Mixed effect model

  • 文章类型: Journal Article
    背景:目前尚不清楚是什么原因导致阵发性心房颤动(AF)患者的症状。
    目的:本研究旨在将皮肤交感神经活动(SKNA)的大小与房颤患者的症状相关联。
    方法:我们前瞻性招募有症状阵发性房颤患者进行动态心电图和SKNA记录。出现症状时的心律分为AF或正常窦性心律(NSR)。使用混合效应模型比较有症状和无症状AF和NSR发作之间的最大和平均SKNA(aSKNA)和心率(HR),以解释患者内部的相关性。
    结果:在31名患者中,16人(52%)至少有一次房颤发作,和24(77%)认可的症状在监测期间。与无症状房颤发作相比,有症状的AF发作具有较高的最大aSKNA(1.260[IQR1.114-1.723]μVvs.1.108[IQR0.974-1.312]μV,p<0.001)和更高的最大HR(152±24bpmvs.132±19bpm,p<0.001)。症状性NSR发作与较高的最大aSKNA相关(1.612[IQR1.287-2.027]μVvs.1.332[IQR1.033-1.668]μV,p=0.001)和更高的最大HR(152±24bpmvs.105±16bpm,p<0.001)比无症状NSR发作。在症状发作中,66例(73%)发生在NSR期间,24例(27%)发生在AF期间。所有P值都是从混合效应模型获得的。
    结论:阵发性房颤患者的症状性发作与NSR相关的频率高于房颤。与无症状发作相比,有症状的AF和NSR发作与更高的aSKNA相关。阵发性房颤患者,与心律相比,症状与SKNA的相关性更好。
    BACKGROUND: The causes of symptoms in patients with paroxysmal atrial fibrillation (AF) remains unclear.
    OBJECTIVE: The purpose of this study was to correlate the magnitudes of skin sympathetic nerve activity (SKNA) with symptoms in patients with AF.
    METHODS: We prospectively enrolled patients with symptomatic paroxysmal AF for ambulatory electrocardiography and SKNA recording. Heart rhythms at the time of symptoms were categorized as AF or normal sinus rhythm (NSR). Maximal and average skin sympathetic nerve activity (aSKNA) and heart rate (HR) were compared between symptomatic and asymptomatic AF and NSR episodes using mixed effects models to account for within-patient correlations.
    RESULTS: Among the 31 enrolled patients, 16 (52%) had at least 1 episode of AF, and 24 (77%) endorsed symptoms during the monitoring period. Compared with asymptomatic AF episodes, symptomatic AF episodes had higher maximal aSKNA (1.260 [interquartile range (IQR) 1.114-1.723] μV vs 1.108 [IQR 0.974-1.312] μV; P <0.001) and higher maximal HR (152 ± 24 bpm vs 132 ± 19 bpm; P <.001). Symptomatic NSR episodes were associated with higher maximal aSKNA (1.612 [IQR 1.287-2.027] μV vs 1.332 [IQR 1.033-1.668] μV; P = .001) and higher maximal HR (152 ± 24 bpm vs 105 ± 16 bpm; P <.001) than asymptomatic NSR episodes. Of the symptomatic episodes, 66 (73%) occurred during NSR and 24 (27%) during AF. All P values were obtained from mixed effects models.
