Health risk assessment of heavy metal(loid)s in road dust via dermal exposure pathway from a low latitude plateau provincial capital city: The importance of toxicological verification.

The human health risk assessment through the dermal exposure of metal (loid)s in dust from low latitude and high geological background plateau cities was largely unknown. In this study, the road dust samples were harvested from a typical low-latitude plateau provincial capital city Kunming, Southwest China. The total concentration and dermal bioaccessibility of heavy metal (loid)s in road dust were determined, and their health risks as well as cytotoxicity on human skin keratinocytes were also assessed. The average concentrations of As (28.5 mg/kg), Cd (2.65 mg/kg), Mn (671 mg/kg), and Zn (511 mg/kg) exceeded the soil background values. Arsenic had the highest bioaccessibility after 2 h (3.79%), 8 h (4.24%), and 24 h (16.6%) extraction. The dermal pathway when bioaccessibility is considered has a higher hazard quotient than the conventional method using total metal(loid)s in the dust. In addition, toxicological verification suggested that the dust extracts suppressed the cell viability, increased the reactive oxygen species (ROS) level and DNA damage, and eventually activated the mitochondria-mediated apoptosis pathway, evidenced by the upregulation of Caspase-3/9, Bax, and Bak-1. Cadmium was positively correlated with the mRNA expression of Bax. Taken together, our data indicated that both dermal bioaccessibility and cytotoxicity should be considered for accurate human skin health risk assessment of heavy metal(loid)s in road dust, which may provide new insight for accurate human health risk assessment and environmental management.

Assessment of Right Atrial Function Measured with Cardiac MRI Feature Tracking for Predicting Outcomes in Patients with Dilated Cardiomyopathy.

Background Right atrial (RA) function strain is increasingly acknowledged as an important predictor of adverse events in patients with diverse cardiovascular conditions. However, the prognostic value of RA strain in patients with dilated cardiomyopathy (DCM) remains uncertain. Purpose To evaluate the prognostic value of RA strain derived from cardiac MRI (CMR) feature tracking (FT) in patients with DCM. Materials and Methods This multicenter, retrospective study included consecutive adult patients with DCM who underwent CMR between June 2010 and May 2022. RA strain parameters were obtained using CMR FT. The primary end points were sudden or cardiac death or heart transplant. Cox regression analysis was used to determine the association of variables with outcomes. Incremental prognostic value was evaluated using C indexes and likelihood ratio tests. Results A total of 526 patients with DCM (mean age, 51 years ± 15 [SD]; 381 male) were included. During a median follow-up of 41 months, 79 patients with DCM reached the primary end points. At univariable analysis, RA conduit strain was associated with the primary end points (hazard ratio [HR], 0.82 [95% CI: 0.76, 0.87]; P < .001). In multivariable Cox analysis, RA conduit strain was an independent predictor for the primary end points (HR, 0.83 [95% CI: 0.77, 0.90]; P < .001). A model combining RA conduit strain with other clinical and conventional imaging risk factors (C statistic, 0.80; likelihood ratio, 92.54) showed improved discrimination and calibration for the primary end points compared with models with clinical variables (C statistic, 0.71; likelihood ratio, 37.12; both P < .001) or clinical and imaging variables (C statistic, 0.75; likelihood ratio, 64.69; both P < .001). Conclusion CMR FT-derived RA conduit strain was an independent predictor of adverse outcomes among patients with DCM, providing incremental prognostic value when combined in a model with clinical and conventional CMR risk factors. Published under a CC BY 4.0 license. Supplemental material is available for this article.

Comprehensive assessment of river ecological environment in nature reserve based on TOPSIS combined with grey correlation method.

The main driving factors of river ecological environment were analyzed to reveal the response mechanism of river ecosystem to ecological environmental factors. The results showed that the driving factors of river water quality were resistivity, COD and reoxidation potential, the driving factors of soil environment along river banks were total phosphorus, total nitrogen and pH, and the driving factors of plant nutrition along river banks were total potassium and total nitrogen. The contribution rates of water quality, soil and plant to river ecological environment health were 43, 51 and 70%, respectively. The comprehensive ecological environment of Menghuo River, Gongyihai, Arulendi River, Yiniu River, Dahonggou River and Nanya River is superior to each other, with the comprehensive proximity index of 0.6258, 0.5908, 0.5524, 0.5265, 0.5195 and 0.3889, respectively. Each detection index can accurately and truly invert the ecological environment health status of rivers in the protected areas.

