Measuring the effects of respiratory protective equipment and other protectors in preventing the scattering of vocalization droplets.

This study was conducted to quantitatively examine the effects of respiratory protective equipment (respirators) and various other types of protectors in preventing the scattering of vocalization droplets. Each of 12 adult male volunteers was asked to vocalize intermittently for 1 min at a target intensity of approximately 100 dBA in an experimental room adjusted to a humidity of approximately 60-70%. The subjects vocalized while wearing respirators, other types of protectors, or no protectors at all.

Literature review to integrate information to assist workers to select masks even at workplaces without occupational health personnel.

Background: With the COVID-19 pandemic, the idea of universal mask wearing to prevent infecting others when one becomes infected has prevailed among people. In general, any workplace is not exempt and workers are required to wear a mask while working at the sites.

Objectives: This study aims to integrate information to assist workers to select effective protectors for the prevention of droplet infection even at workplaces without occupational health personnel.

Efficacy of ice slurry and carbohydrate-electrolyte solutions for firefighters.

Objectives: To examine the thermoregulatory and fluid-electrolyte responses of firefighters ingesting ice slurry and carbohydrate-electrolyte solutions before and after firefighting operations.

Methods: Twelve volunteer firefighters put on fireproof clothing and ingested 5 g/kg of beverage in an anteroom at 25°C and 50% relative humidity (RH; pre-ingestion), and then performed 30 minutes of exercise on a cycle ergometer (at 125 W for 10 minutes and then 75 W for 20 minutes) in a room at 35℃ and 50% RH. The participants then returned to the anteroom, removed their fireproof clothing, ingested 20 g/kg of beverage (post-ingestion), and rested for 90 minutes.

Development of a method for estimating oesophageal temperature by multi-locational temperature measurement inside the external auditory canal.

We aimed to develop a practical method to estimate oesophageal temperature by measuring multi-locational auditory canal temperatures. This method can be applied to prevent heatstroke by simultaneously and continuously monitoring the core temperatures of people working under hot environments. We asked 11 healthy male volunteers to exercise, generating 80 W for 45 min in a climatic chamber set at 24, 32 and 40 °C, at 50% relative humidity.

Urinary 1-hydroxypyrene levels among office workers living in industrial areas.

We examined exposure to polycyclic aromatic hydrocarbons (PAHs) among non-smoking office workers in 2 countries living in the vicinity of a coke-oven factory by measuring their levels of urinary 1-OHP, a known metabolite of PAHs. Subjects included 10 non-smoking office workers in Kitakyushu city (Japan) and 20 workers in Thai Nguyen city (Vietnam). Measurement was optimized by using the high-performance liquid chromatography (HPLC) method developed by Jongeneelen et al.

Urinary 1-hydroxypyrene and 8-hydroxydeoxyguanosine levels among coke-oven workers for 2 consecutive days.

Objectives: This study evaluated the levels of exposure to polycyclic aromatic hydrocarbons (PAHs) and their relationship with oxidative DNA damage among Vietnamese coke-oven workers.

Methods: We collected urine from 36 coke-oven workers (exposed group) at the beginning and end of the shift on 2 consecutive days. We also collected urine from 78 medical staff (control group).

Urine temperature as an index for the core temperature of industrial workers in hot or cold environments.

Workers working in hot or cold environments are at risk for heat stroke and hypothermia. In Japan, 1718 people including 47 workers died of heat stroke in 2010 (Ministry of Health Labour and Welfare, Japan 2011). While the American Conference of Governmental Industrial Hygienists (ACGIH) recommendation lists the abnormal core temperature of workers as a criterion for halting work, no method has been established for reliably measuring core temperatures at workplaces.

[Assessment of telephone operators' exposure to sound through headphones].

We estimated the level of noise that telephone operators were exposed to through headphones by a two-step method using an artificial ear technique and a manikin technique. In the artificial ear technique, the sound pressure level (Leq) of the total work hours was 81.5 dB, whereas the Leq of the total duration of phone calls was 89.

Assessments by HR and %HRR of occupational work exertion for alternating periods of rest and manual labor.

Objectives: Metabolic equivalents (METs) and relative metabolic rate (RMR) as calculated by oxygen uptake (VO(2)) are often used to assess physical exertion. In practice, accurate measurements of VO(2) are difficult; heart rate (HR) values represent an alternate index of physical exertion. We investigated whether one can assess physical exertion based on HR in the workplace, even if the physical task in question involves alternating periods of strenuous anaerobic activity and rest.

Expression of heme oxygenase-1 in the lungs of rats exposed to potassium octatitanate whiskers.

Objectives: Oxidative stress is thought to be the pathogenesis of pulmonary fibrosis induced by asbestos, and heme oxygenase-1 (HO-1) protects lung tissue against oxidative stress. We hypothesized that HO-1 is also associated with oxidative lung injury caused by exposure to potassium octatitanate whiskers (PT1), which is one of the asbestos substitutes.

Methods: Male Wistar rats were administered 1 mg or 2 mg PT1 suspended in saline by a single intratracheal instillation and were sacrificed after recovery for 3 days, 1 wk, 1 mo, 3 mo or 6 mo.

Effort-reward imbalance and depression among private practice physicians.

Purpose: Current private practice physicians provide medical services in a harsh economic situation. The effort-reward imbalance (ERI) model puts its emphasis on an imbalance between high efforts spent and low rewards received in occupational life. ERI model includes three different reward factors from task to organizational levels.