OBJECTIVESRecently, perfluorooctanoate (PFOA) has been ubiquitously detected in the environment as well as in human serum. Fluorotelomer alcohols (FTOHs), a precursor of PFOA, undergo biodegradation via several metabolic routes which leads to formation of various biodegradation products. The degradation of FTOHs produces an α,β-unsaturated aldehyde that seems possibly to be electrophilic and may react with cellular macromolecules including DNA.

METHODSWe investigated the genotoxicity of three FTOHs (6∶2 FTOH, 8∶2 FTOH and 10∶2 FTOH), PFOA and perfluorooctane sulfonate (PFOS) using theumu test.

RESULTSThe FTOHs, PFOA and PFOS showed no significant increases in β-galactosidase activity at 0-1000 μM in the absence of S9 mix. The results were unchanged by the metabolic activation with S9 mix.

CONCLUSIONThe genotoxicities of FTOHs, PFOA or PFOS are not detectable using the present method, suggesting that they are unlikely mutagens.

Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) comprise a class of per- and poly-fluorinated compounds that have been detected in the environment as well as in humans. The aim of this review is to summarize several monitoring studies in Japan and characterize the toxicokinetics of these compounds. We found that the levels of contamination by these compounds had unique patterns in Japan. The levels of PFOA in serum from inhabitants of the Kansai region were higher than those of other regions. The PFOA levels in air and water samples from the Kansai region were also relatively high. The estimated intakes from these routes partly explain the differences in the serum levels. The toxicokinetics of these compounds have been investigated. Serum samples from male participants had significantly higher geometric means for PFOS and PFOA compared to samples from female participants. This sex-related difference was partly simulated by menstrual blood loss. There are large interspecies differences in the excretion pathways of these compounds. The serum clearances of PFOA via urine were 300-1,000-fold lower in humans than in Wistar rats and Japanese macaques. On the other hand, the biliary excretion of these compounds was comparable in rats and humans, and the long half-lives in humans may be attributable to the low levels of urinary excretion and high biliary reabsorption rates. These findings suggest that qualitative differences in the excretion routes exist between humans and other species. For risk assessment of these compounds, further information regarding sources of exposure and their toxicokinetics is needed.

BACKGROUND: Healthcare workers (HCWs) employed personal protective equipment (PPE) during the COVID-19 pandemic, crucial to protecting themselves from infection. To highlight the efficacy of PPE in preventing environmental infection among HCWs, a systematic review was conducted in line with PRISMA guidance. METHODS: A search of the PubMed and Web of Science databases was conducted from January 2019 to April 2021 using pre-defined search terms. Articles were screened by three researchers. The approved papers were read in full and included in this review if relevance was mutually agreed upon. Data were extracted by study design and types of PPEs. RESULTS: 47 of 108 identified studies met the inclusion criteria, with seven reviews and meta-analyses, seven cohort, nine case-control, fifteen cross-sectional studies, four before and after, four case series, and one modeling studies. Wearing PPE offered COVID-19 protection in HCWs but required adequate training. Wearing surgical masks provided improved protection over cloth masks, while the benefit of powered air-purifying respirators is less clear, as are individual gowns, gloves, and/or face shields. CONCLUSIONS Wearing PPE, especially facial masks, is necessary among HCWs, while training in proper use of PPE is also important to prevent COVID-19 infection.
Humans ; COVID-19/prevention & control* ; Pandemics/prevention & control* ; Cross-Sectional Studies ; Personal Protective Equipment ; Health Personnel

OBJECTIVETeeth can serve as records of environmental exposure to heavy metals during their formation. We applied a new technology - synchrotron radiation microbeams (SRXRF) - for analysis of heavy metals in human permanent teeth in modern and historical samples.

METHODSEach tooth was cut in half. A longitudinal section 200 mum in thickness was subjected to the determination of the heavy metal content by SRXRF or conventional analytical methods (ICP-MS analysis or reduction-aeration atomic absorption spectrometry). The relative concentrations of Pb, Hg, Cu and Zn measured by SRXRF were translated in concentrations (in g of heavy metal/g of enamel) using calibration curves by the two analytical methods.

RESULTSConcentrations in teeth in the modern females (n = 5) were 1.2 +/- 0.5 mug/g (n = 5) for Pb; 1.7 +/- 0.2 ng/g for Hg; 0.9 +/- 1.1 mug/g for Cu; 150 +/- 24.6 mug/g for Zn. The levels of Pb were highest in the teeth samples obtained from the humans of the Edo era (1603-1868 AD: ) (0.5-4.0 mug/g, n = 4). No trend was observed in this study in the Hg content in teeth during 3,000 years. The concentrations of Cu were highest in teeth of two medieval craftsmen (57.0 and 220 mug/g). The levels of Zn were higher in modern subjects (P < 0.05) than those in the Jomon (~1000 BC: ) to Edo periods [113.2 +/- 27.4 (mug/g, n = 11)]. Reconstruction of developmental exposure history to lead in a famous court painter of the Edo period (18th century) revealed high levels of Pb (7.1-22.0 mug/g) in his childhood.

