Should control measures be based on air measurements or biological/biological effect monitoring?

The setting of, and the review of, exposure limits takes into account toxicological, occupational hygiene and epidemiological data. The COSHH Regulations 1994 define a hierarchical approach to controlling workplace exposures with a particular emphasis on the measurement and control of airborne substances. Absorption via the lungs is considered the most important route of entry in the workplace, however, percutaneous absorption must not be overlooked. Biomarkers are used extensively in the surveillance of workers' exposure to metals and organic chemicals. In addition, Genetic polymorphism for xenobiotic metabolism has been widely studied. The selection, validation and application of any biomarker is a complicated process and requires careful consideration prior to any application.