Like crawl spaces within buildings, outdoor sites can also lead to dirt contamination from asbestos-containing materials. These sites include active and abandoned mines, mills, asbestos-product manufacturing facilities and other industrial factories that used or continue to use asbestos-containing materials. Some of these current locations accumulating outdoor asbestos contamination involve developing nations where asbestos use remains unregulated and the dangers of this mineral are unknown.
Recovery of asbestos-containing materials in these outdoor locations involves worker use of respirators and protective suits, though OSHA explains “that outdoor Class I work may be safely done without enclosures.” For Class I work performed outdoors, OSHA states that “employers do not need to erect critical barriers for outdoor work,” though abatement employers “must, at a minimum, use appropriate controls, including glove bag systems, where appropriate.” Sometimes heat stress can arise when abatement professionals work in hot climates, posing an additional concern. Therefore, a decontamination center located away from the abatement site may be required to allow employees time to rest, rehydrate and remove their respirators during their shifts without having to go through the entire decontamination process.
Outdoor Asbestos Remediation
Asbestos-containing materials may be found on the top of the earth, submerged just below the surface or purposely buried in the surrounding area. The outdoor remediation process generally involves wetting contaminated dirt, which prevents asbestos fibers from becoming airborne, and bagging it. It is then taken to a secure landfill site specifically designated for this material. Intact asbestos-containing components may also be buried in these designated landfills after being properly wrapped. Unlike crawl space soil contamination, outdoor asbestos abatement may involve significant digging to access buried materials.
However, the criteria for deciding how much soil must be removed from an area remains poorly established. Nevertheless, the use of visual inspection, which is used in crawl space cleaning, remains the best method of determining an outdoor area’s level of abatement success. This is especially true for developing nations where soil and air sampling and testing equipment is not available. After the completed process of asbestos containment, a layer of clean dirt will be placed over the remaining area. In some cases, a more complete barrier may be placed at the site, which might involve a layer of clean soil, followed by some kind of liner, followed by more soil. To ensure a site remains undisturbed, vegetation is often planted in the area, while a fence may also be constructed to ensure access is prevented.
Oberta, Andrew F. (2005). Asbestos Control: Surveys, Removal, and Management (2nd ed.). West Conshohocken, PA: ASTM International.