What must be monitored over time during medical surveillance?

Monitoring changes in blood lead levels over time during medical surveillance is essential for ensuring the health and safety of individuals who may be exposed to lead in their work environment. This practice is critical because lead exposure can have serious health consequences, including neurological and physiological damage. By regularly checking blood lead levels, supervisors and medical professionals can track any increases that may indicate overexposure to lead, allowing for timely interventions to prevent more serious health issues.

In contrast, options such as monitoring daily work hours, employee training sessions, or weekly employee satisfaction do not focus directly on the health risks associated with lead exposure and are not typically part of medical surveillance protocols designed specifically for lead. These other factors may be important for overall workplace management but do not address the specific health implications related to lead exposure and the need for ongoing health monitoring.