In what situation should random sampling be employed for lead testing?

Random sampling should be employed for lead testing specifically in situations where specific housing history is unavailable. This approach allows for a more generalized assessment of lead presence, particularly in older buildings that may not have clear records of renovations or lead hazards. When housing history is unknown, random sampling helps in identifying the potential lead risks in a population, rather than relying solely on targeted sampling methods that might miss crucial instances of lead exposure.

In the absence of specific historical information, random sampling provides a statistically valid way of assessing lead hazards across a broader area, which could include various factors that contribute to lead exposure that may not be evident from historical data alone. This method thereby ensures a more comprehensive understanding of potential risks within the housing environment.

Contextually, other options do not necessitate random sampling. In newly constructed buildings, the assumption is that they are built to current safety standards, which minimizes concerns about lead. When dealing with fewer than 50 units, targeted sampling strategies can often be more effective and efficient. Testing single-family homes typically allows for more direct assessments without needing random sampling to gather sufficient data, especially when other inspection methods can be used effectively.