EN
The concentrations of magnesium ions in the blood serum of individuals living in two different types of environments, an urban environment / Lublin / and a health resort (Nałęczów). Markedly low concentrations of magnesium were observed in the Lublin samples. Especially low mag nesium concentrations were observed in the samples taken from males. Large concentrations were observed in the Nałęczów samples. This study has shown that an urban environments markedly lowers the concentrations of magnesium in blood serum samples. This study shows the positive influence of the Nałęczów environment concerning coronary-arterial disseases.