    CONCLUSIONS: Symptomatic episodes in patients with paroxysmal AF were more frequently associated with NSR than AF. Symptomatic AF and NSR episodes were associated with higher aSKNA than asymptomatic episodes. In patients with paroxysmal AF, symptoms correlate better with SKNA than heart rhythm.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    尽管低出生体重(LBW)的患病率随着时间的推移有所下降,它作为孟加拉国公共卫生问题的持续重要性仍然显而易见。低出生体重被认为是导致婴儿死亡率的一个因素,长期的健康并发症,以及对非传染性疾病的脆弱性。本研究利用2012-2013年和2019年进行的多指标类集调查(MICS)的全国代表性数据来探讨与出生体重相关的因素。出生体重数据建模考虑了因素之间的相互作用,数据中的聚类,和空间相关性。生成区级地图以识别LBW的高风险区域。平均出生体重略有增加,从2012-2013年的2.93公斤上升到2019年的2.96公斤。这项研究采用了回归树,一种流行的机器学习算法,辨别出生体重潜在决定因素之间的基本相互作用。各种模型的发现,包括固定效应,混合效应,和空间依赖模型,强调产妇年龄等因素的重要性,户主的教育,产前保健,很少有数据驱动的相互作用影响出生体重。特定地区的地图显示,西南地区和选定的北部地区的平均出生体重较低,在两个调查期间坚持。考虑层次结构和空间自相关,提高了模型性能,特别是在拟合最近一轮调查数据时。该研究旨在通过利用机器学习技术和回归模型来识别需要高度关注的弱势儿童群体,从而为地区一级的政策制定和有针对性的干预措施提供信息。
    Despite a decrease in the prevalence of low birth weight (LBW) over time, its ongoing significance as a public health concern in Bangladesh remains evident. Low birth weight is believed to be a contributing factor to infant mortality, prolonged health complications, and vulnerability to non-communicable diseases. This study utilizes nationally representative data from the Multiple Indicator Cluster Surveys (MICS) conducted in 2012-2013 and 2019 to explore factors associated with birth weight. Modeling birth weight data considers interactions among factors, clustering in data, and spatial correlation. District-level maps are generated to identify high-risk areas for LBW. The average birth weight has shown a modest increase, rising from 2.93 kg in 2012-2013 to 2.96 kg in 2019. The study employs a regression tree, a popular machine learning algorithm, to discern essential interactions among potential determinants of birth weight. Findings from various models, including fixed effect, mixed effect, and spatial dependence models, highlight the significance of factors such as maternal age, household head\'s education, antenatal care, and few data-driven interactions influencing birth weight. District-specific maps reveal lower average birth weights in the southwestern region and selected northern districts, persisting across the two survey periods. Accounting for hierarchical structure and spatial autocorrelation improves model performance, particularly when fitting the most recent round of survey data. The study aims to inform policy formulation and targeted interventions at the district level by utilizing a machine learning technique and regression models to identify vulnerable groups of children requiring heightened attention.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    背景:我们旨在评估短期每日温度变异性(DTV)对血压正常参与者的血压(BP)的影响,高血压前期,和高血压,分别,探索不同气候带和季节的影响。
    方法:涵盖亚热带的代表性人口样本(n=397,173),温带大陆,温带季风区是从中国高血压调查中获得的。DTV计算为暴露日期间每日最低和最高温度的标准偏差。线性混合效应回归模型用于估计DTV暴露与血压之间的关系。高血压前期,和高血压,分别,并按气候区和季节进行了进一步的分层分析。
    结果:调整混杂因素后,在亚热带地区的高血压参与者中,暴露0~6日时DTV(2.28°C)每四分位数间距(IQR)的增加与收缩压(SBP)(SBP)和脉压(PP)0.41mmHg(95%CI:0.09,0.72)的增加相关.同样,在温带大陆地区的高血压前期参与者中,DTV暴露与SBP增加0.31mmHg(95%CI:0.06,0.55)和PP增加0.59mmHg(95%CI:0.24,0.94)相关。此外,在温暖的季节,在高血压前期和高血压人群中,DTV与SBP呈正相关,在所有三个人群中都有PP。
    结论:在亚热带地区和温带大陆地区,短期DTV暴露与高血压和高血压前期参与者的SBP和PP升高相关。此外,在温暖季节有高血压前期和高血压的参与者中观察到DTV与SBP和PP呈正相关.应实施全面的健康教育和有效的干预策略,以减轻温度变化对BP的影响,特别是在高血压前期和高血压人群中。
    BACKGROUND: We aimed to evaluate the impacts of short-term daily temperature variability (DTV) on blood pressure (BP) among participants with normotension, prehypertension, and hypertension, respectively, and explore the effects in different climate zones and seasons.
    METHODS: A representative population sample (n = 397,173) covering the subtropical, temperate continental, and temperate monsoon zones was obtained from the China Hypertension Survey. DTV was calculated as the standard deviation of daily minimum and maximum temperatures during the exposure days. The linear mixed effect regression model was used to estimate the associations between DTV exposure and BP among normotension, prehypertension, and hypertension, respectively, and further stratified analysis was performed by climate zones and seasons.
