Most of the occupational exposure limits (OELs) are based on local irritants. However, exposure to much lower concentrations of irritant substances can also lead to health complaints from workers. Exposure to irritants is often accompanied by strong unpleasant odors, and strong odors might have distracting effects and hence pose a safety risk. The findings obtained in human exposure studies with chemically sensitive, stressed, or anxious persons suggest that their ability to direct attention away from the odorous exposure and to focus on a cognitive task is reduced. In addition, after repeated odor exposure, these persons show signs of sensitization, i.e., difficulties in ignoring or getting used to the exposure. The question arises as to whether certain health conditions are accompanied by a change in sensitivity to odors and irritants, so that these persons are potentially more distracted by odors and irritants and therefore more challenged in working memory tasks than nonsusceptible persons. In our study, susceptible persons with sensory airway hyperreactivity (“capsaicin-sensitive”) respond more strongly to mechanical skin stimuli than controls and show altered network connectivity. Capsaicin-sensitive subjects have a lower pain threshold and thus are more sensitive to mechanical skin stimuli. The intrinsic functional connectivity of their saliency network is higher, and the lower the GABAergic tone of the thalamus, the higher their pain sensitivity to mechanical stimuli. It seems that the increased communication between resting-state networks promotes a stronger perception of the sensory input signal. The results can be used to inform about actual risks (i.e., attention diversion and increased risk of accidents) and “pseudo” risks such as odor perception without a negative impact on one’s well-being. This way, uncertainties that still prevail in the health assessment of odorous and sensory irritating chemicals could be reduced.

中文翻译：

---

健康、辣椒素敏感受试者的疼痛感知、大脑连通性和神经化学

大多数职业接触限值 (OEL) 都是基于当地的刺激物。然而，暴露于低得多的刺激性物质也会导致工人的健康问题。接触刺激物往往伴随着强烈的难闻气味，而强烈的气味可能会分散注意力，从而构成安全风险。在对化学敏感、压力大或焦虑的人进行的人体暴露研究中获得的结果表明，他们将注意力从有气味的暴露中转移出来并专注于认知任务的能力降低了。此外，在反复接触气味后，这些人表现出过敏迹象，即难以忽视或习惯接触。问题是，某些健康状况是否伴随着对气味和刺激物的敏感性发生变化，因此，这些人可能更容易被气味和刺激物分心，因此在工作记忆任务中比不敏感的人更具挑战性。在我们的研究中，具有感觉气道高反应性（“辣椒素敏感”）的易感人群对机械皮肤刺激的反应比对照组更强烈，并显示出改变的网络连接。辣椒素敏感的受试者具有较低的痛阈，因此对机械皮肤刺激更敏感。它们的显着性网络的内在功能连接性更高，丘脑的 GABA 能基调越低，它们对机械刺激的疼痛敏感性越高。似乎静息状态网络之间增加的通信促进了对感官输入信号的更强感知。结果可用于告知实际风险（即，注意力转移和事故风险增加）和“伪”风险，例如气味感知，但不会对一个人的健康产生负面影响。通过这种方式，可以减少在气味和感官刺激性化学品的健康评估中仍然普遍存在的不确定性。