Health Risks Associated with Heavy Metals in Fine Particulate Matter: A Case Study in Delhi City, India

The concentrations of twenty five heavy metals adsorbed to fine fraction of particulate matter, PM2.5 (d ≤ 2.5 μm) have been experimentally analysed at a sampling site located at the kerbside along a National Highway in Delhi city, India. The sampling has been carried out for 12-hour using Ecotech Intruments, APM550. The PM2.5 has been collected on PTFE filter papers for the winter season. Later, the filter papers have been analysed for various heavy metal concentrations using ED-XRF. It has been observed that the metals concentrations are in this trend: Si > K > S > Ca = Fe > Zn = Pb > Br. it is observed that Si has high co-relation with Ca, Fe and K, which may be due to crustal origin of all three elements;while S, Br and Pb may be from vehicular exhaust emissions and/or abrasions due to brake and tyre wear. The potential health risks associated with different carcinogenic heavy metals have also been calculated. One of the health risk indicators, the excess cancer risk (ECR), is found to be in the order as As > Cd > Pb > Cr > Ni.

Cancer Risk Due to the Natural Radioactivity in Cigarette Tobacco

Thirty-one samples of cigarettes have been collected from local markets of different types of origins. The samples were selected according to a survey distributed to smokers by paper and digital survey to see the most heavily traded among smokers and in addition to a number of questions to see how the awareness and the culture of smokers in diseases caused by smoking and considered this study the first survey in Iraq. The aim of this research is to assess the number of cancer cases due to cigarette smoking. Through the use of High-Purity Germanium system (HPGe) (efficiency 40%) we determinated the radionuclides in cigarette tobacco. The average values were (14.86 ± 3.76, 10.84 ± 3.13, 1050.64 ± 47.57) Bq/kg for Ra-226, Th-232 and K-40, respectively, and the excess lifetime of cancer risk values ranged from 0.54 to 130 at average of 76 per million person per year. Raeq values varied from 18.50 to 87.21.4 Bq/kg with an average value of 39.51 Bq/kg for tobacco samples. The annual effective dose (HE) varies from 16.38 μSv/y to 44.69 μSv/y with an average value of 24.97 μsv/y. The Annual Gonadal Dose Equivalent (AGDE) varies from 0.3 to 0.64 (mSv/y) with an average value of 0.42 for all tobacco samples under investigation.

Investigation of the Radiological Risk of Farmlands and the Transfer Factor from Soil to Crops in Jalingo and Wukari L.G.A of Taraba State, Nigeria

The activity concentrations of radionuclides, absorbed dose rate, excess lifetime cancer risk, and soil-to-plant transfer factor have been evaluated in soil and crop samples from Jalingo and Wukari Local Government Area of Taraba State, Nigeria. The activity concentrations were determined with the aid of High Purity Germanium detector. The absorbed dose and excess lifetime cancer risk were evaluated and forecasted for 60 years using the ResRad off-site model. The average activity concentration of 40K, 232Th, and 238U in the soil samples were 633.13, 141.15, and 71.20 Bq·kg-1 respectively, for the Jalingo study area, and while that of the Wukari study area was;199.21, 87.23, and 25.37 Bq·kg-1 respectively. The average soil-to-plant transfer factors for 40K, 232Th, and 238U were 0.51, 0.10, and 0.27 respectively for the Jalingo study area while that of Wukari are 0.40, 0.57, and 0.74 respectively. The mean annual effective dose equivalent for the study area is higher than the world average of 0.07 mS·vy-1. The excess lifetime cancer risk for the study areas has values that are higher than the safety limit. The ResRed model showed that direct radiation from the crops is the major contributor to excess cancer risk among other pathways. The radiological hazard indices reveal health risks to farmers, especially in the Jalingo area.

Health Risk Assessment for Bromate (BrO₃^–) Traces in Ozonated Indian Bottled Water

For this study, bromide and bromate ions in various commercial brands of Indian bottled water samples were estimated using ion chromatography. The measured mean concentration of bromide and bromate ions in water samples was found to be 28.13 μg/L and 11.17 μg/L respectively. The average level of bromate in Indian bottled water was found to be slightly higher (~ 12%) than the acceptable limits (10 μg/L) recommended by USEPA (US Environmental Protection Agency). Though, kinetically, it is predicted that 62.5% (6.25 μg/L) of bromide in bottled water is needed to convert into bromate upon ozonation to exceed the minimum acceptable limits, but the average formation of bromate determined to be only 26.77% of the predicted concentration. Bromate concentration in bottled water showed a strong correlation with bromide suggesting that its formation in water is very much influenced and controlled by bromide content. The objective of the present study was to determine the BrO3–) content of commercially available different brands of bottled drinking water in India and to estimate the health risks to population due to ingestion. Results of estimated excess cancer risk and chemical toxicity risk to Indian population due to ingestion of bottled water were presented and discussed.