Cost-effectiveness analysis of sintilimab plus IBI305 versus sorafenib for unresectable hepatic cell carcinoma in China.

BACKGROUND: Sintilimab combined with IBI305 treatment regimen had potential clinical benefits than sorafenib in the first-line treatment of patients with unresectable hepatic cell carcinoma (HCC). However, whether sintilimab plus IBI305 has economic benefits in China remains unclear. METHODS: From the perspective of Chinese payers, we used the Markov model to simulate patients with HCC receiving treatment with sintilimab plus IBI305 and sorafenib. The transition probability between health states was estimated using the parametric survival model, and the cumulative medical costs and utility of the two treatment methods were estimated. Considering the incremental cost-effectiveness ratios (ICERs) as the evaluation index, sensitivity analyses were performed to explore the impact of uncertainty on the results. RESULTS: Compared to sorafenib, sintilimab plus IBI305 generated an additional $17552.17 and 0.33 quality-adjusted life years, resulting in an ICER of $52817.89. The analysis outcomes were most sensitive to the total cost of sintilimab plus IBI305. With a willingness-to-pay threshold of $38,334, sintilimab plus IBI305 showed a 1.28% probability of being cost-effective. The total cost of sintilimab plus IBI305 should be reduced by at least 31.9% to be accepted by Chinese payers. CONCLUSIONS: Regardless of whether the price of sintilimab plus IBI305 and sorafenib is covered by Medicare, sintilimab plus IBI305 is unlikely to be cost-effective for first-line treatment of patients with unresectable HCC.

Expectancy-Value Motivation and Physical Activity- and Health-Related Outcomes among At-Risk Children and Adolescents.

Despite a large amount of research having been done to examine and promote physical activity and health among adolescents and children, relatively little attention has been paid attention to underrepresented populations. In this study, we investigated the relationships between expectancy-value motivation and physical activity- and health-related outcomes among a group of at-risk boys at a summer sports camp. The total participants included 107 boys (Mage = 11.78 years, SD = 1.20). The boys' perceived expectancy beliefs (EXP), importance (IMP), interest (INT), usefulness (USE), effort (EFT), and intention for future participation (IFP) were assessed using established questions on a five-point Likert scale, and a PACER test was performed to estimate their cardiovascular fitness (CVF). Through a path analysis, we found that EXP positively predicted CVF (ß = 0.19, p < 0.01), IMP positively predicted EFT (ß = 0.26, p < 0.01), and INT positively predicted both EFT (ß = 0.34, p < 0.01) and IFP (ß = 0.28, p < 0.01), while USE had no statistically significant effect on either EFT, IFP, or CVF. We discussed the limitations and implications of the present study. We recommend including a diverse sample and employing the expectancy-value model in future research, and advocating expectancy beliefs and task values, especially importance and interest, among participants during physical activity promotion.

Are high-risk heavy metal(loid)s contaminated vegetables detrimental to human health? A study of incorporating bioaccessibility and toxicity into accurate health risk assessment.

Heavy metal(loid)s in the environment threaten food safety and human health. Health risk assessment of vegetables based on total or bioaccessible heavy metal(loid)s was widely used but can overestimate their risks, so exploring accurate methods is urgent for food safety evaluation and management. In this study, a total of 224 frequently consumed vegetables and their corresponding grown soils were collected from Yunnan, Southwest China. The total contents and bioaccessibilities of heavy metal(loid)s in vegetables were measured, their health risks were evaluated using the non-carcinogenic and carcinogenic risk models provided by USEPA. Besides, the gastrotoxicity of high-risk vegetables was also evaluated using a human cell model. Results showed that 6.25-43.8 % of Cr, Cd, and Pb contents in Zea mays L., Coriandrum sativum L., or Allium sativum L. exceeded the maximum permissible level of China, which were not consistent with those in corresponding soils. The bioaccessibility of Cr, Cd, As, Pb, Cu, Zn, Ni, and Mn in vegetables in the gastric phase was 0.41-93.8 %. Health risks based on bioaccessibility were remarkably decreased compared with total heavy metal(loid)s, but the unacceptable carcinogenic risk (CR > 10-4) was found even considering the bioaccessibility. Interestingly, gastric digesta of high-risk vegetables did not trigger adverse effects on human gastric mucosa epithelial cells, indicating existing health risk assessment model should be adjusted by toxic data to accurately reflect its hazards. Taken together, both bioaccessibility and toxicity of heavy metal(loid)s in vegetables should be considered in accurate health risk assessment and food safety-related policy-making and management.

