Abnormal prion protein deposits with high seeding activities in the skeletal muscle, femoral nerve, and scalp of an autopsied case of sporadic Creutzfeldt-Jakob disease.

We report the general autopsy findings of abnormal prion protein (PrP) deposits with their seeding activities, as assessed by the real-time quaking-induced conversion (RT-QuIC) method, in a 72-year-old female patient with sporadic Creutzfeldt-Jakob disease (sCJD). At 68 years of age, she presented with gait disturbance and visual disorders. Electroencephalography showed periodic synchronous discharge. Myoclonus was also observed. A genetic test revealed that PRNP codon 129 was methionine/methionine (MM). She died of pneumonia three years and four months after disease onset, and a general autopsy was performed. The brain weighed 650 g and appeared markedly atrophic. Immunohistochemistry for PrP revealed synaptic PrP deposits and coarse PrP deposits in the cerebral cortices, basal ganglia, cerebellum, and brainstem. Western blot analysis identified type 1 proteinase-K-resistant PrP in frontal cortex samples. PrP deposits were also observed in systemic organs, including the femoral nerve, psoas major muscle, abdominal skin, adrenal medulla, zona reticularis of the adrenal gland, islet cells of the pancreas, and thyroid gland. The RT-QuIC method revealed positive seeding activities in all examined organs, including the frontal cortex, femoral nerve, psoas major muscle, scalp, abdominal skin, adrenal gland, pancreas, and thyroid gland. The following 50% seeding dose (SD50 ) values were 9.5 (frontal cortex); 8 ± 0.53 (femoral nerve); 7 ± 0.53 (psoas major muscle); and 7.88 ± 0.17 (scalp). The SD50 values for the adrenal gland, dermis, pancreas, and thyroid gland were 6.12 ± 0.53, 5.25, 4.75, and 4.5, respectively. PrP deposits in general organs may be associated with long-term disease duration. This case indicated the necessity for general autopsies in sCJD cases to establish strict infection control procedures for surgical treatment and to examine certain organs.

Emission factors and composition of PM2.5 from laboratory combustion of five Western Australian vegetation types.

This study investigated the emission of PM10 and PM2.5 (particulates with diameters of less than 10 µm and 2.5 µm, respectively) and the chemical composition of PM2.5 from laboratory combustion of five Australian vegetation types (three grasslands, a woodland and a forest). A mix of plants representative of Banksia (woodland) and Jarrah (forest) and three types of grasses (Spinifex - Triodia basedowii; Kimberley grass - Sehima nervosum and Heteropogon contortus; and an invasive grass (Veldt) - Ehrharta calycina) were burnt in 9 combustion conditions comprised of 3 fuel moisture levels (dry, moist, wet) and 3 air flow rates (no, low and high flow). PM (particulate matter) samples were collected onto filters and measured using gravimetric analysis. PM2.5 was then extracted and analyzed for water-soluble metals and polycyclic aromatic hydrocarbons (PAH) concentrations. The largest proportion of PM10 (98%) from vegetation fires was PM2.5. Banksia yielded the highest PM2.5 emission factor (EF), followed by Jarrah and Spinifex. Veldt grass combustion generated significantly higher emissions of PM2.5 compared with the other two grass types. High moisture contents and flow rates resulted in larger emissions of PM2.5. A strong correlation (R2 = 0.84) was observed between the EF for PM2.5 and combustion efficiency, suggesting higher PM emission with lower combustion efficiencies. Potassium and sodium were the most abundant PM2.5-bound water soluble metals, accounting for more than 97% of the total mass of metals analyzed. PAHs were found in significant concentrations, including the carcinogenic benzo(a)pyrene. Pyrene and fluoranthene were the most abundant PAHs detected, accounting for nearly 40% mass of the total PAHs. Indeno(1,2,3-cd)pyrene and benzo(g,h,i)perylene ratio (IND/IND + BghiP) appeared to be produced in a diagnostic ratio that indicated that the PAHs were derived from vegetation fires rather than other sources of emissions. The EF for PM2.5 and its chemical composition (water-soluble metals and PAHs) were strongly influenced by the type of vegetation burned. The results presented in this study could be useful in predicting the risks of human health effects on firefighters and the public who may be exposed to regular bushfires in Australia.

In vitro assessment of the toxicity of bushfire emissions: A review.

Bushfires produce many toxic pollutants and the smoke has been shown to have negative effects on human health, especially to the respiratory system. Bushfires are predicted to increase in size and frequency, leading to a greater incidence of smoke and impacts. While there are many epidemiological studies of the potential impact on populations, there are few studies using in vitro methods to investigate the biological effects of bushfire emissions to better understand its toxicity and significance. This review focused on the literature pertaining to in vitro toxicity testing to determine the state of knowledge on current methods and findings on the impacts of bushfire smoke. There was a considerable variation in the experimental conditions, outcomes and test concentrations used by researchers using in vitro methods. Of the studies reviewed, most reported adverse impacts of particulate matter (PM) on cytotoxic and genotoxic responses. Studies on whole smoke were rare. Finer primary particulates from bushfire smoke were generally found to be more toxic than the coarse particulates and the toxicological endpoints of bushfire PM different to ambient PM. However the variation in study designs and experimental conditions made comparisons difficult. This review highlights the need for standard protocols to enable appropriate comparisons between studies to be undertaken including the assessment of physiologically relevant outcomes. Further work is essential to establish the effect of burning different vegetation types and combustion conditions on the toxicity of bushfire emissions to better inform both health and response agencies on the significance of smoke from bushfires.

