Estimation of indoor soil/dust-skin adherence factors and health risks for adults and children in two typical cities in southern China.

Soil/dust (SD) skin adherence is key dermal exposure parameter used for calculating the health risk of dermal exposure to contaminants. However, few studies of this parameter have been conducted in Chinese populations. In this study, forearm SD samples were randomly collected using the wipe method from population in two typical cities in southern China as well as office staff in a fixed indoor environment. SD samples from the corresponding areas were also sampled. The wipes and SD were analyzed for tracer elements (aluminum, barium, manganese, titanium, and vanadium). The SD-skin adherence factors were 14.31 µg/cm2 for adults in Changzhou, 7.25 µg/cm2 for adults in Shantou, and 9.37 µg/cm2 for children in Shantou, respectively. Further, the recommended values for indoor SD-skin adherence factors for adults and children in Southern China were calculated to be 11.50 µg/cm2 and 9.37 µg/cm2, respectively, which were lower than the U.S. Environmental Protection Agency (USEPA) recommended values. And the SD-skin adherence factor value for the office staff was small (1.79 µg/cm2), but the data were more stable. In addition, PBDEs and PCBs in dust samples from industrial and residential area in Shantou were also determined, and health risks were assessed using the dermal exposure parameters measured in this study. None of the organic pollutants posed a health risk to adults and children via dermal contact. These studies emphasized the importance of localized dermal exposure parameters, and further studies should be conducted in the future.

Emission inventories, emission factors, and composition profiles of volatile organic compounds (VOCs) and heavy metals (HMs) from an e-waste dismantling park in southern China.

Electronic waste (e-waste) dismantling is a significant source of atmospheric pollutants, including volatile organic compounds (VOCs) and heavy metals (HMs), which may have adverse effects on the surrounding environment and residents. However, the organized emission inventories and emission characteristics of VOCs and HMs from e-waste dismantling are not well documented. In this study, the concentrations and components of VOCs and HMs were monitored at the exhaust gas treatment facility from two process areas of a typical e-waste dismantling park in southern China in 2021. Emission inventories of VOCs and HMs were established, with total emissions of 8.85 t/a and 18.3 kg/a for VOCs and HMs in this park, respectively. The cutting & crushing (CC) area was the largest emissions source, accounting for 82.6% of VOCs and 79.9% of HMs, respectively, while the baking plate (BP) area had higher emission factors. Additionally, the concentration and composition of VOCs and HMs in the park were also analyzed. For VOCs, the concentrations of halogenated hydrocarbons and aromatic hydrocarbons were comparable in the park, while m/p-xylene, o-xylene, and chlorobenzene were the key VOC species. The HM concentrations followed the order of Pb > Cu > Mn > Ni > As > Cd > Hg, with Pb and Cu being the main heavy metals released. This is the first VOC and HM emission inventory for the e-waste dismantling park, and our data will lay a solid ground for pollution control and management for the e-waste dismantling industry.

Identifying the implementation effect of technology transfer policy using system dynamics: a case study in Liaoning, China.

Given that technology transfer provides an important boost for promoting national economic development, technology transfer policy (TTP) has attracted more and more attention from academia and industry. The government issued many policies. However, the implementation effect of TTP still needs to be clarified. This study is carried out from the progressive level of "text content-influence path-implementation effect.'' It aims to adopt a systematic analysis method to analyze policy tools and policy implementation stages, then builds a conceptual framework of the influence path of TTP. Then the relationship between variables in the qualitative model was clarified, and the system dynamics (SD) model was used to build a quantitative model with four feedback loops. Finally, taking Liaoning, China as an example, the system simulation and sensitivity analysis of the main parameters are implemented in Vensim PLE. Different policy tools have different roles in the TTP impact stages of research, transfer, and industrialization. Based on the data of 2013-1019, the SD model constructed in this paper can be used to predict the implementation effect of TTP during 2020-2015. Simulation and sensitivity analysis results provide practical enlightenment for government departments to improve the implementation effect of the existing TTP. This study also provides other researchers with a systematic understanding for improving the implementation effect of TTP with a "text content-influence path-implementation effect" conduction chain and provides new insights for further research on TTP.

[Biodegradable plastic production by activated sludge with different carbon sources].

Polyhydroxyalkanoates(PHAs) are polyesters synthesized by numerous bacteria in sludge as intracellular carbon and energy storage compounds under the condition of unbalance growth. Another important aspect of PHAs is thermoplastic polyester with the remarkable characteristics of biodegradability. In this paper, using sodium acetate, sodium propionate and sodium butyrate as the unique carbon source, 5.58%, 3.90% and 4.98% PHAs of dry sludge weight were obtained by assimilated sludge as PHAs synthesis strains in the anaerobic condition, and 12.32%, 9.55% and 11.35% PHAs of dry sludge weight were obtained in the anaerobic condition. It was shown that there were large quantities strains which could accumulate PHAs as granules in the cytoplasm of cells, and the yield of PHAs in the anaerobic process were higher than that in the aerobic process. The best result was that 12.32% PHAs of dry sludge weight was obtained in the best experiment condition, and the yield of the PHAs to substrate was 30.65%. The structures of PHAs were analyzed by 1HNMR spectrum, and the relationship of the structure of PHAs and the carbon source was explained.