Low efficiency of earth kilns used in the carbonising process of wood to make charcoal has been reported as one of the sources of increasing charcoal wastes in the global south. However, the potential link and approaches of converting charcoal wastes-to-valuable energy and for the environmental health is not well known in Africa. Promoting local community capacity engagement in the production and reutilisation of recycled charcoal wastes at the households’ level is one of important measures to maintain environmental services for sustainability since households make decisions on the type of energy used. This paper, presents an approach of converting charcoal wastes to fuel energy for rural households and environmental health in Kilosa District, Tanzania. To achieve the objective of this research, the primary data were collected through interviews held with 298 randomly selected households, Focus Group Discussions and observations. IBM SPSS statistics version 20 Cross tab tools were used in the data analysis. Results revealed that the conversion of charcoal wastes-to-fuel energy approach used in this research demonstrates the ability of recyclable briquettes made from the locally available charcoal pollutants collected at different stages from earth kilns, to selling centers, improves tree harvest behaviour, adds another fuel energy source through reutilisation, and ultimate reduces pollution at the local level. Thus, the study provides a basis for policymakers to adopt charcoal wastes recycling strategies to address matters related to energy and ultimately enhances environmental health for sustainable development in Tanzania and beyond.

The aim of this study was to investigate the temporal characteristics of negative air ion concentration in the Songshan National Nature Reserve, Beijing. Hence, three typical forest stands and a nonforested land control group were selected during the growing season of May to October. The ion concentration was monitored using the Japanese COM-3200PRO negative air ion detector, and the air quality was evaluated using the amperometric air ion evaluation index method. The results showed that the diurnal variation of negative air ion concentration in the typical forest stands exhibited “double peak” curves, except for Betula dahurica forest in spring. The peak values of the annual growth season were attained between 9:00 and 11:00 as well as 16:00 and 17:00, and the trough value was attained at approximately 13:00. The monthly concentration variation characteristics in the stands showed “single peaks”, with the exception of the Juglans mandshurica forest. The negative air ion concentration was higher in July, August, and September both inside and outside the forest. The seasonal concentration variation characteristics showed that the negative air ion concentration inside and outside the forest followed the relation: summer (833±150 ion cm^-3) > autumn (735±174 ion cm^-3) > spring (632±178 ion cm^-3). From the air quality evaluation, the average CI value of the forested land was 0.75±0.26, indicating that the air was clean. The average CI value of the nonforested land was 0.31±0.04; the air quality was within an acceptable range. Overall, the concentration of each stand followed the relation: Juglans mandshurica (0.83±0.11) > Tilia mongolica (0.74±0.10) > Betula dahurica (0.67±0.13) > nonforested land (0.31±0.04). Varied forest stands have different temporal characteristics for negative air ion concentration and air quality. Using forest resources wisely, it is possible to significantly enhance the air quality in the Songshan National Nature Reserve.

China’s economic development has brought about high-speed urbanization and haze pollution problems. Large populations are concentrated in cities, which also brings air pollution, environmental problems and infectious diseases. Based on the haze pollution data of 29 capital cities in China in 2017, the geographically weighted regression method was used to investigate the relationship between urban spatial expansion (USE) and haze. The results of this study reveal some interesting phenomena. The USE in most cities has a significant positive correlation with haze pollution. The USE of cities in the Southwest Region (SW), Southern coast (SC), and Middle Reaches of the Yangtze River (MYTR) have significant positive impacts on the haze in those cities. Among them, the coefficient of spatial expansion of the SC cities is the largest at 0.438, followed by the SW at 0.4104, and finally, the MYTR at 0.296. In addition, the urban expansion of two cities in the Northern coast (NC) and the Middle reaches of the Yellow River (MYR) passed the significance test while only one city in each of the Eastern coast (EC), the Northwest region (NW), and the Northeast region (NE) passed the significance test, indicating that the impacts of the spatial expansion of these three regions on the haze pollution are minimal. The economic development of the MYR has a significant negative impact on the haze. The effect of the urban greening level on haze is significantly negative in the SC and the SW. The impacts of urban consumption expenditures on haze in the NE, SW, and MYR are also negative. These results indicate that to reduce haze pollution, different countermeasures should be taken in the different regions in China.

Green development is the coordinated development of the economy, society and environment and has become a mainstream development model. This paper evaluates the green water resource utilization efficiency (GWRUE) of 38 regions in the four-city area in central China during 2010-2019 using a super-slacks-based measure (super-SBM) DEA model considering unexpected output. Then, the spatiotemporal variations in GWRUE are analyzed by the standard deviational ellipse method, and the geographical detector method is employed to reveal the dominant impacts and interaction impacts on GWRUE spatiotemporal variations. The results show that: (1) From 2010 to 2019, the GWRUE in the four-city area in central China was low, and the difference among regions was obvious, showing a downward trend. (2) From 2010 to 2019, the spatial gravity center of GWRUE experienced a change process from northeast to southwest, and its moving speed showed a “waveform” rising trend. Moreover, the standard deviational ellipse (SDE) range of each characteristic time point showed a decreasing trend, indicating that the spatial variations in GWRUE tended to be agglomerated. (3) From 2010 to 2019, the influence of each factor on the spatial variations in GWRUE was different each year. In addition, the two-way interactions between different influencing factors were mainly manifested as bivariate enhancement relationships and nonlinear enhancement relationships and were especially affected by multiple factors that produce a nonlinear enhancement interaction. This study can provide a practical basis for realizing water ecological civilization construction and high-quality development in the four-city area in central China.