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51.
In recent years, heavy metal pollution accidents have occurred in many regions of China, and the public has become increasingly concerned about its health. Based on a U.S. Environmental Protection Agency model and using Monte Carlo simulation techniques, this article presents a procedure for health risk assessment of heavy metal pollution. A case study was conducted in the Qixia lead and zinc mining area. Based on the magnitude of heavy metal contamination in the mine factory, vicinal Qixia scenic site and village, the potential health risk calculated for a lifetime of exposure (through ingestion and dermal contact) was determined as the cumulative carcinogenic and non-carcinogenic risk for workers, tourists, and local residents (including children and adults), respectively. The risk assessment indicated that the carcinogenic risk is not significant. However, Pb poses a significant cumulative non-carcinogenic risk, which tends to be serious for workers. Additionally, local children are more vulnerable than adults to the risks associated with heavy metal contamination. Accordingly, risk alleviation and preventive measures should be taken, especially for children and workers.  相似文献   
52.
生态风险预警等级评估和演化趋势模拟,可为生态风险管理提供可靠的辅助决策。以重庆市为研究对象,基于驱动力-压力-状态-影响-响应模型,构建重庆市生态风险预警指标体系,采用正态云模型和集对分析法,定量分析重庆市生态风险时空分异特征和演化趋势。研究结果表明:(1)2013-2019年,重庆市生态风险值呈"上升-下降"的波动趋势,综合生态风险隶属于重警等级,生态风险综合值从0.295下降到0.278,生态环境逐年好转;(2)重庆市生态风险有下降、不变、先上升后降低、先降低后上升以及一直升高5种演化趋势,分别占比39%、16%、5%、21%、24%;(3)重庆市生态风险转移分为两个方向,2013-2016年生态风险空间分异性增大,中警、轻警和无警风险等级不断向东北、东南和西部四周分散转移;2016-2019年生态风险分布格局变化较小,重警风险区在东部聚集;(4)演化趋势模拟结果表明,未来重庆市生态风险降低的区县有13个,占比34%,生态环境有向好发展的趋势;生态风险上升的区县有25个,占比66%,生态环境会有所恶化,但是恶化程度较低。将生态风险等级划分与预警演化趋势相结合,能为城市生态风险管理提供科学依据。  相似文献   
53.
《Endocrine practice》2021,27(11):1156-1164
ObjectiveTo provide a review of the impact of high deductible health plans (HDHPs) on the utilizations of services required for optimal management of diabetes and subsequent health outcomes.MethodsSystematic literature review of studies published between January 1, 2000, and May 7, 2021, was conducted that examined the impact of HDHP on diabetes monitoring (eg, recommended laboratory and surveillance testing), routine care (eg, ambulatory appointments), medication management (eg, medication initiation, adherence), and acute health care utilization (eg, emergency department visits, hospitalizations, incident complications).ResultsOf the 303 reviewed articles, 8 were relevant. These studies demonstrated that HDHPs lower spending at the expense of reduced high-value diabetes monitoring, routine care, and medication adherence, potentially contributing to the observed increases in acute health care utilization. Additionally, patient out-of-pocket costs for recommended screenings doubled, and total health care expenditures increased by 49.4% for HDHP enrollees compared with enrollees in traditional health plans. Reductions in disease monitoring and routine care and increases in acute health care utilization were greatest in lower-income patients. None of the studies examined the impact of HDHPs on access to diabetes self-management education, technology use, or glycemic control.ConclusionAlthough HDHPs reduce some health care utilization and costs, they appear to do so at the expense of limiting high-value care and medication adherence. Policymakers, providers, and payers should be more cognizant of the potential for negative consequences of HDHPs on patients’ health.  相似文献   
54.
The human health risk of soils contaminated with As, Pb, Cu, and Zn was evaluated based on pseudo-total concentrations of metal(loid)s, the physiologically based extraction test (PBET), and diffusive gradients in thin films (DGT). Non-carcinogenic (NCR) and carcinogenic (CR) risks exceeded the U.S. Environmental Protection Agency criteria under both the residential and non-residential scenarios. Human bioavailable concentrations (PBET) were much lower than pseudo-total concentrations. The Hazardous Index of NCR (HI (NCR)) for the PBET in the studied soils was 67% and 94% less than that for pseudo-total concentration, respectively, under the non-residential and residential scenarios. Similarly, CR for the PBET was also 65% and 93% less for the two soils. The concentration of metal(loid)s accumulated in the DGT resin was highly correlated with the PBET-extractable concentration (R2 > 0.649). Therefore, for both the CR and HI (NCR), the DGT-calculated risk was linearly related to the PBET-calculated risk for the studied soils under both scenarios. The results suggest that DGT uptake and PBET-extracted concentrations are good surrogates for risk estimation and that both J1 and J2 soils require remediation before their use for residential or non-residential purposes.  相似文献   
55.
56.
