Attention is paid to conditions and the history of integration of chemical elements in biogenic elements and their role in chemistry teaching. A part of results of the research is shown, which was made among chemistry teachers and students at primary and secondary schools. Inclusion of findings about the impact of oxygen radicals on human body, a topic often mentioned in media, in chemistry teaching plans for secondary schools is suggested. A brief survey of sources, direct and indirect effects, and degradation of oxygen radicals in human body is given.