Low-dose ionizing radiation exposure and risk of leukemia: results from 1950-1995 Chinese medical X-ray workers’ cohort study and meta-analysis

Background:It has been well-established that acute radiation exposures increase the risk of leukemia.However,it is still unknown whether these leukemia risk estimates could be extrapolated to occupational populations who receive repeated low-dose radiation exposure.The purpose of this study was to estimate quantified associations between low-dose radiation exposures and leukemia.Methods:The Chinese medical X-ray worker study(CMXW)included 27,011 medical X-ray workers employed at major hospitals in 24 provinces in China from 1950 to 1980,and a control population of 25,782 physicians matched by hospital,who were unexposed to X-ray equipment.Poisson regression models were used to esti-mate the excess relative risk(ERR)and excess absolute risk(EAR)for the incidence of leukemia associated with cumulative doses.A meta-analysis of the published literature on low-dose occupational radiation exposure and leukemia risk was also conducted.Results:The incidence rates of leukemia in X-ray workers and the control group were 6.70 and 3.39 per 100,000 person-years,respectively.Among X-ray workers,the average cumulative red bone marrow dose was 0.046 Gy.We found a positive relationship between 2-year lagged cumulative red bone marrow dose and risk of leukemia excluding chronic lymphocytic leukemia(CLL)(ERR=0.66 per 100 mGy,90%CI:0.09,1.53;EAR=0.29 per 104 PY-100 mGy,90%CI:0.07,0.56).The excess risk was largely driven by myeloid leukemia(ERR=1.06 per 100 mGy,90%CI:0.22,2.51).Based on the meta-analysis,the pooled ERR at 100 mGy was 0.19(95%CI:0.08,0.31).Conclusion:This study provides strong evidence of a positive and linear doseresponse relationship between cu-mulative red bone marrow dose and the incidence of non-CLL leukemia.

Cardiovascular Risk Burden in Sub-Saharan Africans with Rheumatoid Arthritis: A Hospital-Based Study in Yaounde, Cameroon

Introduction: Studies on RA (rheumatoid arthritis) and cardiovascular risk in African countries are scarce. Objective: To investigate the relationship between RA and cardiovascular risk in Cameroonian patients. Methodology: In 50 Black RA patients and 51 matched healthy individuals from the general population, we studied cardiovascular risk factors validated by the WHO. Cardiovascular risks estimates were carried out using WHO risk charts for the African region. Epi-info, R and SPPS were used for the statistical analysis. Results: Overall and abdominal adiposity as expressed by increased body mass index and abdominal obesity, were all markedly increased in RA patients compared to non-RA subjects [70% vs. 47%, OR (95% CI) = 2.62 (1.16 - 5.94), p = 0.026;and 54% vs. 33%, OR (95% CI) = 2.34 (1.05 - 5.25), p = 0.045 respectively]. RA patients were more physically inactive than their non-RA counterparts (20% vs. 0, p = 0.001). Whereas RA was associated with a reduced odds of alcoholism [OR (95% CI) = 0.19 (0.06 - 0.62), p = 0.005]. Increased BMI seemed to occur independently of methotrexate (p = 0.76), hydroxychloroquine (p = 0.59), corticosteroids (p = 0.79) treatments, and independently of sex (p = 0.15), age (p = 0.67), and sedentary lifestyle (p = 0.16) in RA patients;but their BMI was weakly correlated with disease duration (r = 0.26;p = 0.074). Meanwhile, male gender was associated with a reduced odds of abdominal obesity [OR (95% CI) = 0.02 (0 - 0.4), p = 0.011]. Cardiovascular risk, comparable by proportions between RA and non-RA subjects, was low in 26 patients (78.8%) and 30 non-RA subjects (83.3%) respectively. Conclusion: Despite the high adiposity burden and a sedentary lifestyle experienced by RA patients compared to their healthy counterparts, RA was not associated with cardiovascular risk as estimated by WHO risk charts.

金融科技能够抑制企业过度负债吗?

