What is the MAAL when measured via Transmission Electron Microscopy (TEM)?

The MAAL, or Minimum Analytical Action Level, specifically defined for the monitoring of asbestos in the air via Transmission Electron Microscopy (TEM), is set at 70 structures per square millimeter. This benchmark is critical for assessing potential exposure to asbestos fibers and ensuring compliance with safety regulations, as it helps determine whether air quality is within safe limits.

Using TEM, which is a highly sensitive technique for detecting and quantifying asbestos structures, allows for accurate measurements of airborne asbestos. The value of 70 structures per square millimeter provides a clear threshold; if the observed concentration of asbestos exceeds this figure, it triggers the need for further action or remediation.

Other options provide different figures, but they do not align with the established regulatory standard for MAAL measurement via TEM. Thus, the option stating 70 structures per square millimeter is recognized as the correct standard for industrial and occupational health compliance concerning asbestos exposure assessment.