The nature of the PM2.5 and PM10 varies enormously depending on the anthropogenic activities developed in the surrounding environment. These particles can include Hazardous Elements (HEs), such as heavy metals, which can be considered dangerous for the human health. For this reason, determining the nature of those HEs that are present in the surrounding atmosphere can help to comprehend possible emission sources and to establish new strategies to reduce air pollution. In this work, a cost-effective self-made passive sampler (SMPS) was tested as a tool to collect different size of PM containing metals as HEs. The SMPS was installed in a 20th century historic building (Punta Begona Galleries, Getxo, ~ Basque Country, Spain), located just in front of the sea and thus, immersed in a coastal environment. This location is affected by the activities developed in a marina and in a port, and by the diffuse influence of several industries and a power station. The annual average for PM10 and PM2.5 were approximately 22 mg/m3 and 10 mg/m3, respectively. For develop this study, non-invasive elemental (Scanning Electron Microscope coupled to Energy Dispersive X-ray Spectrometry) and molecular (Raman microscopy) microspectroscopic techniques were used. Thanks to this methodology it was possible to determine in PM10 and PM2.5, the presence of heavy metals such as Fe, Cr, Ti, Pb, Zn, Ce, etc., most of them as oxides but also embedded in different aggregations with aluminosilicates, phosphates, halides, sulfates, etc.

The objective was evaluate the carotenogenic activity of Dunaliella salina isolated from the artificial salt flats of municipality of Manaure (Department of La Guajira, Colombia). Two experimental testings were designed, in triplicate, to induce the reversibility of the cell tonality depending on the culture conditions. In the first test (A), to induce the reversibility from green to red tonality in D. salina cells, these were cultured in J/1 medium at a concentration of 4.0 M NaCl, 390 µmol m−2 s−1, 0.50 mM KNO3. In the second test (B), to induce the reversibility from red to green cell tonality, the cultures were maintained in J/1 medium 1 M NaCl, 190 µmol m−2 s−1, 5.0 mM KNO3 and pH 8.2. The population growth was evaluated by cell count and the pigment content was performed by spectrophotometric techniques. It was found that in both tests the culture conditions influenced the population growth and the pigments production of D. salina. There was a significant difference between the mean values of total carotenoids in the test A with 9.67 ± 0.19 μg/ml and second test with 1.54 ± 0.08 μg/ml at a significance level of p < 0.05. It was demonstrated that the culture conditions of test A induce the production of lipophilic antioxidants, among these carotenoids. The knowledge of the stressful conditions for the production of carotenoids from D. salina isolated from artificial saline of Manaure opens a field in implementation of this biotic resource for biotechnological purposes, production of new antibiotics, nutraceuticals and/or biofuels production.

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