[Discussion of Emissions and Health Risk of Polycyclic Aromatic Hydrocarbons (PAHs) from the Retreading Process of Waste Tires].

The emissions characteristics of 16 kinds of polycyclic aromatic hydrocarbons (PAHs) in ambient air during the waste tire retreading process (open-air storage, mixing, vulcanization, and grinding processes) and in workers' dormitory were analyzed. In addition, the occupational health risk of the workers was evaluated. Results showed that PAHs were detected in all retreading processes and in the workers' dormitory.

[Possible Sources of PCDD/Fs in Atmosphere of a Certain District in Guangdong].

This paper analyzed 17 polychlorinated dibenzo--dioxins and dibenzofurans(PCDD/Fs) by HRGC/HRMS in the flue gas of a certain municipal solid waste incinerator(MSWI) and its surrounding air and other possible sources in Guangdong. It discussed the feature of homologs and main toxic monomers in all samples. It also investigated the relationship among surrounding area, MSWI and possible sources using principle component analysis (PCA) and cluster analysis.

[Emission of PCDD/Fs from Crematories and Its Influencing Factors].

To analysis the influencing factors for the emssions of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) as structure of crematory, air pollution control device (APCD) and funeral objects, etc, we collected and measured the PCDD/Fs emissions in flue gas from 13 crematories in China. Then we proposed some supervision suggestions on measures of pollution control and management. The results indicated that the emission levels of PCDD/Fs (as the toxic equivalent concentration, TEQ) was ranged in a large gap from 0.

[Levels of PCDD/Fs and dioxin-like PCBs in soils near E-waste dismantling sites].

One hundred and fifty one soil samples from 125 sampling points were collected near E-waste dismantling sites and analyzed for polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (PCBs). Total concentration of PCDD/Fs in topsoil samples ranged from 280 pg x g(-1) to 7 010 pg x g(-1) dry weight with the mean value of 1 380 pg x g(-1) dry weight. The mean value of the second layer and the deepest layer is 63% and 38% of that of top soils, respectively.

[Effects of mechanical vibration on the morphology of the acellular scaffold for the spinal cord].

Objective: To investigate the effects of mechanical vibration on the morphology of the acellular scaffold for the spinal cord and establish a procedure to construct an acellular rat spinal cord allograft retaining intact matrix fibers for repairing spinal cord injuries.

Methods: Fifteen segments of rat spinal cord were divided randomly into 3 groups and subjected to mechanical vibration at the frequency 80 r/min (group A, n=5), 120 r/min (group B, n=5), and 160 r/min (group C, n=5) respectively. The spinal cord was treated with Triton X-100 and sodium deoxycholate at room temperature and washed with distilled water.