Refining health risk assessment of arsenic in wild edible boletus from typical high geochemical background areas: The role of As species, bioavailability, and enterotoxicity.

Arsenic (As) is easily accumulated in wild Boletus. However, the accurate health risks and adverse effects of As on humans were largely unknown. In this study, we analyzed the total concentration, bioavailability, and speciation of As in dried wild boletus from some typical high geochemical background areas using an in vitro digestion/Caco-2 model. The health risk assessment, enterotoxicity, and risk prevention strategy after consumption of As-contaminated wild Boletus were further investigated. The results showed that the average concentration of As was 3.41-95.87 mg/kg dw, being 1.29-56.3 folds of the Chinese food safety standard limit. DMA and MMA were the dominant chemical forms in raw and cooked boletus, while their total (3.76-281 mg/kg) and bioaccessible (0.69-153 mg/kg) concentrations decreased to 0.05-9.27 mg/kg and 0.01-2.38 mg/kg after cooking. The EDI value of total As was higher than the WHO/FAO limit value, while the bioaccessible or bioavailable EDI suggested no health risks. However, the intestinal extracts of raw wild boletus triggered cytotoxicity, inflammation, cell apoptosis, and DNA damage in Caco-2 cells, indicating existing health risk assessment models based on total, bioaccessible, or bioavailable As may be not accurate enough. Given that, the bioavailability, species, and cytotoxicity should be systematically considered in accurate risk assessment. In addition, cooking mitigated the enterotoxicity along with decreasing the total and bioavailable DMA and MMA in wild boletus, suggesting that cooking could be a simple and effective way to decrease the health risks of consumption of As-contaminated wild boletus.

Heavy metal(loid)s in agriculture soils, rice, and wheat across China: Status assessment and spatiotemporal analysis.

Heavy metal(loid)s (HMs) accumulation in agricultural soils, rice, and wheat is of particular concern in China, while the status and spatio-temporal distribution of HMs in the soil-crops system have been rarely reported at the national scale. This study aimed to summarize the overall pollution status, spatiotemporal patterns, and drivers of HMs in agricultural soil, rice, and wheat nationwide. The metal-polluted data from 1030 agricultural soils, rice, and wheat in China were collected from the literature published from 2000 to 2022. The results showed that Cd was the most prevailing contaminant in soils based on its spatiotemporal distribution and accumulation. The pollution cases and severe pollution percentage of Cd (103 %) and Hg (128 %) show an increasing trend pattern. Mining activities are the main anthropogenic sources of agricultural soil HMs in China. Cd and Pb had the highest exceedance rate in rice (33.5 and 32.2 %) and wheat (25.8 and 30.3 %). The rice from Hunan, Fujian, and Guangxi showed the highest average concentration of Cd and Pb, respectively, while wheat samples from Hubei had the greatest exceedance rate of Pb. Besides, HMs in crops was not usually corresponding to soil HMs but increased gradually from north to south areas. Several mitigation strategies and accurate health risk assessments model of HMs based on bioavailability were also proposed and recommended. Collectively, this review provides valuable information to improve the management of farmland nationwide, optimize the accurate risk assessment, and reduce HMs pollution.

Cost-effectiveness analysis of pembrolizumab plus chemotherapy versus chemotherapy as the first-line treatment for advanced esophageal cancer.

