The National Institute for Occupational Safety and Health (NIOSH) recommended practices to prevent the risk of disease among workers who are exposed on the job to biosolids used to fertilize agricultural lands or mine reclamation sites.
Biosolids are sewage sludge that has been treated to significantly reduce or eliminate concentrations of bacteria, viruses or other microorganisms.
At a level of treatment know as "Class B," some microorganisms may still be present.
Under environmental rules, access for the general pubic to areas where Class B biosolids have been applied is restricted for varying time periods up to one year, allowing time for remaining microorganisms to die off naturally.
However, workers may be occupationally exposed in handling, applying or disturbing the material during this restricted period.
"Workers are the individuals most likely to be exposed to biosolids, but practical steps can be taken to limit exposures and prevent the possible risk of disease transmission," said NIOSH Director Linda Rosenstock. "In the absence of definitive information about the extent of risk to workers, our recommendations are based on good public practice."
NIOSH recommends that:
- Engineering controls and work practices should be used as first measures to prevent worker exposure to Class B biosolids during and after field applications.
- If engineering controls are not feasible at a Class B biosolid site, or while engineering controls are being installed or maintained, personal protective equipment for workers should be provided and required.
- Hand washing stations with clean water and mild soap should be provided, and cabs on heavy equipment should be cleaned of residual mud or dust after each use.
- Employers should provide periodic training about standard hygiene practices on the job.
The recommendations are made in the NIOSH Hazard ID titled "Workers Exposed to Class B Biosolids During and After Field Application."
It is available on the NIOSH Web site at www.cdc.gov/niosh/hidlist.html.
by Virginia Sutcliffe