Ecological risk assessment of heavy metals in desulfurized seawater discharged from a coal-fired power plant in Qingdao.

Despite the prevalence of discharge of large volumes of heavy-metal-bearing seawater from coal-fired power plants into adjacent seas, studies on the associated ecological risks remain limited. This study continuously monitored concentrations of seven heavy metals (i.e. As, Cd, Cr, Cu, Hg, Pb, and Zn) in surface seawater near the outfall of a coal-fired power plant in Qingdao, China over three years. The results showed average concentrations of As, Cd, Cr, Cu, Hg, Pb, and Zn of 2.63, 0.33, 2.97, 4.63, 0.008, 0.85, and 25.00 µg/L, respectively. Given the lack of data on metal toxicity to local species, this study investigated species composition and biomass near discharge outfalls and constructed species sensitivity distribution (SSD) curves with biological flora characteristics. Hazardous concentrations for 5% of species (HC5) for As, Cd, Cr, Cu, Hg, Pb, and Zn derived from SSDs constructed from chronic toxicity data for native species were 3.23, 2.22, 0.06, 2.83, 0.66, 4.70, and 11.07 µg/L, respectively. This study further assessed ecological risk of heavy metals by applying the Hazard Quotient (HQ) and Joint Probability Curve (JPC) based on long-term heavy metal exposure data and chronic toxicity data for local species. The results revealed acceptable levels of ecological risk for As, Cd, Hg, and Pb, but unacceptable levels for Cr, Cu, and Zn. The order of studied heavy metals in terms of ecological risk was Cr > Cu ≈ Zn > As > Cd ≈ Pb > Hg. The results of this study can guide the assessment of ecological risk at heavy metal contaminated sites characterized by relatively low heavy metal concentrations and high discharge volumes, such as receiving waters of coal-fired power plant effluents.

Study on Life Satisfaction of the Elderly Based on Healthy Aging.

The life satisfaction of the elderly is the key to subjective well-being and healthy aging. Many related studies are focused on the affected factors, including health status, economic level, social support, pension mode, social security, and intergenerational support, etc., but few are based on the macro perspective of healthy aging. This study constructed a healthy aging evaluation system with 6 dimensions, including 15 primary indicators and 57 secondary indicators, to evaluate the relationship between healthy aging and elderly life satisfaction. Results showed that the 13168 participants were, mainly, female (53.76%), 80-99 years old (47.99%), lived in rural areas (77.00%), married and living with their spouse (43.70%), and widowed (52.15%). 80.32% lived with household members. 70.37% elderly were satisfied with their lives. Specifically, there was no gender difference in life satisfaction of the elderly (p=0.273), but there were significant differences between groups of urban and rural (p < 0.001), age groups of 65-79 and 80 older (p < 0.001), marriage groups of unmarried and married (p < 0.001), and types of elderly care of living alone and with others (p < 0.001), respectively. Among the six dimensions of healthy aging, healthcare performed best and living environment dimension was the worst, which was an area that urgently needed to strengthen. The odds ratios (ORs) showed that the dimensions of social participation/social equity and economic finance played important roles in the well-being of the elderly. Under the macro background of healthy aging, how to take measures from the micro perspective of the healthy aging evaluation index system and ultimately improve the life satisfaction of the elderly and still needs to be explored in-depth.

Accuracy of soft tissue balancing in total knee arthroplasty using surgeon-defined assessment versus a gap-balancer or electronic sensor.

BACKGROUND: Soft tissue balancing is essential for the success of total knee arthroplasty (TKA) and is mainly dependent on surgeon-defined assessment (SDA) or a gap-balancer (GB). However, an electronic sensor has been developed to objectively measure the gap pressure. This study aimed to evaluate the accuracy of soft tissue balancing using SDA and GB compared with a sensor. METHODS: Forty-eight patients undergoing TKA (60 knees) were prospectively enrolled. Soft tissue balancing was sequentially performed using SDA, a GB, and an electronic sensor. We compared the SDA, GB, and sensor data to calculate the sensitivity, specificity, and accuracy at 0°, 45°, 90°, and 120° flexion. Cumulative summation (CUSUM) analysis was performed to assess the surgeon's performance during the sensor introductory phase. RESULTS: The sensitivity of SDA was 63.3%, 68.3%, 80.0%, and 80.0% at 0°, 45°, 90°, and 120°, respectively. The accuracy of the GB compared with sensor data was 76.7% and 71.7% at 0° and 90°, respectively. Cohen's kappa coefficient for the accuracy of the GB was 0.406 at 0° (moderate agreement) and 0.227 at 90° (fair agreement). The CUSUM 0° line achieved good prior performance at case 45, CUSUM 90° and 120° showed a trend toward good prior performance, while CUSUM 45° reached poor prior performance at case 8. CONCLUSION: SDA was a poor predictor of knee balance. GB improved the accuracy of soft tissue balancing, but was still less accurate than the sensor, particularly for unbalanced knees. SDA improved with ongoing use of the sensor, except at 45° flexion.