OBJECTIVE: The KEYNOTE-590 trial showed that individuals with advanced esophageal cancer who received Pembrolizumab in combination with chemotherapy as a first-line regimen achieved a significant extension of survival. However, this treatment option increases the financial burden on patients and the economic benefits remain to be further evaluated. METHODS: A Markov model was used to simulate 10-year survival of patients with esophageal cancer from the perspective of United States (US) Medicare payers. We evaluated the economics of Pembrolizumab plus chemotherapy in the PD-L1 positive score (CPS ≥10) and any PD-L1 expression groups, respectively. We estimated total costs, quality-adjusted life years (QALYs), and calculated incremental cost effectiveness ratios (ICERs). Sensitivity analyses were conducted to explore the impact of uncertainties on the results. Subgroup analysis was also performed. RESULTS: The analysis results showed that the ICER for pembrolizumab plus chemotherapy versus chemotherapy alone was $293,513.17/QALYs in the any PD-L1 expression group. This exceeded the threshold of willingness to pay ($150,000/QALYs). ICERs were most sensitive to the cost of pembrolizumab and the ICERs exceeded $150,000/QALYs in all subgroups. CONCLUSIONS: Evidence suggests that first-line pembrolizumab in combination with chemotherapy is not a cost-effective option for advanced esophageal cancer in the US, regardless of PD-L1 expression status.

Total and bioaccessible heavy metals in cabbage from major producing cities in Southwest China: health risk assessment and cytotoxicity.

Green leafy vegetables are economical and nutritious, but they may be contaminated with heavy metals. In this study, we assessed the total and bioaccessible concentrations of As, Cd, Pb and Cr in a popular vegetable cabbage (Brassica oleracea) from four major producing cities in Yunnan, Southwest China. With the mean concentrations of As, Cd, Pb and Cr being 0.24, 0.20, 0.32 and 1.28 mg kg-1, the As, Cd and Pb concentrations were within the limits of 0.2-0.5 mg kg-1 based on Chinese National Standards and the WHO/FAO, but Cr concentration was 2.6-times greater than the limit of 0.5 mg kg-1. Based on an in vitro bioaccessibility assay of the Solubility Bioaccessibility Research Consortium (SBRC), As bioaccessibility was the lowest at 11% while those of Cd, Pb and Cr were much greater at 68-87%. The estimated daily intake (EDI) of metals through cabbage ingestion was similar for children and adults. Among the four metals, only Cr's EDI at 2.29-1.87 exceeded 1 based on total and bioaccessible concentrations. The high Cr concentration at 1.28 mg kg-1 coupled with its high bioaccessibility at 67.5% makes Cr of concern in cabbage. However, human gastrointestinal cells exposed to the gastric digesta with high bioaccessible heavy metals and risky EDI, showed no obvious cytotoxicity, indicating that existing models based on total or bioaccessible heavy metals may overestimate their human health risk. Taken together, to accurately assess the human health risk of heavy metals in cabbage, both total/bioaccessible concentrations and the gastrointestinal cell responses should be considered.

Dynamic Evaluation Indices in Spatial Learning and Memory of Rat Vascular Dementia in the Morris Water Maze.

The Morris water maze (MWM) is widely used to evaluate rodent spatial learning and memory. However, current evaluation measures are not comprehensive because there is a wide distribution in the measured response. Utilizing the graph cognition hypothesis, we proposed four new deviation indices to evaluate cognitive function in the MWM that compared the optimal swim track to the actual track taken. These include the sum of the lateral deviation vectors, the sum of the offset angles, the sum of the correction vectors, and the sum of the lateral deviation vectors to the initial optimal route. We compared the four new deviation indices to the classically used escape latency measures in a vascular dementia model and demonstrated a higher consistency in the normal distribution between the vascular dementia group and the control rats. Further, the new measures displayed higher sensitivity and specificity compared to what escape latency displayed in the Monte Carlo simulation. From the receiver operating characteristic curve, the diagnostic values of the new deviation indices are higher than those of escape latency. Therefore, including these new evaluation indices in MWM experiments provided a more effective analysis of cognitive function compared to using escape latency.

TCR Repertoire as a Novel Indicator for Immune Monitoring and Prognosis Assessment of Patients With Cervical Cancer.

