Carbon Trading in China Reduces the Dependence of Household Waste Electrical and Electronic Equipment Recycling on Government Subsidies.

China's enterprises of waste electrical and electronic equipment (WEEE) recycling suffer from low profitability that is highly dependent on government subsidies. This low economic gain impedes the sustainable growth of China's WEEE-recycling sector and also adds to the government's financial burden. Prior life-cycle studies have approved the carbon reduction potentials or net carbon credit of recycling WEEE. However, policymakers fail to know whether the revenue from selling carbon credits can offset the government's financial subsidy. We performed life-cycle and cost-benefit analyses for a case recycling enterprise that processes six categories of household appliances. The results show that the reduction potentials of greenhouse gases range from 930-3450 kgCO2e by recycling per ton of household appliances and materials substitution. The recycling enterprise would gain extra revenue ranging from 32 to 160 RMB per ton of appliance if the carbon credits were sold at China's current carbon price, i.e., 45-60 RMB tCO2e-1. Recycling waste refrigerators exhibits the highest carbon revenue, offsetting 6-17% of the government's financial subsidy. Microcomputers, by contrast, indicate the lowest carbon revenue, equivalent to 1-3% of its highest government subsidy. For each household appliance category, when the carbon price reaches 270-600 RMB tCO2e-1, selling carbon credits can fully offset the government's financial subsidy. Constrained by the processing capacity of the case enterprise, optimizations for appliance-recycling composition contribute a 15-25% profit growth to the current economic gains. Interpreting the specific profit depends on the predefined scenarios of carbon price and the substitution rate of the regenerated materials for the virginal ones. Our findings show that raising the profitability of WEEE recycling enterprises through the carbon trading policy contributes to the sustainable growth of China's WEEE-recycling sector while alleviating the government's financial burden.

Genetic substructure analysis of three isolated populations in southwest China.

Southwest China is home to numerous ethnic minorities, as well as many geographically and genetically isolated groups. However, the genetic substructure of these ethnic groups, especially the paternal genetic structure between groups, has not been comprehensively analyzed. In this study, we used Y chromosome capture and Illumina sequencing technologies to investigate the paternal genetic structure of three isolated groups of male unrelated individuals, including Baima in Pingwu, Sichuan Province, Muya in Shimian, Sichuan Province, and Kongge in Jinghong, Yunnan Province. We calculated the frequencies of related haplogroups by the fixed-point compound amplification method and direct counting method, and used the Past3.0 software to perform principal component analysis to draw a population clustering tree. we observed that Kongge had 3 Y chromosome haplogroups, Baima had 4 Y chromosome haplogroups, and Muya had 5 Y chromosome haplogroups. The results showed that Kongge was most closely related to the Wa, and the Y chromosome types of the Baima and Muya were mainly concentrated in the D haplogroup and its lower reaches. It has the closest relationship with the Tibetans in Qamdo and Nyingchi. The study on the genetic structure of different ethnic groups has enriched the genetic relationship of isolated populations and provided a new perspective for understanding Chinese ethnic groups.

Toxic footprint and materials profile of electronic components in printed circuit boards.

Waste printed circuit boards (WPCBs) contain valuable material resources and hazardous substances, thereby posing a challenge for sustainable resource recovery and environmental protection initiatives. Overcoming this challenge will require mapping the toxic footprint of WPCBs to specific materials and substances used in manufacturing electronic components (ECs). Therefore, this work collected 50 EC specimens from WPCBs in five ubiquitous consumer products, such as television, refrigerator, air conditioner, washing machine and computer. The work extracted and analyzed metal contents and used leachability assessments based on tests adopted by the regulatory policies from China and the United States. The work found that copper and iron are the most abundant constituents in ECs, with concentrations ranging 5.90-796.62 g/kg and 0-831.53 g/kg, respectively; whereas abundance of precious metal content is in the order of silver > gold > palladium > platinum, with silver concentration ranging 15-5290 mg/kg. The content of marginally-regulated toxic substance arsenic ranged 0-9700 mg/kg; whereas fully regulated toxic metals such as chromium, lead and mercury did not exceed the thresholds set by China and US standards. The work found new toxic threats from arsenic and selenium leached from 20 of 50 ECs exceeding regulatory standards. These results will aid manufacturers and recyclers in protecting workers' health and environmental quality from arsenic and selenium pollution, and should initiate discussion about regulating these toxic components as part of a comprehensive program to reduce the toxic footprint of electronic products.

Enhanced leaching of manganese from low-grade pyrolusite using ball milling and electric field.

