How to Interpret Lead Test Kit Results (Screening vs Laboratory)

Understanding Lead Test Results

Interpreting lead test results requires understanding the type of test used and its purpose. Screening tests and laboratory tests serve different roles in lead risk assessment.

Screening Test Results

Screening tests typically provide:

• Positive or negative indicators
• Threshold-based responses
• Qualitative or semi-quantitative results

A positive screening result suggests that lead may be present at or above a meaningful level. It does not indicate exact concentration or long-term exposure.

Laboratory Test Results

Laboratory tests provide:

• Quantitative measurements
• Specific concentration values
• Higher analytical precision

These results are often used for regulatory compliance, documentation, or detailed risk assessment.

Why Results May Differ

Differences between screening and laboratory results can occur due to:

• Sample timing
• Water stagnation
• Sampling location
• Analytical sensitivity

Both types of results are valid within their intended use.

Deciding What to Do Next

After a positive screening result, next steps may include:

• Confirmatory laboratory testing
• Plumbing evaluation
• Filtration installation
• Retesting after mitigation

Negative results may still warrant periodic monitoring in higher-risk homes.

Screening and laboratory tests complement each other. Screening tests provide rapid insight, while laboratory tests provide precision. Used together, they support informed decision-making.