title: Characterization of manganese-bearing particles in the vicinities of a manganese alloy plant.
abstract: Numerous studies have associated air manganese (Mn) exposure with negative health effects, primarily neurotoxic disorders. Despite there is not a specific European regulation, institutions such as the World Health Organization (WHO) have proposed an annual average guideline value of 150 ng/m3. Bioaccessibility and toxicity mechanisms of Mn remain unclear, however it is generally agreed that adverse health effects are strongly linked to particle size and morphology, chemical composition and oxidation state. This study aims to deepen the understanding of the physico-chemical characteristics of PM10and deposition samples collected in an urban area in the proximities of a ferromanganese alloy plant. Total Mn content was determined by ICP-MS after a microwave-assisted acid digestion. The size, morphology and chemical composition of individual particles were studied by SEM-EDX. XRD was used to identify the major crystalline phases. Most of the particles observed by SEM-EDX contain Mn. 60% of Mn-PM10particles were spheres of small size and were attributed to condensation processes at the smelting unit. Mn-bearing particles present in deposition were characterized by irregular shapes and bigger sizes, most of them consisting of SiMn slags and Mn ores and alloys, and attributed to diffuse emissions from raw material and product handling and processing. Due to the differences in the characteristics of Mn-bearing particles found in the different matrices, further studies on the potential toxicity and health effects of these particles should be done, especially in relation with the small and spherical particles present in PM10, which are expected to be more problematic.
authors.affiliation: Dpto. de Ingenierías Química y Biomolecular, Universidad de Cantabria, Avda. Los Castros s/n, 39005 Santander, Cantabria, Spain. Electronic address: ana.hernandez@unican.es.
authors.forename: Ana
authors.initials: A
authors.lastname: Hernández-Pellón
authors.affiliation: Dpto. de Ingenierías Química y Biomolecular, Universidad de Cantabria, Avda. Los Castros s/n, 39005 Santander, Cantabria, Spain.
authors.forename: Ignacio
authors.initials: I
authors.lastname: Fernández-Olmo
authors.affiliation: Unité de Chimie Environnementale et Interactions sur le Vivant (UCEIV, EA4492), Université du Littoral Côte d'Opale, 145 avenue Maurice Schumann, 59140 Dunkerque, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Ledoux
authors.affiliation: Laboratoire d'Océanologie et de Géosciences (LOG, CNRS UMR8187), Université du Littoral Côte d'Opale, Wimereux, France.
authors.forename: Lucie
authors.initials: L
authors.lastname: Courcot
authors.affiliation: Unité de Chimie Environnementale et Interactions sur le Vivant (UCEIV, EA4492), Université du Littoral Côte d'Opale, 145 avenue Maurice Schumann, 59140 Dunkerque, France.
authors.forename: Dominique
authors.initials: D
authors.lastname: Courcot
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D000497:Alloys; D007501:Iron / Q000737:chemistry; D008345:Manganese / Q000032:analysis* / Q000737:chemistry; D008669:Metallurgy; D010316:Particle Size; D052638:Particulate Matter / Q000032:analysis*; D013030:Spain
chemical_list: D000393:Air Pollutants; D000497:Alloys; D052638:Particulate Matter; C083456:ferro-manganese alloy; D008345:Manganese; D007501:Iron
keywords: Deposition; Ferroalloy plant; Manganese; PM(10); SEM-EDX; XRD