    RESULTS: After adjustment for confounders, per interquartile range (IQR) increase in DTV (2.28 °C) at 0-6 days of exposure was associated with an increase of 0.41 mmHg (95 % confidence interval [CI]: 0.07, 0.75) in systolic BP (SBP) and 0.41 mmHg (95 % CI: 0.09, 0.72) in pulse pressure (PP) among hypertensive participants in the subtropical zone. Similarly, DTV exposure was associated with an increase of 0.31 mmHg (95 % CI: 0.06, 0.55) in SBP and 0.59 mmHg (95 % CI: 0.24, 0.94) in PP among prehypertensive participants in the temperate continental zone. Additionally, during the warm season, DTV was positively associated with SBP among populations with prehypertension and hypertension, and with PP among all three populations.
    CONCLUSIONS: Short-term DTV exposure was associated with an increase in SBP and PP among hypertensive and prehypertensive participants in the subtropical zone and the temperate continental zone. In addition, positive associations of DTV with SBP and PP were observed among participants with prehypertension and hypertension in the warm season. Comprehensive health education and effective intervention strategies should be implemented to mitigate the effects of temperature variations on BP, particularly among prehypertensive and hypertensive populations.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    该试验旨在评估绿豆品种的产量表现和盈利能力,并调查研究区农户的创新倾向。该实验是在主要生长期在北Shewa地区的潜在环境中进行的两年。作为实验性治疗,四个绿豆品种的Rasa,NLV-1,Arkebe,在四个环境中使用和评估了当地品种(每个环境两个农民田地)。实验地块以简单的随机块设计排列。联合方差分析的结果表明,基因型之间的籽粒产量差异非常显着(p<0.01),而环境和环境相互作用的基因型差异不大。从改良品种Rasa获得的最高平均谷物产量为1430.6kgha-1,首先由农民选择,然后是品种NVL-1。结果还证实了实际价值等级和农民对谷物和生物量产量的偏好等级之间存在很强的统计学意义的关联(R=.80,p<.001)。此外,品种Rasa提供最高(686.6%)的边际投资回报率。因此,通过考虑谷物产量表现的结果,农民的选择,以及部分预算分析的结果,品种Rasa被推荐用于研究区域。
    The experiment is designed to evaluate the yield performance and profitability of mung bean varieties and to survey the innovation inclination of the farmers in the study area. The experiment was carried out in the potential environments of the North Shewa zone for two years during the main growing period. As experimental treatments, four mung bean cultivars of Rasa, NLV-1, Arkebe, and local varieties were used and evaluated across the four environments (two farmers\' fields per each environment). The experimental plots were arranged in a simple random block design. The result of the combined analysis of variance revealed that there was highly significant variation (p < 0.01) of grain yield among the genotypes while the environments and genotype by environment interaction are found insignificant. The highest mean grain yield of 1430.6 kg ha-1 was obtained from the improved variety Rasa, which was selected first by the farmers followed by the variety NVL-1. The results also confirmed the existence of a strong and statistically significant association between the actual values rank and the farmers\' preference rank for both grain and biomass yields (R = .80, p < .001). Also, the variety Rasa provides the highest (686.6%) marginal rate of return on investment. Therefore, by considering the results of the grain yield performance, farmers\' selection, and the result of the partial budget analysis the variety Rasa was recommended for the study areas.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    PM2.5污染在越南和世界各地都是一个严重的问题,对人类健康有不良影响,动物和环境。定期大规模监测对于评估空气污染状况非常重要,制定解决方案并评估政策执行的有效性。然而,越南的空气质量监测站有限。在这篇文章中,我们提出了一种方法来估算2012年至2020年越南领土上的每日PM2.5浓度,受到多云条件的强烈影响,在地面PM2.5测量数据组成的数据集上使用名为混合效应模型(MEM)的现代统计模型,综合卫星气溶胶光学深度(AOD),气象和土地利用图。这种方法的结果是第一个长期的,越南的全面覆盖和高质量的PM2.5数据集。与地面PM2.5测量相比,每日平均PM2.5图具有较高的验证结果(在总共13,886个数据样本中,Pearsonr为0.87,R2为0.75,RMSE为11.76μg/m3,MRE为36.57%)。与另一种全球PM2.5产品相比,越南2012年至2020年的月度和年度平均地图具有出色的质量。PM2.5浓度图显示了2012年至2020年越南PM2.5浓度的空间分布和季节变化,并已用于国家范围内的环境和公共卫生的其他研究和应用。由于缺乏监测站和适当的PM2.5建模方法,这在以前是不可能的。
