Objectives: The studies on occupational peripheral nerve disorders (OPD) in the workplace and future issues of OPD were overviewed based on the author’s experiences. Methods: The author shows four case studies because of four chemicals; cross-sectional studies using nerve conduction velocity (NCV) on the effect on the peripheral nerve among workers exposed to carbon disulphide (CS₂) in rayon manufacturing factories and studies on OPD among patients with vibration syndrome (VS) and non-specific cervicobrachial disorders (CBD). Results: Four cases of OPD due to chronic poisoning because of inorganic lead, thallium, n-hexane, and methyl bromide, respectively, were presented with clinical signs and symptoms of OPD and the cause-and-effect relationships were described. Cross-sectional epidemiological studies clarified that workers exposed to approximately 5 ppm of CS₂ showed NCV reduction in the lower extremities and those exposed to > 5 ppm showed NCV reduction in the upper extremities. Multifocal damages due to VS was presented through high rate of patients with sensory nerve conduction velocity (SCV) reduction in multiple nerves. SCV reduction of the radial nerve in the index finger among patients with CBD was presented. Conclusions: The various OPD phases were shown by case, patient, and epidemiological study. However, the recent decrease of work-related illness due to chemicals may result to OPD reduction. The issue of OPD including other factors and differential diagnosis, will remain eventually owing to introducing chemicals of which toxicity are unclear.

Objectives: Crystalline silica, which is a causative agent of silicosis (an occupational disease), is manufactured in a variety of products (particles) with different particle characteristics, such as size and surface properties. In Japan, the products are currently uniformly controlled as crystalline silica, which is a substance subject to labeling and notification requirements. However, since the toxicity of silica particles reportedly varies depending on its characteristics, businesses are encouraged to conduct appropriate risk assessments for each product to prevent silicosis. Recently, silica particles have been reported to induce lysosomal membrane damage, leading to the activation of proinflammatory factors. An indirect method to evaluate lysosomal membrane damage known as the erythrocyte hemolysis assay, in which the erythrocyte membrane is assumed to be the lysosomal membrane, was performed. This study aimed to examine the possibility of constructing a screening system for proinflammatory potential prediction of silica particles based on their erythrocyte hemolytic activity. Methods: Hemolysis assays were performed on the silica particles with different sizes, crystallinity, and surface functional groups using the erythrocytes from a healthy volunteer. Additionally, the hemolytic activity of other element particles was compared with that of the silica particles, and 27 types of commercially available crystalline silica particle products underwent screening trials. Results: The hemolytic activity of silica particles was higher in crystalline than that in amorphous and increased with the decreasing size. The hemolytic reaction was particular to silica particles and rarely occurred in particles of other elements. Moreover, the hemolytic activity was significantly suppressed if the silica particles surface was modified with metal ions (Fe³⁺, Al³⁺). The hemolytic activities of the crystalline silica products used industrially significantly differed. Conclusions: This study revealed that particle properties, such as size, crystallinity, and surface functional groups, affect the hemolytic activity of silica particles. Particularly, the surface functional groups (silanol groups) that are unique to silica particles were considered to be strongly involved in hemolytic activities. Since grading the commercially available crystalline silica particle products based on the hemolytic rate was possible, hemolytic activity was suggested to be an evaluation index for predicting the proinflammatory potential of silica particles.

Objectives: Medically, anticancer drugs contamination leading to human exposure has become an issue. The urine of patients receiving chemotherapy contains anticancer drugs. If urine containing anticancer drugs is excreted, the anticancer drugs are scattered around the toilet bowl, then adhere to slipper soles and spread. Therefore, we developed an absorbent sheet containing activated carbon that absorbs anticancer drugs and prevents anticancer drug contamination spread. In this article, we report the data on the sheet performance evaluation. Methods: In artificial urine solutions, 100 μL (20 drops) of cyclophosphamide (CPA; 2,000 μg/mL), methotrexate (MTX; 6,000 μg/mL), and paclitaxel (PTX; 200 μg/mL) were dropped onto the stainless plate of two commercially available medical sheets (Pitapa Sheet^Ⓡ; control product 1 and Absocare sheet^Ⓡ; control product 2) and a newly developed sheet (HD Safe Sheet-Neo, test product). Polyvinyl chloride (PVC) slippers were placed on the sheets for 30 s, and anticancer drugs that adhered to the slippers were quantified. We compared the drug quantities that were transferred to the slippers from different sheets. Results: An average of 31.5%, 38.7%, and 50.5% of each of the dropped anticancer agents (CPA, MTX, and PTX, respectively) adhered to the slipper sole. Compared to that of the control product 2, the average adhesion of CPA and MTX was significantly reduced in the test product containing activated charcoal (224 vs 2 μg, p < .050 and 2,235 vs 19 μg, p < .050). Contrastingly, there was no significant difference in the PTX mean adherence (35 vs 13 μg). Conclusion: Activated carbon adsorbs anticancer drugs in urine. The test product containing activated charcoal reduced the amount of scattered anticancer drugs that adhered to the slippers. The results suggest that the activated carbon sheet may prevent anticancer drugs contamination spread in urine.

Objectives: Labor and social security attorneys (LSSAs) are involved in various positions in harmonizing work with disease treatment; however, their qualification requirements do not include knowledge about the same. Expectations of their involvement in harmonizing work with disease treatment are insufficient. This study aimed to identify the competencies expected of the labor and social security LSSAs in harmonizing work with disease treatment. Methods: In step 1, semi-structured interviews were conducted with LSSAs in this field. In step 2, a draft competency list was created based on the interview results. In step 3, the Delphi method was used to conduct a questionnaire survey among LSSAs who had over 10 consultation cases on harmonizing work with disease treatment, and they were asked about the level of importance (how important they thought it was to promote harmonizing work with disease treatment) and level of achievement (how much they had achieved). We also asked them about the competencies they considered necessary and added them as additional items in the draft. In step 4, the results of the previous step were presented to the participants who had given valid answers in step 3, and they were asked whether they would adopt the items as competencies. Items with an agreement rate of 80% or higher were considered competency items. Additionally, we asked them about the level of importance and level of achievement of the additional items created in step 3. Results: In step 1, 24 LSSAs participated, and in step 2, a draft competency list of six major items, 18 medium items, and 71 minor items was created. In step 3, 49 LSSAs participated and 41 cooperated (response rate: 83.6%). Five items were selected for the draft competency list to be newly added. In step 4, 30 LSSAs cooperated (response rate: 73.1%). None of the items had an agreement rate of less than 80%, and over 40% of the items had an agreement rate of 100%. As a result, six major items, 18 medium items, and 76 minor items were selected for the competency list. Conclusions: This study identified the competencies expected of labor and social security LSSAs in harmonizing work with disease treatment. The results of this study can be used as a reference for developing a systematic training curriculum for LSSAs in this field in the future.