本文以2011—2021年中国上市公司为研究样本,采用北京大学数字普惠金融指数度量金融科技发展水平,实证检验金融科技对企业过度负债的影响。研究结果表明,金融科技能够助力银行等金融机构提升事前的信息甄别能力和加强事后的债权人监督功能,继而抑制企业过度负债行为。进一步的研究显示,金融科技对企业过度负债行为的抑制作用在国有企业和产品市场竞争程度低的行业企业中更加显著,并且金融科技能够通过抑制过度负债而降低企业债务违约风险。本文不仅在理论上丰富了金融科技影响效应和企业过度负债缓解机制的文献,而且在实践上为利用金融技术进步推动微观企业优化资本结构,助力实体经济高质量发展提供了依据。

股份回购与公司资金成本:财务风险视角

以2005—2022年沪深A股上市公司股份回购数据为样本,考察回购前后资金成本变化情况,发现股份回购后企业资金成本呈上升趋势,其中,对于财务风险大的公司,回购导致资金成本上升的情况更加明显。进一步研究也表明,财务风险大的公司,在回购宣告后,其长期市场反应也更差。研究从资金成本角度解释了当前中国股份回购长期价值缺失的原因,揭示出股份回购的长期价值效应受企业内部条件的作用。

超额商誉与商业信用成本:基于风险和内控视角

为厘清超额商誉与商业信用成本间的关系,从供应商与企业间融资成本视角出发,以2014—2021年沪深A股公司为样本,基于信号传递理论,分析超额商誉对商业信用成本的影响机制。研究发现:超额商誉正向影响企业商业信用成本;超额商誉通过加剧企业经营风险,进而增加商业信用成本;较高的内部控制质量对超额商誉与商业信用成本间关系起负向调节作用,且随着内部控制质量的提升,超额商誉加剧经营风险的作用会有所减少,相应其对商业信用成本的正向影响也会减弱;在独立董事比例高、高管股权激励水平高和高管薪酬激励水平低的情形下,超额商誉对商业信用成本的正向影响降低,较高的独董比例和高管股权激励能一定程度缓解超额商誉的负面影响。

企业社会责任履行与超额商誉抑制

在坚决打好防范化解金融风险攻坚战的大背景下,企业社会责任履行对于推动资本市场平稳运行和企业高质量发展具有重要战略意义。近年来上市公司超额商誉带来的巨大商誉泡沫已成为隐藏在资本市场中的重要金融风险因素,给我国资本市场稳定和企业健康发展带来一定的负面影响。企业履行社会责任作为一种自我规制的治理策略和长期价值追求,通过提高信息透明度和企业声誉,抑制了企业超额商誉,且股东责任履行对超额商誉的抑制作用最为显著。企业社会责任履行对于超额商誉的抑制作用主要体现在非国有控股、管理层过度自信、审计师来自非四大事务所和被并购方处于业绩承诺期的企业中。此外,企业社会责任履行可以通过抑制超额商誉来降低企业股价崩盘风险。当前应着力优化监管和治理水平,推动上市公司积极履行企业社会责任,充分释放企业提升社会责任履行水平的正向经济效应。

财务宽裕对企业绿色创新的影响机制与实证检验--兼论社会责任与管理决断权的调节作用

企业是绿色创新的重要主体,资金是绿色创新不可或缺的要素。本文以2011—2020年我国沪深A股1395家上市公司为样本,运用固定效应模型和两阶段检验法,实证检验财务宽裕对绿色创新的影响及作用机制。研究发现,财务宽裕显著促进绿色创新。机制检验结果表明,财务宽裕通过促进企业数字化转型和提高风险承担能力助推企业绿色创新。进一步研究发现,企业社会责任和管理决断权在财务宽裕对绿色创新的影响中发挥反向调节作用;财务宽裕对绿色创新的驱动作用仅存在于成熟期,在成长期与衰退期无明显促进作用。本研究为财务宽裕企业合理利用冗余资源、提高绿色创新水平提供了思路与启示。

