Respiratory disease in workers handling cross-linked water-soluble acrylic acid polymer.

Eight workers involved in packing cross-linked water-soluble acrylic acid polymer, an organic substance, developed pulmonary fibrosis, and the upper lobe was the most affected. The dust concentration in the polymer packing workstation was measured. Chest computed tomography (CT) was obtained for 82 individuals, including the 8 workers mentioned above.

o-Toluidine metabolism and effects in the urinary bladder of humanized-liver mice.

Occupational exposure to aromatic amines is one of the most important risk factors for urinary bladder cancer. When considering the carcinogenesis of aromatic amines, metabolism of aromatic amines in the liver is an important factor. In the present study, we administered ortho-toluidine (OTD) in the diet to mice for 4 weeks.

[Investigating erythrocyte hemolysis assay use for proinflammatory potential prediction of silica particles].

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.

2-mercaptobenzothiazole generates γ-H2AX via CYP2E1-dependent production of reactive oxygen species in urothelial cells.

Ortho (o)-toluidine is a widely known carcinogenic substance associated with cancers of the human bladder. A study on British chemical factory workers exposed to 2-mercaptobenzothiazole, phenyl-β-naphthylamine, aniline, and o-toluidine demonstrated the crucial roles of o-toluidine, 2-mercaptobenzothiazole, and phenyl-β-naphthylamine in the development of bladder cancer. As genotoxic events are crucial steps in the initiation of cancer, in the present study, we aimed to examine the genotoxic potential of the four chemicals using phosphorylated histone H2AX (γ-H2AX), which is a sensitive and reliable marker of DNA damage, in cultured human urothelial cells.

Risk of bladder cancer in male Japanese workers exposed to ortho-toluidine and other aromatic amines.

Purpose: Nine bladder cancer (BCa) cases were reported among aromatic amine-exposed male workers at a factory manufacturing organic dye/pigment intermediates in Japan. We aimed to evaluate the characteristics of aromatic amine-exposed workers by cross-sectional observation, and the risk of BCa by assessing the standardized incidence ratio (SIR).

Methods: In the cross-sectional study, our subjects were: 9 BCa patients, 36 aromatic amine-exposed non-patients, and 79 non-exposed workers from 3 factories.

[Examining the association between work-life factors and health disorders/excessive fatigue among Japanese truck drivers].

Objectives: Karoshi problems (overwork-related deaths and disorders caused by cerebrovascular and cardiovascular diseases) still occur in Japan. Truck drivers, who are in one of the riskiest occupations, are reported to show an increased prevalence of hypertension, obesity, hyperlipidemia, and diabetes, which are characteristic of Karoshi. Their health problems also include excessive fatigue.

Shorter sleep duration is associated with potential risks for overwork-related death among Japanese truck drivers: use of the Karoshi prodromes from worker's compensation cases.

Purpose: We aimed to cross-sectionally investigate how work and sleep conditions could be associated with excessive fatigue symptoms as an early sign of Karoshi (overwork-related cerebrovascular and cardiovascular diseases; CCVDs).

Methods: We distributed a questionnaire regarding work, sleep, and excessive fatigue symptoms to 5410 truck drivers, as the riskiest occupation for overwork-related CCVDs, and collected 1992 total samples (response rate: 36.8%).

[Management of occupational health for adverse health effects of beryllium and its compounds in workplaces - Recent trends and issues in Japan].

Objectives: Beryllium is primarily used in its metallic form, in alloys, or in beryllium oxide ceramics. Its physical and mechanical properties make it useful for many applications across a range of industries. Because beryllium is recognized as a sensitizing and carcinogenic agent, the management of occupational health for workers who may be occupationally exposed to beryllium has long been an important issue in the world.

Comparative γ-H2AX analysis for assessment of the genotoxicity of six aromatic amines implicated in bladder cancer in human urothelial cell line.

Recently, it was reported that ten cases of bladder cancer occurred among employees, who handled several kinds of aromatic amines, at a Japanese chemical plant. The common aromatic amines were identified as ortho-toluidine, para-toluidine, aniline, ortho-chloroaniline, ortho-anisidine, and 2,4-dimethylaniline. All of these aromatic amines, except ortho-chloroaniline, have been found to be carcinogenic in animals and/or humans.

Promotion effects of acetoaceto-o-toluidide on N-butyl-N-(4-hydroxybutyl)nitrosamine-induced bladder carcinogenesis in rats.

Recent epidemiological studies have indicated that occupational exposure to the aromatic amine acetoaceto-o-toluidide (AAOT) was associated with a marked increase in urinary bladder cancers in Japan. However, little is known about the carcinogenicity of AAOT. To evaluate the urinary bladder carcinogenicity of AAOT, male and female F344 rats were treated with N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) for 4 weeks followed by dietary administration of 0, 0.

Priority approaches of occupational safety and health activities for preventing low back pain among caregivers.

Objectives: The incidence of occupational low back pain (LBP) is high among caregivers. The use of care equipment and training about care methods could prevent LBP among caregivers. However, in care facilities in Japan, these measures are not adequately employed.

2,4-Dimethylaniline generates phosphorylated histone H2AX in human urothelial and hepatic cells through reactive oxygen species produced by cytochrome P450 2E1.

The Japanese Ministry of Health, Labour, and Welfare recently reported an outbreak of bladder cancer among workers who handled aromatic amines in Japan. 2,4-dimethylaniline (2,4-DMA) is one of the chemicals that workers are considered to have the most opportunities to be exposed. Genotoxic events are known to be crucial steps in the initiation of cancer.

Effectiveness of re-education based on appropriate care methods using welfare equipment on the prevention of low back pain among care workers: a 1.5 year follow-up study.