There is increasing evidence that deep sequencing-based T cell repertoire can sever as a biomarker of immune response in cancer patients; however, the characteristics of T cell repertoire including diversity and similarity, as well as its prognostic significance in patients with cervical cancer (CC) remain unknown. In this study, we applied a high throughput T cell receptor (TCR) sequencing method to characterize the T cell repertoires of peripheral blood samples from 25 CC patients, 30 cervical intraepithelial neoplasia (CIN) patients and 20 healthy women for understanding the immune alterations during the cervix carcinogenesis. In addition, we also explored the signatures of TCR repertoires in the cervical tumor tissues and paired sentinel lymph nodes from 16 CC patients and their potential value in predicting the prognosis of patients. Our results revealed that the diversity of circulating TCR repertoire gradually decreased during the cervix carcinogenesis and progression, but the circulating TCR repertoires in CC patients were more similar to CIN patients than healthy women. Interestingly, several clonotypes uniquely detected in CC patients tended to share similar CDR3 motifs, which differed from those observed in CIN patients. In addition, the TCR repertoire diversity in sentinel lymphatic nodes from CC patients was higher than in tumor tissues. More importantly, less clonotypes in TCR repertoire of sentinel lymphatic node was associated with the poor prognosis of the patients. Overall, our findings suggested that TCR repertoire might be a potential indicator of immune monitoring and a biomarker for predicting the prognosis of CC patients. Although functional studies of T cell populations are clearly required, this study have expanded our understanding of T cell immunity during the development of CC and provided an experimental basis for further studies on its pathogenesis and immunotherapy.

Organophosphorus flame retardants and phthalate esters in indoor dust from different microenvironments: Bioaccessibility and risk assessment.

Incidental ingestion of indoor dust is an important pathway for human exposure to organophosphorus flame retardants (OPFRs) and phthalate esters (PAEs). However, little is known about their bioaccessibility in indoor dust. In this study, indoor dust samples were collected from houses, offices, public microenvironments (PMEs), and university dorms, and physiologically based extraction test (PBET) was used to measure the bioaccessibility of OPFRs and PAEs in these dust samples. Total concentrations of OPFRs in dust samples ranged from 0.01 to 63.2 µg g(-1), with significantly lower concentrations in dorm dust (median = 0.30 µg g(-1)) than those in houses (3.12), offices (5.94), and PMEs (11.6). Total PAEs ranged from 5.49 to 2161 µg g(-1) with significantly lower concentrations in dorm dust (379 µg g(-1)) than those in the other three types of dust (767, 515, and 731 µg g(-1)). When subject to PBET, the bioaccessibility of OPFRs ranged from 8.18% (triphenyl phosphate) to 54.5% (Tris(2-chloroisopropyl) phosphate) for OPFRs, and from 1.21% (di-2-ethylhexyl phthalate, DEHP) to 81.1% (dimethyl phthalate) for PAEs. Estimated exposure doses for adults and infants to OPFRs via dust ingestion were much lower than the reference doses (RfD), but intake dose of DEHP for infants was higher than the RfD of 20 µg kg(-1) d(-1). However, the DEHP intake dose did not exceed the RfD after incorporating bioaccessibility into risk assessment. Our data indicated the importance of considering contaminant bioaccessibility during risk assessment of indoor dust.

[Effect of water storage and aquaculture on Oncomelania hupensis control in tidal flats wetlands of islet-beach type area of Dantu section of lower reaches of Yangtze River].

OBJECTIVE: To evaluate the effect and the benefits of the projects of water storage and aquaculture on Oncomelania hupensis snail control in the tidal flats wetlands of islet-beach type area of lower reaches of the Yangtze River. METHODS: The projects of water storage and aquaculture on 0. hupensis snail control were implemented in the tidal flats wetlands of islet-beach type of lower reaches of the Yangtze River. The breed situation of the snails was investigated by the conventional method before and after the project implementation and the effect of control and elimination of the snails by the projects were evaluated. At the same time, the cost-benefit analysis of two projects among them was performed by the static benefit-cost ratio method. RESULTS: All of 0. hupensis snails were eliminated in the first year after the implementation of seven water storage and aquaculture projects. The costs of detection and control of snails saved by each project was 69.20 thousand yuan a year on average. The annual net benefits of the "Nanhao Group 10 beach" project and "Wutao Group 6-14 beach" project were 2 039.40 thousand yuan and 955.00 thousand yuan respectively, and the annual net benefit-cost ratios were 1.09: 1 and 1.07: 1 respectively. CONCLUSION: The O. hupensis snails could be rapidly eliminated by the water storage and aquaculture, and the economic benefit is obvious, but the wetland ecological protection and flood control safety should be considered in the tidal flats wetlands of islet-beach type area of lower reaches of the Yangtze River.

