Abstract

The Internet of Things (IoT) explores new perspectives and possible improvements in risk assessment practices and shows potential to measure long-term and real-time occupational exposure. This may be of value when monitoring gases with short-term maximum levels and for time-weighted average (TWA) concentrations used in standard measuring practices. A functional embedded system was designed using low-cost carbon monoxide (CO) electrochemical sensors and long-range-wide-area-network radio communication technology (LoRaWAN) was used to enable internet connectivity. This system was utilized to monitor gas levels continuously in the working atmosphere of an incineration plant over a 2-month period.

The results show that stable and long-term continuous data transfer was enabled by LoRaWAN, which proved useful for detecting rapid changes in gas levels. However, it was observed that raw data from the low-cost sensors did not meet the NIOSH accuracy criteria of $\pm$25% of the estimated true concentration based on field data from a co-located gas detector that met the NIOSH accuracy criteria. The new IoT technologies and CO sensor networks shows potential for remote monitoring of exposure in order to: (1) detect rapid changes in CO and other possible hazardous airborne gases; and (2) show the dynamic range of real-time data that may be hazardous for workers in the sampled areas. While the IoT low-cost sensors appear to be useful as a sentinel for monitoring hazardous atmospheres containing CO, the more useful finding may be showing real-time changes and the dynamic range of exposures, thus shedding light on the transient and toxic nature of airborne hazards. More importantly, the low-cost CO sensors are not a clear substitute for the more costly real-time gas detectors that perform within the NIOSH accuracy criteria.

摘要

物联网（IoT）探索了风险评估实践的新观点和可能的改进，并显示了测量长期和实时职业暴露的潜力。当监测短期最大浓度的气体以及标准测量实践中使用的时间加权平均（TWA）浓度时，这可能很有价值。使用低成本一氧化碳（CO）电化学传感器设计了功能嵌入式系统，并使用了远程广域网无线电通信技术（LoRaWAN）来实现Internet连接。该系统用于在两个月的时间内连续监测焚化厂工作气氛中的气体水平。

结果表明，LoRaWAN能够实现稳定且长期的连续数据传输，这对于检测气体浓度的快速变化非常有用。但是，据观察，来自低成本传感器的原始数据不符合NIOSH精度标准，即$\pm$根据符合NIOSH精度标准的同位气体探测器的现场数据，估算的真实浓度的25％。新的物联网技术和一氧化碳传感器网络显示了对暴露进行远程监控的潜力，以便：（1）检测一氧化碳和其他可能的有害空气中气体的快速变化；（2）显示了实时数据的动态范围，该范围可能对采样区域的工人有害。尽管物联网低成本传感器似乎可以用作监测含有CO的危险环境的哨兵，但更有用的发现可能是显示实时变化和暴露的动态范围，从而揭示机载气体的瞬态和有毒性质危害。更重要的是，