Many care workers at elderly care facilities in Japan suffer occupational low back pain (LBP) despite the utilization of welfare equipment. When introducing welfare equipment such as hoists and sliding boards, education on appropriate care methods using welfare equipment is usually conducted, but the effect of education diminishes with time. This intervention study aimed to examine the effect of re-education on appropriate care methods using welfare equipment on the prevention of care workers' LBP at an elderly care facility.

An epidemic of bladder cancer: ten cases of bladder cancer in male Japanese workers exposed to ortho-toluidine.

Background: ortho-Toluidine (OT) was listed as a Group 1 carcinogen by the International Agency for Research on Cancer in 2012 based on epidemiological observations of workers co-exposed to OT and aromatic amines. From 2014 to 2017, several cases of bladder cancer (BCa) secondary to occupational exposure, primarily to OT, were detected in Japan.

Objective: To describe 10 cases of BCa in male Japanese workers exposed primarily to OT at two plants that produce organic dye and pigment intermediates.

Prenatal mercury exposure and birth weight.

Adverse effects of prenatal mercury exposure on pregnancy outcomes remain a public health concern. We assessed the relationship between prenatal mercury exposure and newborn anthropometric characteristics in 334 mother-child pairs from the early stages of pregnancy to delivery in Tokyo, Japan, between December 2010 and October 2012. We found a negative correlation between blood mercury levels during the first and second trimesters of gestation and birth weight (r = -0.

[Low back pain among workers in care facilities for the elderly after introducing welfare equipment].

Objective: The purpose of this study was to clarify the causes of low back pain among workers in care facilities for the elderly after the introduction of welfare equipment.

Methods: We conducted anonymous questionnaire surveys among administrators and care workers in eight elderly care facilities. The questionnaires were designed to investigate the status of both the care workers and facility.

Association between occupational exposure and control measures for antineoplastic drugs in a pharmacy of a hospital.

Objectives: To investigate the association between occupational contamination and exposure levels to antineoplastic drugs and the application of control measures in a hospital work environment.

Methods: Wipe samples of equipments were collected at a hospital in Osaka Prefecture, Japan, from 2007 to 2011. These samples were subjected to measurements of cyclophosphamide (CP), gemcitabine (GEM), platinum-containing drugs (Pt), and fluorouracil (5FU).

Evaluation of exposure risk in the weaving process of MWCNT-coated yarn with real-time particle concentration measurements and characterization of dust particles.

Various applications of multiwalled carbon nanotubes (MWCNT) have been developed. One of these applications is an efficient sheet heating element that is woven from MWCNT-coated yarn. In this research, we assessed the exposure to MWCNT and/or the probability of particle release from broken MWCNT-coated yarn during the weaving process.

Circulatory and central nervous system responses to different types of mental stress.

The purpose of the present study was to compare the physiological responses to different types of mental stress encountered in the workplace. Circulatory and central nervous system responses were examined in 8 healthy males by exposing them to 20-min of white noise (80 dB(A)) and 20-min of computer-based mental arithmetic tasks as models of vascular and cardiac stress, respectively. The results indicated that both cardiac and vascular stresses increased blood pressure and showed a cumulative effect as exposure period was extended.

Translocation of intratracheally instilled multiwall carbon nanotubes to lung-associated lymph nodes in rats.

In order to assess the extrapulmonary effects of multiwall carbon nanotubes (MWCNT), deposition of MWCNT and histopathologic changes in lung-associated lymph nodes (LALN) were examined in MWCNT-administered rats. At the age of 13 wk, male F344 rats were intratracheally instilled with MWCNT at a dose of 0 (vehicle), 40 or 160 μg/rat. The rats were sacrificed on Day 1, 7, 28 or 91 after instillation and light microscopic examinations were performed on LALN tissues.

Association between occupational exposure levels of antineoplastic drugs and work environment in five hospitals in Japan.

Purpose: The aim of the present study was to evaluate the measurement of contamination by antineoplastic drugs for safer handling of such drugs by medical workers. We investigated the relationship between the contamination level of antineoplastic drugs and the conditions of their handling.

Methods: Air samples and wipe samples were collected from equipment in the preparation rooms of five hospitals (hospitals A-E).

Pulmonary toxicity of intratracheally instilled multiwall carbon nanotubes in male Fischer 344 rats.

In order to assess pulmonary toxicity of multiwall carbon nanotubes (MWCNT), male F344 rats were intratracheally instilled with MWCNT suspension at a dose of 40 or 160 μg/head or α-quartz particles as a positive control at a dose of 160 μg/head and sacrificed for lung histopathology and bronchoalveolar lavage (BAL) fluid analyses on Day 1, 7, 28 or 91 after instillation. Well-dispersed MWCNT brought about dose- or time-dependent changes in lung weight, total proteins, albumin, lactate dehydrogenase and alkaline phosphatase in the BAL fluid, and pulmonary lesions including inflammation, Type II cell hyperplasia, microgranulomas and fibrosis. Phagocytosed and free forms of MWCNT were found in both bronchiolar and alveolar spaces.

[Airborne particles in a multi-wall carbon nanotube production plant: observation of particle emission and personal exposure 1: Measurement in the packing process].

Objectives: In order to assess the exposure risks of multiwall carbon nanotubes (MWCNT) for packing workers, we carried out real-time monitoring in the two types of packing facilities of MWCNT, and exposure measurements for the packing workers.

Methods: In the real-time monitoring, a scanning mobility particle sizer (SMPS) and an optical particle counter (OPC) were used to measure nanoscale particles and sub-micron/micron scale particles, respectively. A personal sampler with PM 4.