静脉超声分级系统对多发性创伤患者住院并发急性肾损伤的预测价值

目的探讨静脉负荷超声(VExUS)分级系统对多发性创伤患者住院并发急性肾损伤(AKI)的预测价值。方法选取2020年11月至2023年12月丽水市中心医院收治的162例多发性创伤患者为研究对象,根据其住院期间是否发生AKI,分为AKI组(n=61)和未AKI组(n=101)。收集患者的临床资料和VExUS得分,采用Logistic回归分析探讨AKI的危险因素,绘制受试者工作特征(ROC)曲线分析VExUS评分的预测价值。同时选取2024年1月至2024年3月期间本院另外收治的符合纳入与排除标准的35例多发性创伤并发AKI患者为验证对象,绘制ROC曲线验证VExUS评分预测多发性创伤患者并发AKI的价值。结果多因素Logistic回归分析结果显示,血清肌酐(SCr)、降钙素原(PCT)、胱抑素C(Cys-C)、C反应蛋白(CRP)、VExUS评分是多发性创伤患者并发AKI的危险因素(P<0.05)。ROC曲线分析结果显示,SCr、PCT、Cys-C、CRP、VExUS评分预测多发性创伤患者并发AKI的曲线下面积(AUC)分别为0.636(95%CI 0.516~0.758,P=0.023)、0.742(95%CI 0.633~0.850,P<0.001)、0.628(95%CI 0.521~0.735,P=0.022)、0.705(95%CI 0.601~0.808,P=0.001)、0.793(95%CI 0.715~0.871,P<0.001),其中VExUS评分预测的ROC最高,最佳截断值为2分,敏感度为81.97%,特异度为61.66%。加以验证的ROC曲线结果显示,VExUS评分对多发性创伤患者并发AKI仍具有良好预测价值,AUC为0.740(95%CI 0.648~0.831)。结论VExUS评分对于多发性创伤患者发生AKI具有良好预测价值。

超额商誉与内部人减持

近年来,并购活动引发的商誉泡沫现象引起了实务界和学术界的广泛关注。本文从内部人减持角度,以2007—2021年A股上市公司为研究对象,考察超额商誉对内部人减持的影响及其作用机制。研究发现,超额商誉会加剧内部人减持。进一步,机制检验表明,超额商誉会通过增加分析师乐观偏差和企业经营风险来影响内部人减持。异质性分析发现,在信息透明度越低、机构持股比例越低、内部人短视越严重的企业,超额商誉加剧内部人减持的作用更明显。此外,超额商誉会加剧内部人清仓式减持;且内部人减持后,企业计提商誉减值的概率和金额会显著增加。本文对进一步规范和完善商誉信息披露制度、保护中小投资者利益具有重要的启示意义。

探究妊娠晚期孕妇出现未足月胎膜早破的高危因素及其防护策略

目的探讨妊娠晚期孕妇出现未足月胎膜早破的高危因素,并制订针对性防护策略。方法选取2021年10月—2023年10月浙江省人民医院毕节医院收治的90例妊娠晚期孕妇为研究对象,对所有孕妇进行随访调查,观察随访期间未足月胎膜早破发生情况,并基于发生情况分组,构建Logistic回归模型,分析妊娠晚期孕妇出现未足月胎膜早破的高危因素。结果经调查,90例妊娠晚期孕妇中有14例发生未足月胎盘早破,占比15.56%。未足月胎盘早破发生组羊水过多、瘢痕子宫、胎位异常、阴道炎症占比高于未发生组,组间差异有统计学意义(P<0.05)。Logistic回归结果显示,羊水过多、瘢痕子宫、胎位异常、阴道炎症是妊娠晚期孕妇出现未足月胎膜早破的高危因素(P<0.05)。结论羊水过多、瘢痕子宫、胎位异常、阴道炎症是妊娠晚期孕妇出现未足月胎膜早破的高危因素,院方可根据孕妇体征及存在的风险因素,及早实施针对性干预。

高管超额薪酬对企业投资效率的影响研究--基于企业风险承担的中介作用

高管薪酬会对企业投资效率产生一定影响。以2010-2021年沪深A股上市公司财务数据为样本,构建固定效应模型对样本数据进行多元线性回归分析。研究发现:高管超额薪酬对企业投资效率具有负向影响,企业风险承担在高管超额薪酬对企业投资效率产生影响的过程中发挥部分中介效应,且这一现象在非国有企业中更显著。以上结果表明,如果企业高管的薪酬水平超过其预期薪酬水平,则会使企业风险承担水平上升,导致企业投资效率降低。建议企业合理制定高管薪酬体系,实施有效监管,并将企业风险承担水平控制在适当区间内,以此确保企业不会出现非效率投资现象,推动企业持续健康发展。

中国资本市场中媒体关注与股票投资回报——风险补偿还是注意力驱动?

