I referenced several OSHA and NIOSH methods throughout the project, including NIOSH 2549, 1300, and 1501 for volatile organic compounds (VOCs); NIOSH 2527 for nitromethane; and OSHA VI-6 for hydrogen peroxide. In addition, I referenced the German Research Foundation (DFG) and Institute for Occupational Safety and Health of the German Social Accident Insurance (IFA) method 8943 for hydrogen peroxide. Certain methods proved to be obsolete for our needs due to outdated technology. In some cases, IH methods did not provide a limit of detection low enough to successfully sample in our different project scenarios. For example, OSHA Method ID-126-SG, one of two OSHA methods for hydrogen peroxide, recommends analysis via mercury electrode. This method was not an option for us because mercury electrodes are banned throughout Europe. OSHA Method VI-6 was still available to us, but only partially validated. This left us searching for new methods in the literature. Some of our project scenarios were more in line with environmental levels, which also have methods available. But the recommended sampling times and flow rates did not agree with our timeline or scenario. For example, the levels of VOCs we were looking for were lower than typical occupational exposure limits, and our desired sampling times were much shorter than environmental sampling times. We needed to adapt these methods to our project. And so, in a quest to find the optimal flow rate for our purposes in one sampling campaign, my colleague Carlotta Ferrari was able to design our experiment using chemometrics. Chemometrics uses mathematical and statistical methods to extract information by analyzing chemical data and optimize procedures or experimental designs. It can also be used to merge data from many different sources. This approach provided the most favorable number of trials needed in which configurations to get the most reliable results in our study. Development and improvement of sampling and analytical methods is a common goal for both the IH and security fields. In addition to referencing many IH methods, we worked to improve and optimize methods for our specific interests and for the IH field in general. The BONAS and IST groups worked together to adapt and develop two new analytical techniques for identifying hydrogen peroxide during the bomb-making process and, consequently, in the workplace. We used these methods for sampling and analysis during the project. Although the exposure limit for hydrogen peroxide is not extremely low, enhancing the method now allows for short-term sampling. This proved beneficial: new literature suggests a short-term exposure limit (STEL) for this substance, which would not be possible to determine using the current recommended method. In short, both IH and security will benefit from improving the method, even though the side project stemmed from the separate needs of each field. Another area where IH and security overlap is sensor technology. Many sensors are developed to identify a substance in a known amount or controlled environment, and difficulties arise when considering how to capture a sample and identify it in a real-world environment. For example, some substances can only be measured as a liquid or solid due to limitations of the technology, or the sampling unit within a sensor isn’t optimized for what the researcher wants to collect. One researcher on the BONAS project was surprised to find that his sampling unit contained media that is very common in the IH field. The IH on the IST team and I were able to clear up some of his questions about the optimal use of the media and other specifications, given our background and expertise in sampling. Understanding and identifying peak exposures is imperative for preventing both the formation of explosives and adverse health effects to workers. Several activities can occur during the bomb-making process that provide optimal opportunities for authorities to discover the threat. Bomb making involves measuring, pouring, and mixing many different substances of interest. The sensors developed during the BONAS project are intended to alert authorities to heightened levels of these substances. Similarly, we are concerned about activities in the workplace where peak exposures can occur to a worker. However, it is often difficult to capture the profile of a peak exposure when utilizing typical air sampling and analytical methods. For this reason, adapting equipment from other fields could certainly be of interest. The ability to identify peak exposures individually or via continuous monitoring already exists for multiple chemicals of interest. But new techniques developed by the BONAS and IST groups allow us to conduct reliable short-term sampling and continuous monitoring in the work environment, relaying real-time results. These new methods are the first available for short-term sampling or continuous monitoring for hydrogen peroxide. One new technique uses a method of analysis referred to as “FOX.” It uses a portable photonic detection instrument developed to continuously measure ferrous oxidation in the presence of xylenol orange. This in turns gives us the potential for oxidative stress present in the environment. The other technique developed is a chemiluminescent technique, capable of analyzing directly on-site as well. The outcome of our work shows us that opportunities exist for continuous on-site monitoring via a portable FOX set-up, or simple on-site analysis using a portable luminometer.

Sensing technology developed for security purposes could potentially be applied in the workplace. Perhaps several of the sensors we used could be implemented for occupational or environmental use. The sensors developed and enhanced throughout the project include technologies such as light detection and ranging (LIDAR)/differential absorption LIDAR detection system (DIAL) sensor; quartz-enhanced photo-acoustic spectroscopy sensor (QEPAS); surface-enhanced Raman spectroscopy sensor (SERS); immunosensors; and electrochemical sensors. A basic illustration of how these sensors can be deployed to identify bomb-making activities is available on the Project BONAS . Another opportunity is the further development of optimal exposure assessment strategies, potentially bridging the gap between pharmacokinetic modeling, biomarkers, and actual adverse health effects to the worker. Merging IH with security or other fields could result in many beneficial opportunities. Take our project, for example: our team developed and completed work on improved and novel methods for hygienists in less than a year. Imagine the numerous possibilities that would come with collaboration over time. Collaborating with physicists, chemists, and professionals in other fields is important to advancing industrial hygiene. A Google search or literature review can unearth the “latest” technology, but on many occasions, the technology is already developed for another purpose by the time of publication or isn’t very novel anymore. Industrial hygienists who work on interdisciplinary teams can influence the purpose and use of technology for our specific field early on. I often collaborated with researchers on my team throughout our project to explain what IHs look for in an occupational setting, or to discuss the concerns and realities of certain equipment. In turn, they shared their current capabilities and ideas so that we could decide together on developments that would suit each of our needs. Here’s one example of something we discussed as a team: if analysis can take place on site but requires the use of a liquid media, we may want to adapt the method so that it’s not necessary to require the worker to wear an impinger while still allowing analysis to be completed on site. Researchers may not have experienced impingers in the field on a working body and may not find this to be problematic. But as IHs, we know that this is not the optimal experience for us, the worker, or the equipment. Industrial hygienists are well aware of the benefits of ideas that emerge from working on interdisciplinary teams. This teamwork is vital for the growth and evolution of the IH field, as well as other professions. Though many companies are dedicated to advancing IH equipment, and technological progress is made all the time, we should continue to work toward building equipment and developing methods to fit our needs rather than adapting existing tools for our purposes. Interdisciplinary teamwork in particular provides a way for people from different fields to conquer their overlapping needs and contribute to their professions—together.