Embedded systems and the Internet of Things: Can low-cost gas sensors be used in risk assessment of occupational exposure?

History and investigation of the chemical odors and explosion in the University Avenue sanitary sewer

During the summer of 2022, a fire and explosion occurred in a sanitary sewer tunnel adjacent to the University of Minnesota Twin Cities campus, propelling utility maintenance covers several meters into the air and jeopardizing the safety of the public and emergency responders. The investigation into the explosion highlighted the complex variables involved in the response to sanitary sewer events. This case study outlines current approaches and proposes recommendations for agencies to be better prepared to prevent, detect, and respond to sewer-related incidents in the future. Our recommendations include the following: (1) proactive use of remote volatile organic compound (VOC) and lower explosive limit (LEL) monitoring in sanitary sewer tunnels, especially downstream of waste discharge sites; (2) incident responders should have access to instruments that measure oxygen, LEL, VOC concentration, carbon monoxide, and hydrogen sulfide; (3) better characterization of the relationship between sewer pressurization, elevation profiles, and vapor movement; (4) verification processes for oil/water separators used by industrial facilities discharging into the sanitary sewer system; (5) installation of ventilated or anchored pressure relief utility maintenance covers where allowed by code; and (6) building maintenance protocols that include regular drain flushing to keep drain traps filled. These measures are recommended to protect infrastructure and the health and safety of the public and the responders.

Intra-workday fluctuations of airborne contaminant concentration and the time-weighted average

Air contaminant concentrations vary between and within workdays and are often measured across a workday by passing a known air volume through a collection device. Laboratory analysis determines the contaminant mass trapped, providing a time-weighted average air concentration (C_TWA). This approach was driven by the best technologies available as exposure measurement processes developed and accuracy and measurement precision were sought. However, all integrated concentration•time (C•t) values determining C_TWA are equally weighted in assessing exposures, intra-workday concentration variability is unknown, and results are available days later. At times inappropriately, an occupational exposure limit (OEL) expressed as a C_TWA also requires equal weighting of all C•t values across an exposure period following concepts of Haber's law. Continuous monitoring (real-time detection) informs both the C_TWA and the variability of C during sampling, which are needed for stressors where a ceiling or peak OEL exists, for dangerous exposures to permanent gas-type contaminants, and for immediately dangerous to life or health (IDLH) conditions. Selective and accurate real-time detection instruments are not available for all air contaminants, but exposure magnitude information may be provided. The large amounts of data from continuous monitoring and the ability to correlate exposure maxima to specific tasks are also important. An exposure assessment role exists for selective and nonselective monitors, and in some cases, similar accuracy and precision are provided compared to laboratory analyses. Continuous monitoring may be of value when the alternative is the collection of a few C_TWA data points. Digitized personal monitor data can support the automation of some exposure control decisions or allow such decisions to be made by people in near real-time. The emerging Internet of Things (IoT) offers opportunities to integrate digital exposure data into decision-making to increase both efficiency and safety. The perceived and real uncertainty associated with real-time exposure assessments may be lessened with work to rule out the presence of know interferents and confirm the presence of target analytes.

Evolution and Applications of Recent Sensing Technology for Occupational Risk Assessment: A Rapid Review of the Literature

Over the last decade, technological advancements have been made available and applied in a wide range of applications in several work fields, ranging from personal to industrial enforcements. One of the emerging issues concerns occupational safety and health in the Fourth Industrial Revolution and, in more detail, it deals with how industrial hygienists could improve the risk-assessment process. A possible way to achieve these aims is the adoption of new exposure-monitoring tools. In this study, a systematic review of the up-to-date scientific literature has been performed to identify and discuss the most-used sensors that could be useful for occupational risk assessment, with the intent of highlighting their pros and cons. A total of 40 papers have been included in this manuscript. The results show that sensors able to investigate airborne pollutants (i.e., gaseous pollutants and particulate matter), environmental conditions, physical agents, and workers' postures could be usefully adopted in the risk-assessment process, since they could report significant data without significantly interfering with the job activities of the investigated subjects. To date, there are only few "next-generation" monitors and sensors (NGMSs) that could be effectively used on the workplace to preserve human health. Due to this fact, the development and the validation of new NGMSs will be crucial in the upcoming years, to adopt these technologies in occupational-risk assessment.

Risk management in occupational safety: A systematic mapping

BACKGROUND

Occupational safety risk management is a systemic process capable of promoting technical engineering solutions, considering a wide range of predictable, unexpected and subjective factors related to accident occurrences. In Brazil, the behavior of managers in relation to risk management tends to be reactive, and facilitates access to information for crucial practical and academic purposes when it comes to changing the attitude of managers, so that their actions become increasingly more proactive.

OBJECTIVE

To identify, classify, analyze, and discuss the existing literature related to the topic, produced from 2008 to 2020, besides contributing to a broader understanding of risk management in occupational safety.

METHODS

We did a systematic literature mapping. The research process was documented starting by the planning stage. Afterwards, the focus was on research conduction and information synthesis.

RESULTS

Knowledge systematization and stratification about OHS risk management through various perspectives to identify, analyze and manage risks in the workplace. Were identified 37 tools for identifying and analyzing risks, management-related practices and future research trends.

CONCLUSIONS

The set of tools and management practices identified can be used as a support for decision making in the selection process of tools and practices to reduce risks and improve occupational safety. Also, the results can help target future research.