Naturally Occurring Asbestos Assessment, Exposure Prevention Strategies During Construction, and Capping for Long-Term Protection: a California, USA Example

The government of California, in the United States, has created requirements that are intended to protect the public from naturally occurring asbestos (NOA), partly due to the widespread areas in which asbestos minerals (including chrysotile and various amphiboles) are found within the state.Over ten years ago, the California Department of Toxic Substances Control Schools Unit published a thorough set of guidelines for addressing NOA at school construction sites.Their guidance document includes soil sampling procedures and frequency, recommended laboratory analytical testing methods, construction best practices to protect nearby residents from airborne exposures, capping methods to prevent re-exposure to students and public following the completion of the school improvement project, and follow-up procedures to ensure the capping method remains protective.Many of these best practices have been adapted into the construction process for commercial and residential buildings.  In California, protection of air is the regulated by Air Quality Management Districts, who regulate the generation of airborne asbestos as an air pollutant.Additionally, workers who are employed by a company, and working at a job site where asbestos is present, are protected by California Occupational Safety and Health (Cal-OSHA). Cal-OSHA requires varying protective measures to be implemented, based on the amount of asbestos that the worker is exposed to during their time at the construction project.This presentation will review the various regulations and best practices used in California by comparing a school construction project with a commercial office building.