CONCLUSIONSSRXRF is useful a method for reconstructing human exposures in very long trends.

OBJECTIVEExposure to polychlorinated biphenyls (PCBs) is considered to have culminated between 1950 and 1970 in Japan, and exposure through diet, the major exposure route, has decreased significantly over the last 10 years. The primary goal of the present study was to investigate the long-term trends and congener profiles of serum and dietary levels of PCBs using historical samples.

METHODSUsing banked samples collected in 1980, 1995, and 2003 surveys, we determined the daily intakes and serum concentrations of 13 PCB congeners (#74, #99, #118, #138, #146, #153, #156, #163, #164, #170, #180, #182, and #187) in women.

RESULTSThe total daily PCB intake [ng/day, geometric mean (geometric standard deviation)] decreased significantly from 523 (2.5) in 1980 to 63 (3.2) in 2003. The serum total PCB level (ng/g lipid) in women <40 years of age decreased significantly from 185 (1.8) in 1980 to 68 (1.8) in 2003. In contrast, the level in women >50 years of age increased significantly from 125 (1.7) in 1980 to 242 (1.7) in 2003. Specifically, the serum concentrations of hexa (#138, #146, #153, #156, #163, and #164) and hepta (#170, #180, #182, and #187) congeners increased significantly. A comparison of the serum PCB levels of women born from 1940 to 1953 revealed that their serum total PCB level was significantly higher in the 2003 survey [242 (1.7), n = 9] than in the 1995 [128 (2.0), n = 17] surveys. This increase in the total PCB level was attributable to increases in the hepta congener groups.

CONCLUSIONPresent results suggest a decreased rate of elimination of hepta congeners with aging in females, rather than a birth-generation phenomenon.

OBJECTIVES: After the Fukushima Daiichi nuclear power plant disaster in 2011, residents of Kawauchi village who experienced evacuation had a high risk of suffering from diabetes and metabolic syndrome compared with non-evacuees. In addition to evacuation, lifestyle characteristics can be important factors influencing the development and prognosis of diabetes or glucose tolerance. The current study aimed to evaluate the effects of evacuation (i.e., lifestyle changes) on the incidence of diabetes among the non-diabetic residents of Kawauchi village. METHODS: Design is retrospective cohort study. Annual health examination data of residents of Kawauchi village and control area (Ono town) in Fukushima prefecture from 2008 to 2017, as available from the Japanese National Health Insurance system. Participants were classified into three groups: "Diabetes (DM)" (FBG ≥ 126 mg/dL or HbA1c ≥ 6.5% or hospital visit for DM or usage of diabetic medication), "Borderline DM" (126 mg/dL > FBG ≥ 110 mg/dL or 6.5% > HbA1c ≥ 6.0%, and without hospital visit, and without diabetic medication), and "Normoglycemic" (FBG < 110 mg/dL and HbA1c < 6.0%, and without hospital visit, and without diabetic medication). New onset of diabetes was evaluated and the events or missing data were occurred at health checkup. For this survival analysis, 339 residents in Kawauchi and 598 residents in Ono were included. Average follow-up periods after 2010 were 3.9 years in Kawauchi village and 3.6 years in Ono town. RESULTS: Compared with the normoglycemic group, incidence of DM was much greater in the borderline DM group, where DM occurred among 38.2% of the group in 2012 and increased to over 60% cumulatively through 2017 in Kawauchi village. DM had a prevalence of 16.3% in 2012, and below 30% in 2017 in borderline DM group of Ono town. Cox proportional hazard regression analysis was applied to non-DM groups at both study sites separately to evaluate the effects of lifestyle changes at each site. While BMI, BMI change, and the lack of regular exercise (HR = 1.29, 1.72, and 5.04, respectively) showed significant associations with the onset of diabetes in Ono town, only BMI and late-night dinner (HR = 1.21 and 4.86, respectively) showed significant associations with diabetes onset in Kawauchi village. CONCLUSIONS The current results confirmed that diabetes incidence was increased 6 years after the Daiichi nuclear power plant disaster in Kawauchi. We also found changes in lifestyle habits, suggesting that diabetes prevention with promotion of healthy lifestyle behaviors is an urgent priority.
Aged ; Cohort Studies ; Diabetes Mellitus ; epidemiology ; etiology ; Female ; Fukushima Nuclear Accident ; Health Surveys ; Humans ; Incidence ; Japan ; epidemiology ; Life Style ; Male ; Middle Aged ; Retrospective Studies