TEH Exposure Data Sources
The practice of IH uses risk assessments and specialized surveys to collect, analyze, and apply exposure data to one individual or a group of individuals deemed to be an SEG. The resource cost of this sampling can be significant. The cost of time must be considered. Planning a sampling event, preparing instrumentation, collecting data and observing the work, and then posting the results of the sampling all take time. The second cost is the monetary cost; sampling equipment and the analysis costs can both be expensive. Because of these costs, limited numbers of samples are often collected.
The following is a practical example. A factory employs 200 workers located throughout its facility, and all have some variations in their exposure to noise. The IH office has two kits of five dosimeters for a total of ten. Noise changes from day to day as plant operations vary with daily production requirements, and a noise meter indicates levels above 85 decibels А-weighted routinely in the facility. Given this scenario, an IH would look for SEGs and would likely be sampling for many weeks and running from worker to worker documenting the work being done in a sample narrative. The lowest resource cost possible would consider the 100 workers a single SEG, and the IH would sample a minimum of ten workers for 3-Ю workdays. The possibility that one SEG would adequately represent the exposures for all these workers would be highly unlikely, and for every increase in SEG, the cost in time increases. Adding more dosimeters to reduce time would be difficult due to their cost.
Under TEH, ideally, each worker not only would have his or her own exposure monitor, but when needed, exposures from non-work periods could also be measured. Obviously, new measurement methods are needed to make this possible. These methods are coming into the IHs sphere, and the next few sections will highlight examples of some of the current measurement methods. Later chapters in this volume will cover developments in low-cost, easy-to-use, and multi-analyte sensors to support more types of exposure monitoring and include each person individually.
Environmental and Community Health
The IH and EHS can collect some environmental exposure data in and around a traditional workplace to determine the exposure potential of the workplace apart from the operational or industrial exposures. The collection could be soil, dust, ambient air, and water samples. These samples would not represent personalized exposure data on their own; they would alert the IH to the possibility that personal sampling might be needed or that some other exposure management decisions might be necessary to reduce actual personal exposure. Much of this data is also available through monitoring and recordkeeping required under present environmental regulations. Particulate matter 10 (PM 10) and PM2.5 with diameters that are generally 10 and 2.5 micrometers and smaller are collected regularly at the county and city levels (USEPA 2019) and chemical exposures through reporting under the Emergency Planning and Community Right-to-Know Act (EPCRA), specifically in sections 304 and 313. Section 304 primarily covers required reporting of hazardous substances from emergency releases. The greatest value for informing a user of TEH is the “Continuous Release Reporting” requirements where releases that are regular and ongoing are reported. Section 313 covers the Toxic Release Inventory (TRI), and facilities must report annually on more than 600 chemicals that are manufactured or used above a threshold quantity. This reporting includes how the material is released and is useful in knowing which chemicals may be present from releases in and around the population needing to have environmental exposures tabulated (USEPA 2018). The specific data files from 1987 through 2018 can be accessed at https://www.epa.gov/ toxics-release-inventory-tri-program/tri-basic-data-files-calendar-years-1987-2018, and in these reports, the specific chemicals are listed with the address of the facility. The release information is sufficiently detailed to allow IHs to determine whether or not there could be some significant impact to the location or facility being evaluated by them (USEPA 2019).
Personalized sensors discussed in the next section have the advantage of being used by numerous users across an area. This data is being collected in many areas and can be available to use with the individual identification data removed, and the remaining information can be used to create exposure zones which are area environmental sensors. This can be especially advantageous in cities and towns where a small but significant portion of the community has chosen to use a sensor platform. Examples of these present usages of personalized sensors are air sampling devices provided to asthma patients for personalized air quality measurements (Patringenaru 2012) and the US Air Force study on noise monitoring (International 2017).
Personal Environmental Exposure Sensors and the Internet of Things
Many exciting opportunities become available since the TEH framework allows the IH and EHS to use a host of sensors to obtain information. This volume has a chapter that provides a detailed overview of the sensor technologies that are emerging and the challenges that must be overcome to fully incorporate these sensors into healthy lifestyle practices. It is likely that workers are bringing their own sensors into the workplace and using them in their homes already, and the IHs can capitalize on these personally owned sensors to increase the amount of exposure data available to them.
Once methods are developed and standardized to meet established testing and accuracy, these personal sensors can be utilized for the collection of data which can become part of the official exposure record. In these cases, the personal sensors are often smaller and cheaper to employ than versions of the IH standard measurement equipment. Early types of sensors that fall into this lower cost and easy-to-employ class are passive monitors that rely on diffusion sampling. Newer and emerging technologies such as the silicone bands presented later in this volume take the diffusion sampler to the next level, increasing the number of analytes collected in a single sample significantly and reducing the cost to the sampler. They also reduce the time costs for the IH as they are very easy to employ, and the wearer can change to a new band at intervals which could be relevant such as work hours and non-work hours.
The advent of smart mobile devices has created other advantages that can be utilized by the IH and EHS. The personalized sensor can always be with the individual, provide real-time updates, and identify exposure location. The smart mobile device replaces the traditional monitor in every aspect except the sensor itself. This is possible because the mobile device serves as the processing power, contains the user interface, and has a custom-developed application available through the mobile device’s application store. Amazingly, these high-tech devices even have some sensors onboard and can be used for measuring acceleration, vibration, or noise. Other sensors do require an add-on attachment which the IH or EHS must provide, but in effect, the individual being measured will have purchased the logic system portion of the hardware. The IH, EHS, or other occupational health professionals, such as a physician, can provide the sensor attachment, and with appropriate permissions and the application using data protection measures, personal data can arrive directly to the IH practice in real time. If the application has the ability to deliver data in real time, the IH will be able to identify when an event of significant exposure is occurring, notify the device user of the exposure, and, with input from the user, determine what activity triggered the exposure event. This greatly enhances the interpretation of the data for the IH and informs the person of specific activities and times which have a higher exposure potential.
As mentioned earlier, a number of sensors are coming to market which are being designed with a cost low enough to allow the practicing IH to have enough sensors to measure every individual. With increasing frequency, individuals are actually purchasing the entire sensor package to meet their own desire to have the information, and often these sensors come with multiple capabilities that the purchaser may not even want or use. For example, the Apple Watch Series 4 and 5 have integrated into their hardware and its operating system (version 6) an option to have continuous noise monitoring (Apple 2019). The watch continually monitors sounds in the environment and can display a real-time sound level meter. When the ambient noise exceeds a threshold (user selected between 80 and 100 dBA in 5 dBA increments), a warning is displayed, and the wearer is informed of an environment which could be hazardous. Each level is accompanied by the recommended limit in accordance with the World Health Organization’s recommendation. There is not an integrating function, so it is not acting as a dosimeter, but an IH could ask a worker to set the limit at a desired setting, say 85 dBA, and ask him or her to report if the watch warned of a noisy environment. The data is collected in the health application and displays data every 2 minutes. Additionally, it has filters to show specific notifications of high noise periods. The data is sufficient for the IH to know whether or not a worker is experiencing quiet periods when not working and for how long. It will also allow the IH to learn if his worker experiences hazardous noise when not at work and the frequency of exposure. This information can be used to ensure that appropriate additional controls are implemented to keep exposure levels below the hazardous thresholds.