What is the LOD of polycyclic aromatic hydrocarbons (PAHs)? what is it`s importance in estimation of the hazardous effect of exposure to PAHs?

LOD stands for limit of detection and it is expressed in concentration/content units. This analytical parameter is calculated for every compound belonging to PAHs, or other, individually, and for every analytical method, and for every sample type. `Group` LOD can not be calculated for all PAHs. This value denotes the lowest concentration that specific analytical methods can detect in specific sample, by applying specific sample preparation and specific analytical method. Specific compound can still be present in the sample but remain undetected, if its concentration in the sample is below LOD. LOD denotes that you can detect a compound within specific uncertainty range.

This parameter has nothing to do with estimation of hazardous effects of exposure. Other parameters are relevant here.