In a Federal Register notice on Sept. 22, the Centers for Disease Control & Prevention (CDC) and the National Institute for Occupational Safety & Health (NIOSH) announced plans for a new exposure assessment and epidemiological study of U.S. workers that are exposed to carbon nanotubes and nanofibers. The agencies are taking public comment on the study through November.
According to the notice, NIOSH will conduct an industry-wide exposure assessment to evaluate worker exposure to the nanomaterials and develop and refine measurement methods for carbon nanotubes and nanofibers, followed by a “cross-sectional study” relating the best exposure metrics to early pulmonary or cardiovascular health effects. These phases will be followed with an “industry-wide study of the association between exposure and health effects,” including medical examinations of workers focused on a number of biomarkers indicating pulmonary fibrosis, heart disease and genetic damage.
The study will include a questionnaire that seeks: “to determine whether study participants have any contraindications for certain medical procedures to be conducted (spirometry and sputum induction); to assist in interpretation of the biomarker results; and to inquire about current and past exposure to [carbon nanotubes], [carbon nanofibers], and other chemicals, dusts, and fumes,” the notice says.
The FR notice says there has been little study of the health impacts of workplace exposure to carbon nanotubes and nanofibers. “At present, because of the newness of the technology, much of the occupational exposure to engineered nanomaterials occurs at the research and development or pilot scale,” the notice says. “There have been few reliable surveys of the size of the workforce exposed to nanomaterials. Health effects from exposure to nanomaterials are uncertain, but may be more severe than from larger-sized particles of the same material.”