What is the threshold for an XRF reading that indicates a positive result?

The threshold for an XRF (X-ray fluorescence) reading that indicates a positive result is set at equal to or greater than the standard. This means that when an XRF reading meets or exceeds the established criteria for lead concentration, it is interpreted as confirming the presence of lead at levels that pose a risk, necessitating further action such as remediation or risk assessment.

Understanding lead exposure risk is crucial, particularly in residential environments. The established standards are based on regulatory guidance that ensures the safety of individuals, particularly children who are more vulnerable to lead exposure. This standard serves as a benchmark for determining the necessity of interventions to reduce lead hazards in the environment.

The other thresholds provided do not correctly align with the accepted standards for lead detection. A reading less than 0.5 mg/cm² would not be indicative of a significant lead hazard, while thresholds that are too high would fail to identify potential risks at lower concentrations. Thus, the correct threshold reflects a balance between safety and practical risk management in environments where lead might be present.