Evaluation of hand-arm vibration syndrome owing to nerve conduction study and cumulative exposure index -A 2.5-year cohort study.

OBJECTIVE: This study aims to clarify the relationship between peripheral neuropathy in hand-arm vibration syndrome and cumulative exposure index. METHODS: 68 participants without symptoms were surveyed. The participants were divided into three groups based on past and current vibration exposure (VE). RESULTS: Comparison among groups according to past VE showed that the median and ulnar sensory nerve conduction velocities and median sensory nerve action potential (SNAP) amplitude were significantly lower in past high and low exposure groups than in the past non-exposure group. Comparison among groups according to current VE showed that the median and ulnar SNAP amplitudes were significantly lower in the current high exposure group than in the current low or non-exposure group. CONCLUSIONS: Vibration tool handlers have potential peripheral nerve lesions at a certain stage without subjective symptoms of the finger.

[Evaluation of self-administered questionnaire items used in regular health check-ups at the workplace by occupational health professionals].

OBJECTIVE: Currently, there is no standardized questionnaire for regular workplace health check-ups in Japan. We considered that there are several issues associated with this, including the possibility that the questionnaire items are not useful for occupational health staff. Therefore, our study aimed to examine the questionnaire items required in regular health check-ups from the occupational health practice perspective and prepare a draft of a standardized medical questionnaire. The ultimate goal is to promote integrated management and utilization of the health-related information obtained from the questionnaire in the future. METHODS: This non-interventional study, conducted from February 2018 to November 2020, examined the questionnaire items for the regular health check-up using the Delphi method. Twenty-two occupational health professionals, including occupational physicians and nurses with qualifications in occupational health, participated in the study. The self-administered questionnaires used by contracted industrial health associations across Japan were obtained, and items from all questionnaires were extracted. A survey questionnaire was then developed, consisting of eight primary headings: "personal attributes," "work-related information and work history," "life history and subjective symptoms," "current and past medical history," "family history," and "pregnancy status," with a total of 589 items. Participants were asked to rate the degree of necessity for each item, excluding the items in "personal attributes" and "pregnancy status." The items with low ratings were excluded, and the remaining items were redesigned and distributed to the participants with the tabulated results. This process was repeated three times to allow the participants to rate the necessity of the items consistently. The questionnaire items with a consensus ratio exceeding 70% on the third try were adopted. The final adopted questionnaire items were again reviewed by the participants and agreed upon by all. RESULTS: A total of 85 items were adopted under five primary headings, including 12 items for "work-related information and work history," 11 for "life history," 22 for "subjective symptoms," 37 for "current medical history," and three for "past medical history." CONCLUSION: The items for the regular health check-up were finally adopted under the primary headings of "work-related information and work history," "subjective symptoms," and "current medical history." We assumed that these items provide an overview of health information that can be utilized in occupational health practice. Based on our findings, there is a need to develop a standardized questionnaire for regular health check-ups and to consider the management and utilization of workers' health information.

Application of tight-fitting half-facepiece breath-response powered air-purifying respirator for internal body cooling in occupational environment.

In dust-generating scenarios in occupational environments, it is important to take measures to prevent not only pneumoconiosis, but also heatstroke. The aim of this study was to verify whether using a tight-fitting half-facepiece breath-response powered air-purifying respirator (PAPR) in combination with a self-produced cooling device could abate the deep body temperature while performing activities. We conducted a crossover study involving 10 subjects. The subjects were subjected to three conditions: wearing a PAPR equipped with a cooling device, PAPR, or a replaceable particulate respirator. During the experiment, the rectal temperature of the subjects was measured, along with the temperature near the PAPR inlet in container with the cooling device when the PAPR equipped with the cooling device was worn. The subjects rested in a cold chamber set at a dry-bulb temperature of 28°C and relative humidity of 45% for 20 min. Then, they moved to a hot chamber set to a dry-bulb temperature of 36°C (with the same relative humidity) in 5 min and exercised on a cycle ergometer for 30 min. After that, the subjects moved to the cold chamber for 5 min and rested for 20 min. Notably, the air inhaled by the subjects wearing PAPR equipped with the cooling device was approximately 10°C cooler than the ambient air. Furthermore, 35 min after the initiation of the experiment (after the middle of the exercise period), the rectal temperature of the participants wearing the PAPR equipped with the cooling device was lower than of those wearing PAPR or replaceable particulate respirators (p <0.05). Thus, we could deduce that the self-produced cooling device was useful in abating deep body temperature. PAPR is useful for its potential applications in hot occupational environments and can save lives in working environments where heat stress can result in major medical complications.

