between 64 to 148 ng/L of TiO 2 NP were found in the pools whereas 260–659 ng/L were found in the Salt River, this number bordering very close to the PNEC limit. The concentration range for the Salt River is expected to be underestimated value because it is possible that larger-sized particles may have been filtered out in the sample preparation process and smaller-sized particles are undetectable by the instrument [120]. These particles are believed to originate from sunscreen products as TEM images compare favorably with Ti-containing NPs from commercially available sunscreen.…”