Assessment of knowledge and awareness of heavy metals among secondary school students in the vicinity of Mkwawa University College of Education, Tanzania

Heavy metals pose significant environmental and health risks, yet not much is known about awareness and understanding of these risks in low- and middle-income settings. This study assessed knowledge and awareness of heavy metals among 870 secondary school students from five schools in the vicinity of Mkwawa University College of Education, Tanzania. Data were collected using a semi-structured questionnaire administered in English. The collected data were subjected to descriptive statistics, chi-square tests, and correlation analyses. Findings show that only 13.5% correctly identified mercury, and misconceptions were frequent. As for the awareness of sources of heavy metals, the most recognized sources include electronic waste (17.4%) and soil/agricultural products (15.6%). Health risk awareness was limited as only 43.2% of the respondents recognized adverse effects, primarily cancer and kidney damage. Preventive knowledge was moderate, while also many students lacked accurate understanding of exposure reduction measures. Significant associations were observed between knowledge or decision responses and age, gender, and class level, while school affiliation had no effect. The findings reveal a gap between students’ self-perceived knowledge and demonstrated understanding, highlighting widespread misconceptions. These results underscore the need for context-sensitive, participatory, and inquiry-based environmental health education to improve conceptual understanding, to correct misconceptions, and promote protective behaviors.