these may be based on age sex or income level or groups of risks based on people s environment such as the roadway home workplace or residential area thus selected individuals or groups of individuals exposed to similar risks are targeted by preventive programmes to help them to avoid these risks or to detect specific conditions at an early stage although some risks are related to specific health conditions the same or similar types of risks may lead to various health conditions thus overlaps may exist in the coverage of programmes depending on their structure at the national level