which exceed the assigned protection factor for the typical type of respirator (half-face elastomeric or filtering face-piece) used by the workers at the sites visited. As part of the study, NIOSH identified seven primary points of dust generation and developed control recommendations that included both passive and active controls. The NIOSH team also described nine possible interventions to control dust, including
Mr. Esswein reiterated that NIOSH determined that respirable crystalline silica is a significant occupational health hazard associated with hydraulic fracturing; diesel particulate is also a likely occupational health hazard.
Following the presentation from Mr. Esswein, Roundtable members started the discussion by asking about silica exposures at mines during the loading and unloading of trucks. Mr. Esswein noted that NIOSH’s assessment was limited to evaluating exposures only at oil and gas sites, not any further upstream. Nsedu Witherspoon inquired about exposures to pregnant workers and Mr. Esswein replied that he only saw two female oil and gas workers, and the NIOSH team did not evaluate their exposures. Bernard Goldstein asked about a 2008 article showing an increase in injuries per shale gas well and asked about the status of injuries. Dr. Goldstein went on to comment on integrating workers’ health and
2 Prevention through Design is a NIOSH-led effort to address occupational safety and health needs in the design process to prevent or minimize the workrelated hazards and risks (http://www.cdc.gov/niosh/topics/ptd [accessed May 30, 2013]).