Evaluation on production trend, compositions, and impact of plastic waste in Chengdu, southwestern China.

Based on statistical data from 2005 to 2019, we used the back propagation (BP) neural network model to predict the production amount of plastic waste in Chengdu. In addition to the amount of waste produced we wanted to achieve an understanding of its composition and environmental impacts. Compositions of plastic waste were analyzed by sampling. Particulate matter in the air and greenhouse gas emissions (GHGs) from plastic waste incineration, bisphenol A (BPA) from plastic waste landfills, were also evaluated. Results indicated that (a) economic development, urban construction level, and residents' consumption were pusitively correlated to different degrees to plastic waste production; (b) the production of plastic waste in Chengdu in 2025 and 2030 will reach 865.3 and 931 kilotons (Kt), respectively; (c) high density polyethylene (HDPE) and polypropylene (PP) are the two main components of plastic waste in Chengdu and accounted for 40.17% and 24.96%, respectively; (d) different degrees of environmental impacts occurred during plastic waste incineration and landfill (taking 2019 as an example, the incineration of plastic waste in Chengdu produced between 2874.82 and 4711.73 tons of inhalable particulate matter (PM) and emitted between 725.4 and 867.4 Kt of CO2, and between 65.02 and 910.27 kg of bisphenol A (BPA) leached from sanitary landfills); (e) positive policies and measures from the beginning to the end-of-life of plastics should be carried out in the future, which would improve the level of plastic waste management in Chengdu and mitigate the side-impacts from plastic waste treatment and disposal.Implications: The implications of this article are Generation trends of plastic waste were revealed by a BP neural network model, which provided essential data for authorities to make decisions on waste management.Influencing factors affecting plastic waste generation were analyzed, which will strongly support policy considerations regarding plastic waste control.This investigation first explored and reported the compositions of plastic waste mixed with municipal solid waste (MSW), which yielded valuable information concerning plastic waste and details concerning the impacts of plastic waste disposal processes.Those results of this investigation, being published here for the first time, will guide plastic waste management in Chengdu and could also provide useful information to other cities regarding that issue.

Hepatectomy for patients with alveolar echinococcosis: Long-term follow-up observations of 144 cases.

BACKGROUND: Western China is a region in which alveolar echinococcosis (AE) is endemic. Few studies and comparisons have evaluated the outcomes of AE patients after hepatectomy, and no strategy has been defined for the treatment of AE patients with unresectable tumors. This study sought to assess the outcomes of AE patients after hepatectomy at a tertiary referral center. PATIENTS AND METHODS: We retrospectively analyzed data from 144 patients with hepatic AE who were treated via hepatectomy at our center between January 2004 and December 2015. Patients' overall survival (OS), progression-free survival (PFS), and risk factors were analyzed, and Kaplan-Meier survival curves were constructed. Patient age, year of initial treatment, PNM stage, and risk factors were entered as co-variates in a Cox regression modle that was used for analysis. RESULTS: Hepatectomy was performed in 144 patients diagnosed with hepatic AE (84 complete resections and 60 reduction surgeries). In the complete resection group, the 5- and 10-year OS rates were both 97.6%, and the 5- and 10-year PFS rates were both 97.9%. In the reduction surgery group, the 5-, and 10-year OS rates were 89.7% and 73.4%, respectively, and the 5-, and 10-year PFS rates were 78.1% and 69.5%, respectively. Patients in the complete group had better OS prognoses and PFS than patients in the reduction surgery group (P = 0.018 and P = 0.001). Multivariate analysis indicated that curability and portal vein invasion are independent factors associated with PFS (P = 0.028 and P = 0.006). CONCLUSIONS: The most effective therapy for AE is complete resection. Reduction surgery does not appear to offer obvious advantages over benzimidazole therapy alone in the treatment of AE. Curability and portal vein invasion are independent prognostic factors for PFS in a multivariate analysis.