The study investigated the age-adjusted mortality rate and disease odds among deceased residents living in areas exposed to wastewater and cleanwater from 2007 to 2011, in Shijiazhuang, China. Mortality data for eight villages exposed to wastewater and 16 villages not exposed to wastewater were collected and crosschecked from multiple sources. Overall mean age-adjusted mortality rate for wastewater areas was 798/105 (95% Confidence Interval (CI) = ± 68), insignificantly higher than the mean mortality rate for cleanwater area, 726/105 (95% CI = ± 46), p > 0.05. Malignant neoplasms and respiratory mortality and disease odds were higher in wastewater areas than in cleanwater areas, OR = 1.7 (95% CI = 1.3-2.2, p < 0.01) and OR = 1.9 (95% CI = 1.1-3.4, p < 0.05), respectively. Wastewater area mortality and disease odds for Lung and Stomach cancers after adjustments were OR = 1.6 (95% CI = 1.1-2.4, p < 0.05) and OR = 1.8 (95% CI = 1.2-2.7, p < 0.01), respectively, significantly higher than those of cleanwater areas. There is a possibility that exposure to wastewater might be associated with cancer and respiratory disease mortality. The study recommends that the use of wastewater be limited, discouraged, or discontinued.

The collision between satellites IRIDIUM 33 and COSMOS 2251 indicated that the clash of two on-orbit satellites was becoming an inevitable reality. Our calculation with the two-line orbit element by NORAD showed that some two geostationary satellites had approached very close in July 2009. Therefore, more attention should be given to avoid such collisions. This paper analyzes the orbital long-term variation of a dead satellite drifting in the geostationary orbit. Also, the negative effects posed by dead satellites upon the on-orbit operational geostationary satellites are studied. Then the paper proposes a novel idea to launch a satellite sweeper whose purpose is to collect the on-orbit dead satellites and help them de-orbit to a "graveyard". The satellite sweeper consists of a parent satellite and a child satellite. The child satellite collects a dead satellite and transfers it to a higher orbit. The parent satellite stationed in the geostationary orbit is in charge of refueling the child satellite. The strategy of maneuver and rendezvous is presented and a series of formulas are derived. The analysis results show that our method to clean the geostationary orbital zone is practical and fuel-saving. With the help of just a few satellite sweepers, we can gain a clean environment of geostationary orbit environment again. satellite sweeper, geostationary orbit, dead satellite, de-orbit, rendezvous Citation:Li Y H, Yang K Z, Shan C S, et al. A preliminary study on dead geostationary satellite removal.

No abstract

Based on the four types of SAR images from Envisat, Radarsat-2, and TerraSAR-X between 2007 and 2019, a linear time-series analysis of Coherence Targets method is employed to acquire the 13year deformation velocity and cumulative deformation maps of the Beijing Plain. Such measurement firstly provides the annual subsidence rate and spatial evolution characteristics of the subsidence areas and the maximum subsidence rates in Laiguangying-Ciqu, which is the largest subsidence area of the Beijing Plain, were beyond 14 cm/year from 2009 to 2018. We correlate the observed subsidence with land use, Quaternary strata and pre-existing faults to assess the driving mechanisms of land subsidence. We find that large-scale land subsidence or patchy subsidence in the Beijing Plain takes on a similar variation to dry land and rural settlements/manufacturing enterprise land use. We also observe that the subsiding areas are mainly distributed in the edge of Alluvial-Proluval Fan or in the lacustrine or swampy sediments among Alluvial-Proluval Fans with much thicker compressible deposits, and the high subsidence gradients orientate along active faults. Therefore, this research could contribute to propose effective control measures for subsidence and ground fissure and achieve better hazard mitigation programme in Beijing.