Oxidative Potential Sensitivity to Metals, Br, P, S, and Se in PM10 Samples: New Insights from a Monitoring Campaign in Southeastern Italy

Abstract

Different analytical techniques were used in this work to investigate the relationships between oxidative potential (OP) and metal, Br, P, S, and Se concentration in PM10 samples. Dithiothreitol and ascorbic acid acellular assays were used to determine the oxidative potential (OP) in PM10 samples. The particle-induced X-ray emission technique was used to estimate the mass concentration of specific chemical elements. PM10 samples were collected in Lecce, a coastal site of the Central Mediterranean away from large sources of local pollution. Both winter and spring samples were analyzed to study the seasonal dependence of the relationships between OP values and chemical element concentrations. The Redundancy Discriminant Analysis (RDA) was applied to (volume- and mass-normalized) OP values as response variables and metal, Br, P, S, and Se concentrations as explanatory variables. RDA triplots allowed to visualize the main relationships between PM10 OP values and corresponding chemical element concentrations. Spearman correlation coefficients were also used to investigate the relationships between OP values and metal, Br, P, S, and Se concentrations, besides comparing RDA outcomes. The integrated approach based on two different techniques allowed to better highlight the potentially harmful effects associated with specific metals and other chemical elements in PM10 samples.

Keywords

• PM chemical composition
• air pollution
• air quality observations
• seasonal variations
• oxidative potential
• metals