In this study, electric field and ball milling were used to leach Mn2+ from low-grade pyrolusite (LGP). The effects of current density, reaction time, reaction temperature, ball-to-powder weight ratio, and ball milling time on the leaching efficiency of Mn2+ from LGP as well as the leaching mechanism were systematically studied. The results showed that the combined use of electric field and ball milling enhanced the leaching of Mn2+ from LGP. The leaching efficiency of Mn2+ reached 97.79% under the optimum conditions of LGP-to-pyrite mass ratio of 1:0.18, current density of 30 mA/cm2, LGP-to-H2SO4 mass ratio of 1:0.4, liquid-to-solid ratio of 5:1, ball-to-powder weight ratio of 1:1, ball milling time of 2 h, temperature of 80 °C, and leaching duration of 120 min. This value was 25.95% higher than that attained without ball milling and 41.45% higher than that attained when neither ball milling nor electric field was employed. Pyrite was fully oxidized to generate additional SO42- and Fe3+, and was further hydrolyzed to form jarosite (KFe3(SO4)2(OH)6) and hydronium jarosite (Fe3(SO4)2(OH)5·2H2O) via ball milling and electric field application. Moreover, the electric field changed the surface charge distribution of the mineral particles and promoted collisions between them as well as the collapse of the crystal lattice, further improving the leaching efficiency of Mn2+ from LGP. This study provided a new method for leaching Mn from LGP.

Chilling Prospect: Climate Change Effects of Mismanaged Refrigerants in China.

The global community has responded to the dual threats of ozone depletion and climate change from refrigerant emissions (e.g., chlorofluorocarbons, CFCs, and hydrofluorocarbons, HFCs) in refrigerators and air conditioners (RACs) by agreeing to phase out the production of the most damaging chemicals and replacing them with substitutes. Since these refrigerants are "banked" in products during their service life, they will continue to impact our environment for decades to come if they are released due to mismanagement at the end of life. Addressing such long-term impacts of refrigerants requires a dynamic understanding of the RACs' life cycle, which was largely overlooked in previous studies. Based on field surveys and a dynamic model, we reveal the lingering ozone depletion potential (ODP) and significant global warming potential (GWP) of scrap refrigerants in China, the world's largest producer (62%) and consumer (46%) of RACs in 2015, which comes almost entirely from air conditioners rather than refrigerators. If the use and waste management of RACs continue with the current trend, the total GWP of scrap refrigerants in China will peak by 2025 at a level of 135.2 ± 18.9 Mt CO2e (equal to approximately 1.2% ± 0.2% of China's total greenhouse gas emissions or the national total of either The Netherlands and Czech Republic in 2015). Our results imply an urgent need for improving the recycling and waste management of RACs in China.

Estimation of stature by using the dimensions of the right hand and right foot in Han Chinese adults.

The Han Chinese people are the main ethnic group in China and the largest ethnic group in the world. The dimensions of the hands and feet have been successfully used for the estimation of stature. A total of 26,927 healthy adult subjects, comprising 13,221 men and 13,706 women, were recruited. The survey samples were chosen through random cluster sampling. The mean values were significantly higher in men than those in women for all measurements (P<0.001). All the measurements showed a statistically significant correlation with stature (P<0.01). The combination of the right hand length and the right foot length was the best predictor of stature because it had the lowest standard error of estimate. The use of multiple regression equations yielded better results than did the use of linear regression equations. The accuracy of stature prediction ranged from ±4.81 to ±6.39 cm. The present study was of great importance with regards to improving the physical anthropology database of ethnic groups in China.

Area-level socioeconomic disparities impact adult overweight and obesity risks of Han ethnicity in China.

OBJECTIVES: The profound socioeconomic processes occurring in developing countries have been accompanied by the notable increase of overweight and obese populations. This study for the first time investigates the impact of area-based socioeconomic status (SES) on adult overweight and obesity for both sexes of Han ethnicity in China. METHODS: We investigated 6,221 adult participants of Han ethnicity from 18 geographic areas in China, and measured stature and weight for each participant. The mean annual income per individual was chosen as the area-level SES index. We adopted logistic regression analysis to explore the relationship of area-level SES with overweight and obesity. RESULTS: The age-adjusted overweight and obesity prevalence was 32.46% for men and 29.27% for women respectively. Substantial area-level SES disparity in overweight and obesity risks for both sexes exist in China. The overweight and obesity prevalence rates increased with increasing SES levels in men rather than in women. CONCLUSION: Men living in high SES areas as well as women living at the lowest SES areas were most likely to be at the highest risk of overweight and obesity in China.

Digit ratio (2D:4D) and handgrip strength in Hani ethnicity.

INTRODUCTION: The ratio of the length of the second finger to the fourth finger (2D:4D) in humans is considered as a putative marker of prenatal exposure to testosterone, and has been progressively adopted as one useful tool to evaluate the effect of prenatal hormones in some traits such as physical ability. Handgrip strength is one authentic measure of physical ability and is generally used on the anthropological research within an evolutionary viewpoint. METHODS: Here we present the first evidence on 2D:4D and handgrip strength on adult participants of Hani ethnicity and explore the relationship between digit ratio (2D:4D) and handgrip strength. We examined 2D:4D and handgrip strength of 80 males and 60 females at Bubeng village, in the Yunnan province of China. RESULTS: The mean 2D:4D in females was higher than that in males for each hand. Females showed significantly higher 2D:4D than males in the right hand rather than in the left hand. Males displayed significantly higher handgrip strength than females for both hands. Handgrip strength decreased with age for both sexes. A significant negative correlation between 2D:4D and handgrip strength was found in the right hand of males. CONCLUSION: The relationship between 2D:4D and handgrip strength may be attributed to evolutionary drive of sexual selection operating on fetal programming.

