When should filter cartridges be changed while working with lead?

The most suitable time to change filter cartridges while working with lead is when performance is noticeably decreased. This option emphasizes the importance of monitoring the effectiveness of the respirator's filter. As lead exposure can be detrimental to health, it is vital to ensure that the respiratory protection equipment is functioning correctly.

When filter performance decreases, the efficiency of the filtration system is compromised, which can lead to inhalation of harmful lead dust particles. Timely replacement is crucial for maintaining protection levels and ensuring the safety of personnel working in environments where lead is present.

The other choices may not account for the actual measurement of cartridge effectiveness or can suggest unnecessary replacements. Regularly changing cartridges based solely on symptoms like difficulty breathing (as suggested by one of the choices) may not provide adequate safety if the filter might still be functional. Similarly, changing cartridges at the start of each work shift or every week may result in wasted resources if the filters are still effective, as filters can last longer depending on usage and exposure levels. Therefore, monitoring performance is the best approach for ensuring both safety and cost-effectiveness in lead abatement practices.