LAX ABOUT NANOMATERIAL HANDLING EXPOSURE: Many protective measures
are not being utilized, survey shows
A
S MANY AS one-quarter of researchers han-
dling nanomaterials do not use any lab protection measures, such as fume hoods, and half do not use masks or respirators to prevent inhalation of particles, according to an international survey of research laboratories by a team of Spanish researchers (Nat. Nanotechnol., DOI: 10.1038/nnano.2010.1). “We don’t know a lot about the consequences of long-term exposure to nanoparticles,” comments Kristen Kulinowski, director of external affairs at Rice University’s Center for Biological & Environmental Nanotechnology and director of the International Council on Nanotechnology. Consequently, much of the available guidance for handling nanomaterials safely focuses on minimizing exposure. “It sounds like that message has not gotten down to the research community,” Kulinowski says. The survey team, led by Jesus Santamaria of the Nanoscience Institute of Aragon at the University of Zaragoza, used a Web of Science literature search for keywords such as “nanoparticle” and “nanotube” to identify researchers working with nanomaterials. They contacted 2,300 researchers, and 240 completed the survey. Of those, 95% were from universities or other institutional research labs. About 35% of the respondents were laboratory principal investigators. The rest were other researchers in the groups. The survey found that among researchers who were
aware that their materials could become airborne, 21% used “no special protection” in the lab and 30% used no personal protective equipment when handling nanomaterials. The survey results are not surprising to representatives of the National Institute for Occupational Safety & Health, who have observed similar results in field studies they conduct to evaluate methods to determine exposure to airborne particles, says Charles L. Geraci Jr., coordinator of NIOSH’s Nanotechnology Research Center. NIOSH has developed a two-pronged approach for assessing nanoparticle exposure that includes both general particle counters and filter-based sampling coupled with chemical and microscopic analysis to determine the identity of particles (J. Occup. Environ. Hygiene, DOI: 10.1080/15459620903476355). In field studies, NIOSH researchers found that nanomaterials can become airborne during tasks such as cleaning of reactors, weighing, and sonicating. Nanomaterials are emitted in the form of agglomerates and clusters rather than as individual fibers or spherical particles (J. Occup. Environ. Hygiene, DOI: 10.1080/15459620903508066). Andrew D. Maynard, chief science adviser at the nonprofit Project on Emerging Nanotechnologies, questions the results of the Spanish survey, saying that the questions were poorly worded and contained confusing language: A “mouth mask without filters,” for example, could be taken to be a simple surgical mask or one that is designed to be a particulate filter, such as the N95 mask found by NIOSH to be effective against nanoparticulate aerosols. But the confusion, Maynard adds, still points to a need for better understanding, awareness, and implementation of safe-handling protocols for nanomaterials.—
J. OCCUP. ENVIRON. HYGIENE
NEWS OF THE WEEK
TEM image of a filter shows multiwalled carbon nanotubes that were emitted when the material was weighed in a hood with no ventilation.
JYLLIAN KEMSLEY
NATURAL PRODUCTS New evidence confirms suspicion that plants can also make progesterone
SHUTTERSTOCK
For the first time, researchers have obtained rigorous evidence that progesterone, a mammalian steroid hormone, is found in a plant (J. Nat. Prod., DOI: 10.1021/ np9007415). Many research groups have hinted at the presence O of progesterone H O
H
H
Walnut tree leaves, in which researchers have found progesterone.
in plants—the compound can be made from precursors found in plants such as the Mexican yam. While searching for cytotoxic entities in walnut tree leaves, Guido F. Pauli of the University of Illinois, Chicago, and colleagues isolated small quantities of progesterone and confirmed the hormone’s presence by a combination of mass spectrometry and nuclear magnetic resonance techniques. In another plant, the team discovered novel sulfates of progesterone-like compounds. “This raises fundamental questions about steroid biosynthesis—can all plants make progesterone?” Pauli asks. In mammals, progesterone has several roles, such
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as preparing the uterine lining for a potential pregnancy, but progesterone’s biochemical role in plants is not clear, which warrants further research, he says. “Although we may have thought we knew that plants contained progesterone, Pauli and colleagues have definitively proven this to be the case,” says Charles L. Cantrell, a research chemist at the U.S. Department of Agriculture. “I consider this to be a major contribution to our knowledge of plant secondary metabolite biosynthesis,” says David S. Seigler, who studies plant biology at the University of Illinois, Urbana-Champaign.—CARMEN DRAHL