[Residues and health risk assessment of sulfonamides in sediment and fish from typical marine aquaculture regions of Guangdong Province, China].

Concentrations of sulfonamides including sulfadiazine (SDZ), sulfadimidin (SM2) and sulfamethoxazole (SMX) in sediments, muscle and liver tissues of 7 kinds of fish species collected from two marine aquaculture regions along the coast of Guangdong Provice were determined by high performance liquid chromatography (HPLC) equipped with a ultraviolet detector. Assessment of the health risks were conducted based on the values of maximum residue limits (MRL) and acceptable daily intake (ADI). The results showed that sulfonamides were found in all the sediment samples. The concentrations (dry wet) ranged from 2.1 - 35.2 ng x g(-1), the detected frequency of the 3 sulfonamide antibiotics ranked as SDZ (85.7%) > SM2 (71.4%) > SMX (28.6%). The detection rate of sulfonamides in samples from Daya Bay was higher than that from Hailing Island. Higher concentrations were detected in liver tissues rather than in muscle tissues (P < 0.05). The residues of SDZ, SM2 and SMX in fish muscle tissues (wet weight) ranged from 11.6-37.9, 16.3-27.8 and 4.9-20.0 ng x g(-1), respectively. The calculated daily intakes of sulfonamides in the present study ranged from 3.37-36.72 ng x kg(-1), which accounted for 0.007% -0.073% of the ADI (50 microg x kg(-1)). Health risks to human body were negligible as the estimated intake was less than 1% ADI, therefore the security of dietary was high.

Arsenic contamination in the freshwater fish ponds of Pearl River Delta: bioaccumulation and health risk assessment.

This study investigated the extent of arsenic (As) contamination in five common species of freshwater fish (northern snakehead [Channa argus], mandrarin fish [Siniperca chuatsi], largemouth bass [Lepomis macrochirous], bighead carp [Aristichthys nobilis] and grass carp [Ctenopharyngodon idellus]) and their associated fish pond sediments collected from 18 freshwater fish ponds around the Pearl River Delta (PRD). The total As concentrations detected in fish muscle and sediment in freshwater ponds around the PRD were 0.05-3.01 mg kg(-1) wet weight (w. wt) and 8.41-22.76 mg kg(-1) dry weight (d. wt), respectively. In addition, the As content was positively correlated (p < 0.05) to total organic carbon (TOC) contents in sediments. Biota sediment accumulation factor (BSAF) showed that omnivorous fish and zooplankton accumulated higher concentrations of heavy metals from the sediment than carnivorous fish. In addition, feeding habits of fish also influence As accumulation in different fish species. In this study, two typical food chains of the aquaculture ponds were selected for investigation: (1) omnivorous food chain (zooplankton, grass carp and bighead carp) and (2) predatory food chain (zooplankton, mud carp and mandarin fish). Significant linear relationships were obtained between log As and δ (15)N. The slope of the regression (-0.066 and -0.078) of the log transformed As concentrations and δ (15)N values, as biomagnifications power, indicated there was no magnification or diminution of As from lower trophic levels (zooplankton) to fish in the aquaculture ponds. Consumption of largemouth bass, northern snakehead and bighead carp might impose health risks of Hong Kong residents consuming these fish to the local population, due to the fact that its cancer risk (CR) value exceeded the upper limit of the acceptable risk levels (10(-4)) stipulated by the USEPA.

[Distribution of heavy metals in waters and pollution assessment in thallium contaminated area of Yunfu, Guangdong].

