An industrial waste sludge was incinerated in a laboratory-scale fluidized-bed incinerator and sixteen priority polyaromatic hydrocarbons (PAHs), including the vaporphase PAHs adsorbed by XAD-2 and the solid-phase ones intercepted by glass fiber filters, were monitored. The experimental parameters were equivalence ratio ( φ = 0.83 and 1.25) and incinerating temperature (500, 600, 700, and 800 °C). The fuel-rich condition was carried out to resemble "fault-mode" operation. The nominal gaseous residence times were in the 0.7-1.2 second range. A gas chromatograph/flame ionization detector (GC/FID) was used to identify the PAHs qualitatively and quantitatively.Three priority PAHs-phenanthrene (PhA), fluoranthane (FluA), and pyrene (Pyr)-were detected in great quantities for all incineration runs. Two other priority PAHs-fluorene (Flu) and anthracene (AnT)-were found only in the solid phase for the fuel-rich run at 500 °C. In general, the PAH levels detected were lower for the runs at higher incineration temperatures and lower equivalence ratio.

The purpose of this study was to focus on the survey of the prevalence rate of dental trauma for Taiwanese children aged below six years. A total sample of 4,620 children was collected by stratified cluster sample design, and Probability Proportion to Size. The sample examined was 4,037 children and the completion rate was 87.38%. Training for the oral examination was provided to improve the coordination and reliability of the examiners to enhance consistency. A database was designed by Microsoft Access and data analyzed by statistics software SAS and JMP after data entry. Comparison between categorical variables was performed by using Pearson's chi-square test and between numerical variables by using t-test analysis. The prevalence rate of dental trauma to deciduous teeth for the 0-6 year-ld children was 0.94%, boys had 1.12% and girls 0.68% prevalence rate of dental trauma. There was no significant difference between boys and girls in dental trauma prevalence. The prevalence rate of dental trauma by age showed that the highest peak occurred at 3 years old (1.19%), followed by 4 (0.95%) and then 5 year-old (0.92%) children. In our study, upper central incisors occupied 0.99% prevalence of dental trauma among primary dentition. Upper lateral incisors and lower central incisors only occupied a very small prevalence rate, less than 0.05%. A low prevalence rate of dental trauma occurred to the children aged below 6 years in Taiwan, which may be caused by different study and sampling method, different definition of dental trauma, and different care attitude of parents to children. Considering the high frequency of dental trauma in the 3-5 year-old children, the safety of kindergartens and the prevention of dental trauma to deciduous teeth should be considered.

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