本文基于2000~2011年中国重要报纸对A股上市公司的新闻报道月度数据,重新审视了媒体关注与上市公司股票投资收益之间的关系。与Fang和Peress（2009）基于美国数据的研究不同,本文利用中国数据获得的实证结果发现高媒体关注的公司在一年内都比低媒体关注的公司都有更高的超额收益率。这表明Fang和Peress（2009）提出的媒体覆盖的＂风险补偿＂理论在中国并不成立。相反,Barber和Odean（2008）的＂注意力驱动＂理论更能够解释在中国股票市场中媒体与股票收益的关系。进一步的实证结果验证了媒体关注度较高的股票比媒体关注度较低的股票更容易引起投资者的持续关注。而投资者持续更高的关注度引致的买入压力将使得股票在一段时间内都能维持相对更高的收益率。

成都市大气PM_(2.5)相关的老年人超额死亡风险评估

目的探讨成都市大气颗粒物(PM_(2.5))污染所致老年人超额死亡风险。方法收集2013—2016年成都市大气颗粒物(PM_(2.5))日平均浓度、死亡个案数据及气象因素,利用广义相加模型,控制时间的长期趋势、气象因素等混杂因素,分析PM_(2.5)浓度对老年人死亡的影响。收集2017年成都市大气颗粒物(PM_(2.5))日平均浓度和死亡个案数据,根据健康损失计算模型,估算2017年成都市PM_(2.5)污染造成的老年人超额死亡人数。结果单污染物模型显示成都市PM_(2.5)浓度每升高10μg/m^3,老年人非意外总死亡风险增加0.36%(95%CI:0.25%～0.48%),呼吸系统疾病死亡风险增加0.51%(95%CI:0.30%～0.72%),循环系统疾病死亡风险增加0.36%(95%CI:0.16%～0.56%)。多污染物模型中,成都市PM_(2.5)浓度每升高10μg/m^3,老年人非意外总死亡风险增加0.33%(95%CI:0.21%～0.45%),呼吸系统疾病死亡风险增加0.48%(95%CI:0.26%～0.69%),循环系统疾病死亡风险增加0.29%(95%CI:0.09%～0.49%)。2017年成都市老年人因PM_(2.5)污染造成的非意外、呼吸系统疾病、循环系统疾病超额死亡数分别为1 252、540、409人,占当年老年人同死因别总死亡数的1.95%、2.72%、1.94%。结论 PM_(2.5)污染增加老年人超额死亡风险。

广义Poisson回归模型及其应用

目的 探讨广义Poisson回归模型在流行病学队列资料分析中的应用与价值。方法 拟合超额相对危险度模型 ,绝对超额危险度模型 ,非标准模型等分析云锡现场队列研究资料。结果 在云锡肺癌现场 ,每一个观察人年每一工作水平月的氡子体暴露 ,会产生 1 0 9× 10 -5个肺癌超额病例。在总的 336例病例中 ,归因于氡子体暴露的有 12 3例。只有当氡子体累积暴露高于 5 88 37WLM时 ,暴露人群患肺癌危险性才高于基线对照。结论 广义Poisson回归模型的拟合可以得到对于危险因素的更深入描述 ,如计算出每一单位危险因素变化时 ,可得超额相对危险度的变化、以及由危险因素所引起超额病例数、超额绝对危险 (EAR)、归因危险比 (AR)

基于食品安全指数法评估重庆市蔬菜中农药残留的风险

对重庆市的蔬菜生产基地、大型批发市场、农贸市场和超市的7大类蔬菜中的13种农药残留进行抽样监测。结果表明,重庆蔬菜农药残留超标率呈先上升后下降的变化趋势,农药残留平均超标率是豆类>甘蓝类>茄果类>白菜类>绿叶菜类>瓜类>根菜类,市场>基地,外地>本地;除了3月份的氧化乐果对蔬菜安全影响的风险超过了可以接受的限度外,其余月份各种农药残留的安全指数都小于1,对蔬菜安全影响的风险和蔬菜安全状态为可以接受;蔬菜中的甲胺磷、乙酰甲胺磷、甲拌磷、氧化乐果和百菌清残留的R(风险系数)>1.5,处于高、中度风险状态,其余农药皆处于低度风险状态。

超额信贷风险分析

政府干预是一把双刃剑，经济起飞时期，它可以弥补市场信息不对称的缺陷，降低信贷活动的成本，甚至是提高信贷配置的效率；但政府干预并不是无条件、无成本的，其作用前提逐步削弱时，政府往往以强制合同的形式实施干预，强制合同收益与风险不平衡的分摊机制通常会加剧金融机构的道德风险与逆向选择，形成比内生信贷风险更高比例的信贷风险--超额信贷风险。