Distribution of Thallium(T1), Cadmium( Cd), Chromium (Cr), Lead (Pb), Nickel (Ni), Arsenic (As), Copper (Cu), Zinc (Zn) in water and sediments of Yunfu pyrite mine area was studied. The environmental risk assessment was conducted systematically using Sediment Quality Guidelines (SQGs) and Hakanson potential ecological risk index. The results indicated that concentration range of Tl in stream water was 0.19-65.25 microg/L, which is higher than the environmental quality standards for surface water. Concentration ranges of Tl, Zn, As, Cd, Pb in sediments were 5.89-63.0 mg/kg, 1215-5754 mg/kg, 208.4-1327 mg/kg, 4.20-17.5 mg/kg, 282-13,770 mg/kg. According to Sediments Quality Guidelines, sediments was moderately to severe level of pollution since concentrations of Tl, Cd, Cr, Pb, Ni, As, Cu, Zn were much higher than LEL (lowest effect level) values, and the concentrations of Pb, As, Zn were higher than SEL (severe effect level) values, the others were partly higher than SEL values, which may result in severe negative biota effects in the watersheds. Compared to soil background values of Guangdong province, the metals in stream sediment showed strong to severe strong ecological risk, and the ecological risk of heavy metals in the descending order of Tl, Cd, As, Pb, Cr, Ni, Zn and Cu. Besides, the sediments were severe contained by toxic element thallium and cadmium. Besides, the mainly ecological risk of heavy metal is thallium. More emphasis should be placed on thallium and cadmium control and disposal in

Effortful persistence and body mass as predictors of running achievement in children and youth: a longitudinal study.

BACKGROUND: Schools often include running in their physical education and health curriculum to increase physical activity and reduce childhood overweight. But having students run around may not be enough to sustain physical activity habits if motivational factors are not well understood. This study examined effortful persistence as a predictor of running. METHODS: Participants were 246 5th graders, and data on their demographic information, body mass index (BMI), effortful persistence, and time to complete a 1-mile run were collected across 4 years. RESULTS: Between 5th to 8th grades, effortful persistence predicted time to complete a 1-mile run even when BMI was taken into account at every grade except for 7th grade. Rank-order stability was found in major variables across-time, but no across-time prediction was found for effortful persistence on a 1-mile run. CONCLUSIONS: Lack of longitudinal predictions bodes well for interventions aimed at increasing physical activity, because children or youth with high BMIs or low effortful persistence are not destined for future underachievement on physically challenging activities. Given the stability of variables, interventions that target fostering self-regulatory efficacy or effortful persistence may be particularly important for getting children on trajectories toward healthy and sustained levels of physical activity.

[Optimal chemical fertilizer application rate accorded with local economic and ecological benefits].

This paper studied the exterior cost of applying chemical fertilizer on the farmland in Dongting Lake area, one of the main foodstuff production regions in China, aimed to search for an optimal chemical fertilizer application rate accorded with local economic and ecological benefits. The exterior cost was estimated by the method of economic and environmental evaluation, while the optimal application rate was calculated based on Exterior Diseconomy Theory and by using production function model, with both ecological and farmers' economic benefits considered. The results showed that in 2002, the exterior cost of inappropriately applying chemical fertilizer was about 1.35 x 10(8) yuan, equivalent to 0.3 yuan x kg(-1) fertilizer N. Under current situation of test area, the optimal application rate of chemical fertilizer should be 208.26 - 210.65 kg x hm(-2), and the corresponding foodstuff supply would be 5528 - 5539 kg x hm(-2). However, the actual fertilizer application rate in 2002 exceeded the optimal one. A suggestion was made to impose tax for the environmental pollution of over-using chemical fertilizer.

[Environmental cost of rice production in Dongting Lake area of Hunan Province].

To evaluate the environmental cost of rice production is of significance for the sustainable development of agriculture and the set-up of green GDP accounting system. In this paper, the environmental cost of rice production in Dongting Lake area, one of the main bread baskets in China, was evaluated from the aspects of pesticide pollution, chemical fertilizer pollution, greenhouse gases emission, plastic film persistence, paddyfield gleyization, and polderization. The results showed that in 1999, the total environmental cost of rice production in this area was 41.91 billion yuan, equivalent to 26.8% of its total agricultural production value, or 28.5% of the gross output of its planting industry. For the sustainable production of rice, the strategies for decrease environmental cost intrinsically were put forward.