2. Materials and methods
The study aims to investigate the impact of changes in cadmium
and lead pollution levels on the incidence of cancer reported in
children. A list of carcinogenic heavy metals that indicate a strong
relationship between cancer incidences and cadmium, and a potential
risk connected with lead, has been drawn up in Poland (Ordinance of
the Minister of Environment, 2004) and allows for analysis of cancer
incidence in children.