Brief communication: Body mass index, body adiposity index, and percent body fat in Asians.

Human obesity is a growing epidemic throughout the world. Body mass index (BMI) is commonly used as a good indicator of obesity. Body adiposity index (BAI = hip circumference (cm)/stature (m)(1.5) - 18), as a new surrogate measure, has been proposed recently as an alternative to BMI. This study, for the first time, compares BMI and BAI for predicting percent body fat (PBF; estimated from skinfolds) in a sample of 302 Buryat adults (148 men and 154 women) living in China. The BMI and BAI were strongly correlated with PBF in both men and women. The correlation coefficient between BMI and PBF was higher than that between BAI and PBF for both sexes. For the linear regression analysis, BMI better predicted PBF in both men and women; the variation around the regression lines for each sex was greater for BAI comparisons. For the receiver operating characteristic (ROC) analysis, the area under the ROC curve for BMI was higher than that for BAI for each sex, which suggests that the discriminatory capacity of the BMI is higher than the one of BAI. Taken together, we conclude that BMI is a more reliable indicator of PBF derived from skinfold thickness in adult Buryats.

Regional or global WEEE recycling. Where to go?

If we consider Waste Electrical and Electronic Equipment (WEEE) management, we can see the development of different positions in developed and developing countries. This development started with the movement of WEEE from developed countries to the developing countries. However, when the consequences for health and the environment were observed, some developing countries introduced a ban on the import of this kind of waste under the umbrella of the Basel Convention, while some developed countries have been considering a regional or global WEEE recycling approach. This paper explores the current movements between Source and Destination countries, or the importers and exporters, and examines whether it is legal and why illegal traffic is still rife; how global initiatives could support a global WEEE management scheme; the recycling characteristics of the source an destination countries and also to ascertain whether the principle of Extended Producer Responsibility (EPR) has been established between the different stakeholders involved in WEEE management. Ultimately, the Full Extended Producer Responsibility is presented as a possible solution because the compensation of the environmental capacity for WEEE recycling or treatment could be made by the contribution of extra responsibility; and also generating an uniform standard for processing WEEE in an environmentally sound manner could support the regional or international solution of WEEE and also improve the performance of the informal sector.

Digit ratio (2D:4D) and handgrip strength in subjects of Han ethnicity: impact of sex and age.

The ratio of the length of the second finger to the fourth finger (2D:4D) is considered to be a putative proxy of prenatal exposure to testosterone, and has been increasingly used as a promising tool to evaluate the impact of prenatal androgenization in humans in such traits as physical performance. In this study, for the first time, we present 2D:4D data on adult participants of Han ethnicity. We consider the sexual dimorphism of 2D:4D and handgrip strength, and also report the relationship between 2D:4D and handgrip strength of males and females. The sample consisted of 54 males and 55 females recruited from a remote village in the Qinling Mountains, China. We found sexual dimorphism of both 2D:4D and handgrip strength, i.e., males had lower 2D:4D and right-left 2D:4D than females and greater handgrip strength than females. There was a sex-specific correlation between 2D:4D and handgrip strength, i.e., 2D:4D in the right hand was negatively correlated with handgrip strength in males but not in females. This relationship may be driven by sexual selection operating on fetal programming.

Interfacial and mechanical property analysis of waste printed circuit boards subject to thermal shock.

Waste printed circuit boards (PCBs) are the focal points for handling electric and electronic waste. In this paper, a thermal shock method was used to pretreat waste PCBs for the improvement of crushing performance. The influence of the thermal shock process on interfacial modification and mechanical property attenuation of PCB waste was studied. The appearance and layer spacing of the basal plane began to change slightly when the temperature reached 200 degrees C. By 250 degrees C, apparent bulging, cracking, and delamination were observed. However, pyrolysis of PCBs occurred when the temperature reached 275 degrees C, where PCBs were carbonized. The thermogravimetric analysis of PCB particles under vacuum showed that 270 degrees C was the starting point of pyrolysis. The tensile and impact strength of PCBs were reduced as shock temperature rose gradually, with a reduction by 2.6 and 16.5%, respectively, at 250 degrees C from its unheated strength. The PCBs that were heated to 250 degrees C achieved 100% liberation, increasing linearly from 13.6% for unheated PCBs through a single-level shear-crusher (2-mm mesh) and resulting in an obvious reduction of 9.5% (dB) in dust and noise at 250 degrees C. These parameters could be helpful for establishing the operational setup for industrial-scale facilities with the aim of achieving a compact process and a highly efficient recovery for waste PCBs compared with those of the traditional combination mechanical technologies.