An outstanding Saharan dust event affected the Iberian Peninsula during winter 2016 (20 to 25 February). The impact of this event on ambient PM₁₀ surface levels and its spatial and temporal evolution was investigated by means of data from 250 air quality stations across mainland Spain and the Balearic Islands. The event had a significant impact on surface PM₁₀ levels, and on 22 February, 90% of the air quality monitoring sites registered PM₁₀ concentrations above the EU daily limit value of 50 μg/m³. The study of the attenuated backscattering vertical profiles associated with African dust evidenced a complex structure, with a thick aerosol layer that was at higher altitudes over the pre‐Pyrenees compared to the coastal area of Barcelona but closer to the surface than typically observed at both sites. Optical and physical properties of dust particles were investigated at the continental background Global Atmosphere Watch mountain observatory of Montsec (MSA) in the pre‐Pyrenees. Good agreement was found between in situ and passive remote sensing methodologies once the aloft dust layer reached the MSA station. Scattering Ångström exponent values decreased to values close to zero (even below zero for surface in situ measurements) indicating the predominance of coarse particles. On the contrary, absorption Ångström exponent values increased during the Saharan dust outbreak denoting an absorption enhancement at shorter wavelengths, characteristic of mineral dust particles. Furthermore, the performance of NMMB/BSC‐Dust and BSC‐DREAM8b models has been qualitatively evaluated for the dust spatial distribution across Spain and the vertical structure over MSA and Barcelona showing good agreement.

Over recent years, a technological revolution has taken place in which conventional lighting has been replaced by light emitting diodes (LEDs). Some studies have shown the possibility that blue light from these artificial sources could have deleterious effects on the retina. Considering that people spend a non-negligible time in front of screens from computers and mobile phones, the eyes receive blue light of different intensities depending on the source. Nevertheless, any study about the visual and non-visual effects of blue light must consider precise measurements taken from actual artificial sources. For this reason, we have analyzed the spectral emission of 10 different electronic devices and weighted them according to the hazard caused by blue light to the eyes, comparing the results with solar radiation simulated with a radiative transfer model. The maximum spectral irradiance of the measured electronic devices at 10 cm from the detector was located between 440 nm and 460 nm. The irradiance for blue light hazard ranged from 0.008 to 0.230 Wm⁻² depending on the particular characteristics of each electronic device. In contrast, the solar radiances in the same spectral range are larger both under clear and cloudy conditions.

One of the consequences of the COVID-19 lockdowns has been the modification of the air quality in many cities around the world. This study focuses on the variations in pollutant concentrations and how important meteorological conditions were for those variations in Barcelona and the surrounding area during the 2020 lockdown. Boundary-layer height, wind speed, and precipitation were compared between mid-March and April 2016–2019 (pre-lockdown) and the same period in 2020 (during lockdown). The results show the limited influence of meteorological factors on horizontal and vertical dispersion conditions. Compared with the pre-lockdown period, during lockdown the boundary-layer height slightly increased by between 5% and 9%, mean wind speed was very similar, and the fraction of days with rainfall increased only marginally, from 0.33 to 0.34, even though April 2020 was extremely wet in the study area. Variations in nitrogen dioxide ( $$\hbox {NO}_{{2}}$$NO 2 ), particulate matter with a diameter less than 10 $${\mu }$$μ m (PM10), and ozone ( $$\hbox {O}_{{3}}$$O 3 ) concentrations over a 10-year period showed a 66% reduction in $$\hbox {NO}_{{2}}$$NO 2 , 37% reduction in PM10, and 27% increase in $$\hbox {O}_{{3}}$$O 3 at a traffic station in Barcelona. The differences in the daily concentration cycle between weekends and weekdays were heavily smoothed for all pollutants considered. The afternoon $$\hbox {NO}_{{2}}$$NO 2 peak at the traffic station was suppressed compared with the average daily cycle. The analysis of ozone was extended to the regional scale, revealing lower concentrations at rural sites and higher ones in urban zones, especially in Barcelona and the surrounding area. The results presented not only complement previous air quality COVID-19 lockdown studies but also provide insights into the effects of road-traffic reduction.

The popularity of nail beauty has increased during the last few years in Spain, as well as in other countries. Nowadays there are a large number of nail dryer devices in the market with ultraviolet (UV) fluorescent lamps, light emitting diodes (LED) or a combination of both. The different spectral emissions of each individual nail dryer device require particular nail polishes, which are polymerized by specific wavelengths and a controlled exposure time to achieve the desired results. We have measured and analyzed the emission of 28 nail dryer devices currently in use in Spanish beauty centers. The emission of each individual nail dryer device showed a particular spectral distribution and maximum intensity, especially those with fluorescent lamps or LED/UV combinations. About 30% of the devices emitted more UV-A radiation than that received in Barcelona at solar noon in summer. Nevertheless, in all cases the erythemal irradiance was low, similarly to ambient values at solar noon in winter or when the solar altitude is low. The erythemal doses corresponding to a typical session were, therefore, lower than those received from sunlight at summer midday at equivalent exposure times. The biological irradiances for photoaging (skin sagging and elastosis) showed high variability depending on the device, especially for fluorescent lamps. Since the emission of LED-based devices is centered in the visible region, erythemal and photoaging irradiances were low. An analysis of the labelling showed that 85% of the devices had a visible label, although 23% contained some errors, according to the EN 60335-1 guideline.