Probabilistic ecological risk assessment of heavy metals in western Laizhou Bay, Shandong Province, China.

Considering the serious land-based pollution and the weak water exchange ability of western Laizhou Bay, it is essential to conduct an ecological risk assessment of the pollutants in this area. In this study, the ecological risk caused by heavy metals deposited in the surface sediments and those resuspended in the seawater of western Laizhou Bay was evaluated using probabilistic approaches. First, the concentrations of seven heavy metals, namely As, Cd, Cr, Cu, Hg, Pb, and Zn, in the surface sediments and seawater of western Laizhou Bay were detected during the spring and autumn of 2016. The concentrations of As, Cd, Cr, Cu, and Pb were found to be at levels comparable to those in the other global coastal systems, while those of Hg and Zn were lower than those in other coastal areas. Next, an ecological risk assessment of heavy metals in the surface sediments was performed using a typical potential ecological risk index and refined by using a Monte Carlo simulation. The results suggested low risk for the heavy metals detected in the sediments of western Laizhou Bay, with the exception of Hg in September 2016, which showed a probability (0.03%) of moderate risk. Meanwhile, the aquatic ecological risk assessment of the heavy metals was performed by applying a combination of hazard quotient (HQ) and joint probability curve. While the ecological risk of Cd, Hg, and Pb was found to be acceptable, the HQs for Cr, Cu, and Zn were greater than 1, and the overall risk probability of their adverse effects was higher than 0.05, suggesting certain ecological risk. Specifically, in the case of As, the overall risk probability was lower than 0.05, suggesting that its ecological risk was acceptable, although its HQ was greater than 1. Thus, by applying the probabilistic approaches, the ecological risk of the heavy metals in western Laizhou Bay was better characterized in this study, avoiding both overestimation and underestimation of ecological risk.

Hydrogel-Encapsulated Enzyme Facilitates Colorimetric Acute Toxicity Assessment of Heavy Metal Ions.

Conventional analysis of heavy metal ions in water requires highly skilled staff and sophisticated equipment. These limitations make conventional approaches difficult to perform analysis on-site without delay. Herein, we report a facile colorimetric sensing system developed for acute toxicity assessment of heavy metal ions. A bioactive enzyme, ß-galactosidase, was used as sensing agent rather than bacteria or other higher organisms to improve selectivity and response time. The developed bioassay is capable of assessing the toxicity of heavy metal ions such as Hg(II), Cd(II), Pb(II), and Cu(II). The effects of enzyme concentration on the assessing performances (i.e., sensitivity and response time) of bioassay were explored and illustrated. Generally, low enzyme concentration facilitates sensitivity enhancement, achieving a 50% inhibiting concentration (IC50) of 0.76 µM (=152 ppb) Hg(II), and high enzyme concentration ensures quick response, enabling a response time down to 9 min. Moreover, the enzyme and substrate were respectively encapsulated by hydrogel to further simplify the assay procedure and enhance the stability of the enzyme. The hydrogel-encapsulated enzyme worked well even when heated up to 60 °C and retained ca. 90% activity after storage for 5 months. Moreover, the developed toxicity-assessing system is feasible for assessing toxicity of actual water samples. This assay approach is low cost and time effective and has no potential ethic issues. In addition, this work paves the way for the development of toxicity assessment kits for on-site analysis based on functional bioactive molecules.

A quantitative risk-assessment system (QR-AS) evaluating operation safety of Organic Rankine Cycle using flammable mixture working fluid.

Mixture of hydrocarbon and carbon dioxide shows excellent cycle performance in Organic Rankine Cycle (ORC) used for engine waste heat recovery, but the unavoidable leakage in practical application is a threat for safety due to its flammability. In this work, a quantitative risk assessment system (QR-AS) is established aiming at providing a general method of risk assessment for flammable working fluid leakage. The QR-AS covers three main aspects: analysis of concentration distribution based on CFD simulations, explosive risk assessment based on the TNT equivalent method and risk mitigation based on evaluation results. A typical case of propane/carbon dioxide mixture leaking from ORC is investigated to illustrate the application of QR-AS. According to the assessment results, proper ventilation speed, safe mixture ratio and location of gas-detecting devices have been proposed to guarantee the security in case of leakage. The results revealed that this presented QR-AS was reliable for the practical application and the evaluation results could provide valuable guidance for the design of mitigation measures to improve the safe performance of ORC system.

