A simple method based on ICP-MS for estimation of background levels of arsenic, cadmium, copper, manganese, nickel, lead, and selenium in blood of the Brazilian population - Nunes, Juliana A; Batista, Bruno L.; Rodrigues, Jairo Lisboa; Caldas, Naise M.; Neto, José A. G.; Barbosa Júnior, Fernando (Journal of Toxicology and Environmental Health, Part A, 2010)