Visualization of Dust Generation in Outdoor Workplaces Using A Wearable Particle Monitor and Global Navigation Satellite System.

We manufactured a wearable particle monitor (WPM), which is a simple and low-cost dust monitor. We aimed to evaluate the usefulness of the device by using it and location information of a Global Navigation Satellite System (GNSS) to measure dust generation in outdoor workplaces. We used nine WPMs and a particle counter KC-52 to measure in parallel the dust concentration diffusing standard particles in a dust exposure apparatus to evaluate the measurability of the WPM, and visualized dust generation in outdoor workplaces to evaluate its usability. We obtained location information using a GNSS in parallel with measuring with the WPM. The measured values of the WPM followed the measured values of the KC-52, with a strong correlation of the values between the KC-52 and each WPM. The discrepancy among devices tended to increase, however, because the measured values of the WPMs increased. For outdoor measurements, we could create a heat map of the relative values of dust generation by combining two data of the WPM and the GNSS. The methods of using the WPM could overview the conditions needed to produce dust emissions in dust-generating workplaces.

Measurement of the Workplace Protection Factor of Replaceable Particulate and Powered Air-purifying Respirators in Japanese Dust-generating Occupations.

Although measuring the workplace protection factor (WPF) is important to verify the performance of particulate respirators in a real work environment, there are no reports of such measurements in Japan. The aim of this study was to measure the WPF of a replaceable particulate respirator (RPR) and a powered air-purifying respirator (PAPR). Eight participants were subjected to three conditions: wearing a RPR correctly (C-RPR), wearing a RPR as usual (but incorrectly) (U-RPR), and wearing a PAPR in the same way as U-RPR (PAPR). Subjects performed dust-generating tasks for 15 min, during which the WPF was measured. The WPF was calculated by dividing the concentration of particles outside the particulate respirator (Co) by that inside the particulate respirator (Ci). A fit testing instrument was used to measure the number of particles. Ci was measured by inserting the test guide into the face piece, and Co was measured by fixing the test guide near the breathing area of the subjects. The WPF geometric mean values (standard deviations) for C-RPR, U-RPR, and PAPR were 17.7 (2.59), 27.0 (3.86), and 117.3 (5.25), respectively. It is important to generate knowledge about the performance of particulate respirators to prevent occupational respiratory diseases.

Combining Indoor Positioning Using Wi-Fi Round Trip Time with Dust Measurement in the Field of Occupational Health.

Monitoring of personal exposure to hazardous substances has garnered increasing attention over the past few years. However, no straightforward and exact indoor positioning technique has been available until the recent discovery of Wi-Fi round trip time (Wi-Fi RTT). In this study, we investigated the possibility of using a combination of Wi-Fi RTT for indoor positioning and a wearable particle monitor (WPM) to observe dust concentration during walking in a simulated factory. Ultrasonic humidifiers were used to spray sodium chloride solution inside the factory. The measurements were recorded three times on different routes (Experiments A, B, and C). The error percentages, i.e., measurements that were outside the expected measurement area, were 7% (49 s/700 s) in Experiment A, 2.3% (15 s/660 s) in Experiment B, and 7.8% (50 s/645 s) in Experiment C. The dust measurements were also recorded without any obstruction. A heat map was created based on the results from both measured values. Wi-Fi RTT proved useful for computing the indoor position with high accuracy, suggesting the applicability of the proposed methodology for occupational health monitoring.

First report of human parechovirus type 3 infection in a pregnant woman.

Human parechovirus type 3 (HPeV3) can cause serious conditions in neonates, such as sepsis and encephalitis, but data for adults are lacking. The case of a pregnant woman with HPeV3 infection is reported herein. A 28-year-old woman at 36 weeks of pregnancy was admitted because of myalgia and muscle weakness. Her grip strength was 6.0kg for her right hand and 2.5kg for her left hand. The patient's symptoms, probably due to fasciitis and not myositis, improved gradually with conservative treatment, however labor pains with genital bleeding developed unexpectedly 3 days after admission. An obstetric consultation was obtained and a cesarean section was performed, with no complications. A real-time PCR assay for the detection of viral genomic ribonucleic acid against HPeV showed positive results for pharyngeal swabs, feces, and blood, and negative results for the placenta, umbilical cord, umbilical cord blood, amniotic fluid, and breast milk. The HPeV3 was genotyped by sequencing of the VP1 region. The woman made a full recovery and was discharged with her infant in a stable condition.