Effects of road characteristics on distribution and toxicity of polycyclic aromatic hydrocarbons in urban road dust of Ulsan, Korea.

Comparisons between concentration, size effect, molecular distribution, and toxicity of polycyclic aromatic hydrocarbons (PAHs) in urban road dust of Ulsan, Korea, were carried out. The road dust was collected at eleven representative urban sites offering unique road characteristics. The road dust was separated into four size categories as follows: 850-2000 microm, 180-850 microm, 75-180 microm and less than 75 microm. PAHs in the categorized road dust were ultrasonically extracted by a mixture of dichloromethane and n-hexane (1:1) for 30 min. Sixteen PAHs were specifically identified by a high performance liquid chromatography method. Pavement type, traffic volume, vehicle speed and surrounding environment of the study roads greatly affected the overall PAH road dust concentration. The molecular distribution of PAHs was strongly affected by vehicle type, surrounding area and pavement type of road. When the road dust particle size decreased, the total concentration of PAHs increased. The existence of coarse asphalt particles due to the abrasion of new asphalt pavement at some sites could increase the total PAH concentration to a size of 180-850 microm. PAHs in road dust were also evaluated for toxicity using the reported toxicity equivalency factors. The toxicity of PAHs in road dust showed a strong correlation to the total PAH concentration (r(2)=0.955). However, the coefficients of determination (r(2)) for the sizes of 850-2000 microm, 180-850 microm, 75-180 microm and less than 75 microm were 0.966, 0.998, 0.707 and 0.514, respectively.

Analysis of potential RDF resources from solid waste and their energy values in the largest industrial city of Korea.

The production potential of refuse derived fuel (RDF) in the largest industrial city of Korea is discussed. The purpose of this study is to evaluate the energy potential of the RDF obtained from utilizing combustible solid waste as a fuel resource. The total amount of generated solid waste in the industrial city was more than 3.3 million tonnes, which is equivalent to 3.0tonnes per capita in a single year. The highest amount of solid waste was generated in the city district with the largest population and the biggest petrochemical industrial complex (IC) in Korea. Industrial waste accounted for 89% of the total amount of the solid waste in the city. Potential RDF resources based on combustible solid wastes including wastepaper, wood, rubber, plastic, synthetic resins and industrial sludge were identified. The amount of combustible solid waste that can be used to produce RDF was 635,552tonnes/yr, consisting of three types of RDF: 116,083tonnes/yr of RDF-MS (RDF from municipal solid waste); 146,621tonnes/yr of RDF-IMC (RDF from industrial, municipal and construction wastes); and 372,848tonnes/yr of RDF-IS (RDF from industrial sludge). The total obtainable energy value from the RDF resources in the industrial city was more than 2,240,000x10(6)kcal/yr, with the following proportions: RDF-MS of 25.6%, RDF-IMC of 43.5%, and RDF-IS of 30.9%. If 50% or 100% of the RDF resources are utilized as fuel resources, the industrial city can save approximately 17.6% and 35.2%, respectively, of the current total disposal costs.

Characteristics, toxicity, and source apportionment of polycylic aromatic hydrocarbons (PAHs) in road dust of Ulsan, Korea.

This study identified concentrations, molecular distributions, toxicities, and sources of polycylic aromatic hydrocarbons (PAHs) in road dust from different areas of Ulsan, the largest industrial city in Korea. The total PAH concentrations in industrial areas were dependent on industrial emissions and vehicular exhaust, while those in urban areas were mainly dependent on traffic density, sampling site location, and accumulation of pollutants or road dust. The PAH concentration of each particle size group increased with decreasing particle size. This may be because of the higher surface area available for deposition or coating of PAHs in road dust with smaller particle sizes. The molecular distributions of PAHs among the sites in the petrochemical area and heavy traffic area were similar because of the similarities in their emission sources. The toxic equivalent concentrations (TEQs) of PAHs in the road dust ranged from 0.93 microg/g to 16.74 microg/g in industrial areas and from 4.37 microg/g to 68.84 microg/g in urban areas. The correlation coefficient of total PAH concentration and TEQ in urban areas was 0.98, which was much higher than that in industrial areas where it was 0.75. Principal component analysis showed that PAHs in road dust from Ulsan originate from four main sources: diesel vehicular emissions, oil combustion, gasoline vehicular emissions, and coal combustion.