To assess the potential health risks associated with selected trace elements due to consumption of bivalves, a screening-level risk assessment was conducted through consideration of internationally accepted dietary guidelines and the calculation of hazard quotients. Seventeen edible bivalve species were collected from a local market in Dalian City, China. The ranges obtained for the trace elements analyzed in mg/kg dry weight were as follows: Cu (1.8–133), Zn (56–693), Mn (5.7–150), Se (0.2–3.8), Ni (0.56–7.67), Cd (0.04–10.3), Cr (0.48–2.23), Pb (0.01–1.63), Hg (0.07–0.35), and As (0.22–4.00). The estimated daily intake (EDI) of bivalves was 15.0–255.1 times lower than the RfD guidelines for all the trace elements studied. Further, the calculated hazard quotients (HQs) of the trace elements analyzed were well less than 1. Therefore, there were no potential human health risks to Dalian City consumers of marine bivalves.  相似文献   
57.
Although systematic, quantitative assessment of environmental health risks is a staple of regulatory decision-making, complaints regarding its perceived failures and shortcomings are an intrinsic feature of the policy landscape. In this article, we (a) catalog the classic criticisms of conventional health risk assessment, (b) create a typology that orders the critiques according to their focus on either input errors or output biases, and (c) identify selected allegations that fall within each category. We also note that the risk assessment–risk management paradigm has evolved over the past several decades, partially in accordance with the general direction and spirit of these classic critiques. The debate continues today along familiar lines invoking the traditional critiques and rebuttals outlined here.  相似文献   
58.
Shoal position can have a strong influence on individual fitness. Individuals in front positions of shoals were observed to have higher feeding rates than individuals elsewhere. Manipulation of nutritional state showed that hungry individuals had a stronger preference for front positions and that the duration of food-deprivation was positively correlated with the degree of the position preference. On the other hand, front positions (like other peripheral positions) probably incur costs in terms of increased predation risks. Experiments with Schreckstoff showed that frightened individuals seek the central part of the shoal. This suggests that individuals rotate their shoal positions according to the tradeoff between energy intake and predation risk.  相似文献   
59.
Daniel Wikler 《Bioethics》2020,34(9):937-940
Scientists seeking to conduct research with human subjects must first submit their proposals to research ethics committees (Institutional Review Boards [IRBs], in the United States). Some of these studies pose risks to “bystanders,” i.e., people who may be affected by the research but who are not enrolled as study subjects. Should IRBs expand their scope to include oversight over possible harms to bystanders as well as research subjects? This paper presents arguments against this step. Prior review of research with human subjects, despite its evident burden on the research enterprise, is a necessary caution, because the tension between the objectives of humane treatment of research subjects and sound scientific design and procedure has in the past led to serious abuses. This rationale is inapplicable in the case of bystanders. Moreover, in view of the many and varied effects of both research practices and scientific advances on the broader public over time, those who may be considered to be “bystanders” may potentially expand without limit; requiring IRBs to anticipate these distant and long-term effects as part of prior ethical review could greatly increase its burden and its deterrent effect on research. While conducting research without concern for serious potential harm to bystanders may be irresponsible and unethical, expanding the scope of prior review by IRBs to include risks to bystanders is not required by the principles governing human subjects research, and the costs and burdens of this expansion may outweigh any expected gains.  相似文献   
60.
Objective: Electromagnetic fields can affect intracellular Ca2+ levels. The aim of this study was to determine the changes intracellular Ca2+ concentration in cardiac ventricle cells of rats exposed to 0.25 mT (2.5 Gauss) magnetic field.

Methods: Forty-five male rats were introduced to this study. The rats were divided into three groups: control, sham, and experiment. The experimental group was exposed to 0.25 mT extremely low frequency (ELF) magnetic field for 14 days, 3 h/day. The sham group was treated like the experimental group, except for elf-magnetic field exposure. The control group was not subjected to anything and differed from the experimental group and sham group. In the end of experiment, rats were sacrificed, cardiac tissue was removed, and these were fixed in 10% neutral formalin. Then, ventricular cells were stained by Alizarin red staining method.

Results: In the light microscopic examinations of control groups, in myofibril structures between groups, changes were not observed. In myofibril regions of the experimental group compared to other groups, increased heterogen Ca2+ accumulations were found.

Conclusion: ELF magnetic fields are used in daily life. The results of this study show that intracellular Ca2+ accumulation in cardiac ventricles can increase in rats exposed to ELF magnetic field.  相似文献   
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