Event Recap: California Chapter of the International Society of Exposure Science
November 2, 2017
12:48 PM
Scientists from Exponent’s Health Sciences practice recently attended the inaugural meeting of the California Chapter of the International Society of Exposure Science, in Oakland, California. Ms. Alison Gauthier, Ms. Jamie Schenk, and Dr. Eric Winegar participated in the all-day meeting that consisted of presentations from a variety of regulatory and governmental representatives. The speakers discussed a range of exposure-related topics from various media, including air, water, and consumer products. An industry perspective was presented by Dr. Winegar that focused on Real-time Air Monitoring for Community Exposures, including a number of ambient air projects. Ms. Gauthier then followed-up with a discussion of a recent innovative occupational exposure study using direct mass-spectrometry.

Dr. Winegar's presentation focused on the value and approach to the collection of real-time measurements for assessing the impact of a source of contamination to a community. The value of real-time measurements was seen to be proportional to the decision-making need at hand, whether that is the more common health outcome or other potential impact. So, for a long-term exposure assessment, real-time measurements were of less value than for an acute exposure. In one highlighted project, the community was protected against sudden high emissions from remediation equipment at an oil-spill excavation site. A number of instruments were used to assess a set of targeted contaminants with known health thresholds. A system of Tiers was used to determine what actions to take, primarily to decrease the operation of the equipment. A second project was presented to show how hourly measurements allowed a previously unsuspected source to be the cause of suspected impact to a public soccer field. Instead of the nearby highway, it was shown that a municipal waste transfer station was producing a high impact during probable play times at the field. A warning was posted to provide guidance for those with respiratory concerns.

An additional project was discussed that was oriented towards monitoring for the community from the source perspective versus at the receptor. This site is a small oil field that has been in the public eye for years due to a series of high-profile odor complaints and calls for action against the operation. Following a number of regulatory and legal actions, the site has installed a continuous fence-line monitoring system that will guard against spurious emissions that may impact the community. A Tier system, similar to previous project, was developed using defensible health-agency derived exposure limits. This Tier system is designed to provide protection to both the community--for possible health-related impacts, and to the operation--for proactively determining possible impacts and taking corrective action.

In her presentation, Ms. Gauthier assessed the possible impact of a commercial solvent mixture used in floor tile installation. A direct mass spectrometer instrument was used to capture sub-second resolved concentrations of ethanol at the breathing zone of a volunteer. This data allowed the discrimination of various activities and the resulting exposure profile. Concurrent integrated samples were collected for off-site laboratory analysis, which showed good agreement with the averaged real-time data. The use of this instrumental approach showed the value of continuous species-specific measurements for a more complete understanding of the exposure dynamics.If you have any questions or would like additional information regarding their presentations, please contact Dr. Winegar and Ms. Gauthier.