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Speciated coarse particulate matter (PM 10 ) data obtained at three air quality monitoring sites in a highly industrialized area in Spain between 2002 and 2007 were analyzed for assessing source contribution of ambient particulate matter (PM). The source apportionment of PM in this area is an especially difficult task. There are industrial mineral dust emissions that need to be separately quantified from the natural sources of mineral PM. On the other hand, the diversity of industrial processes in the area results in a puzzling industrial emissions scenario. To solve this complex problem, a two-step methodology based on the possibilities of the Multilinear Engine was used. Application of positive matrix factorization to the dataset allowed the identification of nine factors relevant to the study area. This preliminary analysis permitted resolving two mineral factors. As a second step, a target rotation was implemented for transforming the mineral factors into experimentally characterized soil resuspension and industrial clay sources. In addition to improving the physical interpretation of these factors, the target rotation reduced the errors arising from the rotational freedom of the solution and the multicollinearity among sources. In this way, the main primary industrial emissions of PM in the zone were identified by this target factor analysis. A marked decrease was observed between 2002 and 2007 for the contributions of industrial sources coinciding with the implementation of mitigation measures in their processes. This study supports the utility of source apportionment methodologies for quantitatively evaluating the effectiveness of the abatement programs for air quality improvement. INTRODUCTIONIn addition to the particulate matter (PM) mass limit values, European Union (EU) standards (Directives 1999/30/CE, 2004/107/CE, and 2008/50/CE) set target values for arsenic (As; 6 ng/m 3 ), cadmium (Cd; 5 ng/ m 3 ), and nickel (Ni; 20 ng/m 3 ) in coarse PM (PM 10 ), and a limit value for lead (Pb; 500 ng/m 3 ) in PM 10 . These values are likely to be restrictive only for very specific regions with a high density of industries. This situation exists for the ceramic tile production area in Spain that produces approximately 17% of the worldwide supply of ceramic tiles. This industrial area includes more than 250 ceramic tile companies situated in 200 km 2 in the province of Castelló (eastern Spain) forming a so-called "industrial cluster." 1 As a consequence of this high concentration of ceramic industries that consume 12 Mt/yr of clay and 0.9 Mt/yr of ceramic frits, glazes, and pigments, 2 raw materials suppliers for these companies are also located in this area. There are two opencast clay quarries and around 20 companies producing frits and other glaze components within this ceramic production region.Ceramic frits are vitreous materials prepared by fusing a blend of crystalline raw materials (e.g., quartz, feldspars, zinc oxide [ZnO], zircon, borates, or lead oxides, in kilns operating at high temperature ...

The exposure to respirable crystalline silica (RCS), e.g. quartz, in industrial settings can induce silicosis and may cause tumours in chronic periods. Consequently, RCS in the form of quartz and cristobalite has been classified as human lung carcinogen category 1 by the International Agency for Research on Cancer in 1997, acknowledging differences in hazardous potential depending on source as well as chemical, thermal, and mechanical history. The physico-chemical determinants of quartz toxicity are well understood and are linked to density and abundance of surface silanol groups/radicals. Hence, poly-2-vinylpyridine-N-oxide and aluminium lactate, which effectively block highly reactive silanol groups at the quartz surface, have formerly been introduced as therapeutic approaches in the occupational field. In the traditional ceramics industry, quartz-containing raw materials are indispensable for the manufacturing process, and workers are potentially at risk of developing quartz-related lung diseases. Therefore, in the present study, two organosilanes, i.e. Dynasylan® PTMO and Dynasylan® SIVO 160, were tested as preventive, covalent quartz-coating agents to render ceramics production safer without loss in product quality. Coating effectiveness and coating stability (up to 1 week) in artificial alveolar and lysosomal fluids were first analysed in vitro, using the industrially relevant quartz Q1 as RCS model, quartz DQ12 as a positive control, primary rat alveolar macrophages as cellular model system (75 µg cm−2; 4 h of incubation ± aluminium lactate to verify quartz-related effects), and lactate dehydrogenase release and DNA strand break induction (alkaline comet assay) as biological endpoints. In vitro results with coated quartz were confirmed in a 90-day intratracheal instillation study in rats with inflammatory parameters as most relevant readouts. The results of the present study indicate that in particular Dynasylan® SIVO 160 (0.2% w/w of quartz) was able to effectively and stably block toxicity of biologically active quartz species without interfering with technical process quality of certain ceramic products. In conclusion, covalent organosilane coatings of quartz might represent a promising strategy to increase workers’ safety in the traditional ceramics industry.