Thyroid disruption in male goldfish (Carassius auratus) exposed to leachate from a municipal waste treatment plant: Assessment combining chemical analysis and in vivo bioassay.

Several classes of thyroid-disrupting chemicals (TDCs) have been found in refuse leachate, but the potential impacts of leachate on the thyroid cascade of aquatic organisms are yet not known. In this study, we chemically analyzed frequently reported TDCs, as well as conducted a bioassay, to evaluate the potential thyroid-disrupting effects of leachate. We used radioimmunoassay to determine the effects of leachate exposure on plasma 3,3',5-triiodo-l-thyronine (T3), 3,3',5,5'-l-thyroxine (T4), and thyroid-stimulating hormone (TSH) levels in adult male goldfish (Carassius auratus). We also investigated the impacts of leachate treatment on hepatic and gonadal deiodinases [types I (D1), II (D2), and III (D3)] and gonadal thyroid receptor (TRα-1 and TRß) mRNA expressions by using real-time polymerase chain reaction. The results indicated the presence of five TDCs (bisphenol A, 4-t-octylphenol, di-n-butyl phthalate, di-n-octyl phthalate, and diethylhexyl phthalate); their mean concentrations in the leachate were 18.11, 2.76, 4.86, 0.21, and 9.16 µg/L, respectively. Leachate exposure induced plasma T3 and TSH levels in male fish, without influencing the plasma T4 levels. The highly elevated D2 mRNA levels in the liver were speculated to be the primary reason for the induction of plasma T3 levels. Disruption of thyroid functions by leachate was also suggested by the up-regulation of D1 and D2 as well as TRα-1 mRNA levels in the gonads. Prominent thyroid disruptions despite the very low TDC concentrations in the exposure media used in the bioassay strongly indicated the existence of unidentified TDCs in the leachate. Our study indicated the necessity of conducting in vivo bioassays to detect thyroid dysfunctions caused by leachate.

Non-carcinogenic risk assessment of eight metals in the source groundwater of Shaying River basin.

Because of serious pollution of river water, people living along the Shaying River in China exploit the groundwater as a drinking water resource. Various pollutants including heavy metals have been detected in the groundwater at depths up to 200 m. To perform a non-carcinogenic risk assessment, the hazard index (HI) was determined for several metals present in the groundwater. High resolution inductively coupled plasma-mass spectrometry and inductively coupled plasma-atomic emission spectroscopy were used to measure the levels of Hg, Fe, Mn, Zn, Cd, Cr, Cu and Pb in source groundwater of eight tap water treatment plants (WTPs) during a 3-year period (2007-2009). Zn was present at the highest concentration of up to 101.2 µg l(-1) and Cd contributed the most (57.8%) to the HI in the WTPs, followed by Mn (14.3%) and Cr (13.1%). Both hazard quotients of individual metals and HI of total non-carcinogenic risk in each WTP were below 1.0, suggesting that the water posed negligible health risk on local residents. Temporal and spatial comparisons showed that high HIs tend to occur in low water periods (i.e., summer), and the City Pressure Station (Fuyang City) had the highest HI, followed by Yingnan Pressure Station (Yingnan Country) and Taihe WTP (Taihe Country). This study provides benchmark information useful for regulatory authorities to control the discharge of metals into the Shaying River Basin, and serves as a basis for comparison to other river systems in the world.

Economic burden of epilepsy in a developing country: a retrospective cost analysis in China.

PURPOSE: To study the cost of epilepsy in China, and, therefore, provide essential information on the burden of the disease to individuals and society. METHODS: A cost-of-illness study was performed on a retrospective cohort of medically treated patients. Data on clinical characteristics, utilization of sources, and costs were collected from 289 patients in a standardized format. RESULTS: Direct medical care costs was Chinese yuan, renminbi (RMB) 2,529 (USD 372) per year per patient, of which antiepileptic drugs (RMB 1,651 or USD 243) accounted for the major cost component. Nonmedical direct costs were much less than direct health care costs, averaging approximately RMB 756 (USD 111). Costs due to loss of productivity averaged approximately RMB 1,968 (USD 289) per patient per year. Taken together, the overall mean annual cost for epilepsy per patient in our series was approximately RMB 5,253 (USD 773), and these costs accounted for more than half of the mean annual income. Total cost was significantly associated with disease severity and different responses to drug treatment. In addition, new antiepileptic drugs and the number of drugs taken were closely related with the drug cost. CONCLUSION: The results indicate that the economic burden of epilepsy to both Chinese patients and the nation is heavy, and the composition proportions of the costs in China have many similar features and some noteworthy differences with that of other countries.