    PM2.5 pollution is a serious problem in Vietnam and around the world, having bad impacts on human health, animals and environment. Regular monitoring at a large scale is important to assess the status of air pollution, develop solutions and evaluate the effectiveness of policy implementation. However, air quality monitoring stations in Vietnam are limited. In this article, we propose an approach to estimate daily PM2.5 concentration from 2012 to 2020 over the Vietnamese territory, which is strongly affected by cloudy conditions, using a modern statistical model named Mixed Effect Model (MEM) on a dataset consisting of ground PM2.5 measurements, integrated satellite Aerosol Optical Depth (AOD), meteorological and land use maps. The result of this approach is the first long-term, full coverage and high quality PM2.5 dataset of Vietnam. The daily mean PM2.5 maps have high validation results in comparison with ground PM2.5 measurement (Pearson r of 0.87, R2 of 0.75, RMSE of 11.76 μg/m3, and MRE of 36.57 % on a total of 13,886 data samples). The aggregated monthly and annual average maps from 2012 to 2020 in Vietnam have outstanding quality when compared with another global PM2.5 product. The PM2.5 concentration maps has shown spatial distribution and seasonal variations of PM2.5 concentration in Vietnam in a long period from 2012 to 2020 and has been used in other studies and applications in the environment and public health at the national scale, which has not been possible before because of the lack of monitoring stations and an appropriate PM2.5 modeling approach.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    尽管发表了大量与COVID-19相关的研究论文,目前尚不清楚哪些因素与观察到的全球传播变化相关,以及它们的相对重要性水平如何.本研究应用了严格的统计框架,以提供对因素影响的可靠估计,以从全球和综合的角度看待这一问题。我们开发了一个混合效应模型,探索驱动COVID-19传播的潜在因素的相对重要性,同时结合了传播的时空异质性。我们使用六大洲87个国家的综合数据集进行模型规范和拟合。最佳模型在分析的数据中占70.4%的方差:10个固定效应因子解释了20.5%的方差,随机时空效应占方差的50%。固定效应因素分为气候,人口统计学和疾病对照组。三组在全球传播中的解释方差为0.6%,1.1%,分别为4.4%。随机效应所占的方差比例很高,这表明各国之间的时间传播轨迹和人口流动性影响存在显着差异。特别是,在解释COVID-19大流行早期观察到的传播的全球变化方面,特定国家的流动-传播关系被证明是最重要的因素.
    Despite a substantial number of COVID-19 related research papers published, it remains unclear as to which factors are associated with the observed variation in global transmission and what are their relative levels of importance. This study applies a rigorous statistical framework to provide robust estimations of the factor effects for a global and integrated perspective on this issue. We developed a mixed effect model exploring the relative importance of potential factors driving COVID-19 transmission while incorporating spatial and temporal heterogeneity of spread. We use an integrated data set for 87 countries across six continents for model specification and fitting. The best model accounts for 70.4% of the variance in the data analyzed: 10 fixed effect factors explain 20.5% of the variance, random temporal and spatial effects account for 50% of the variance. The fixed effect factors are classified into climatic, demographic and disease control groups. The explained variance in global transmission by the three groups are 0.6%, 1.1%, and 4.4% respectively. The high proportion of variance accounted for by random effects indicated striking differences in temporal transmission trajectories and effects of population mobility among the countries. In particular, the country-specific mobility-transmission relationship turns out to be the most important factor in explaining the observed global variation of transmission in the early phase of COVID-19 pandemic.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    建立混合效应数学模型,分析妊娠期糖尿病(GDM)新生儿低血糖的影响因素。本研究共纳入229例GDM患者。通过非正态分布的对数变换对数据进行分析。此外,利用数学模型分析GDM妇女新生儿低血糖的影响因素。结果表明,血糖分布水平随时间的延长有增加的趋势,提示加强GDM产妇对新生儿的血糖干预是必要的,为及时发现GDM新生儿的低血糖提供了数据。此外,成功建立了GDM新生儿血糖水平混合数学模型。从这个模型来看,我们基于混合因素计算GDM新生儿血糖正常置信区间.结果表明,GDM新生儿血糖水平的最小值未超过2.2mmol/L的风险水平。我们得出结论,成功建立了数学混合效应模型,从中发现GDM产妇新生儿血糖水平的变化规律。在中国,妊娠期糖尿病(GDM)的发病率已经增加。然而,临床数据难以收集,用于统计的数据不够,这使得对GDM新生儿低血糖的认识变得困难。这项研究的结果补充了什么?在这项研究中,我们成功建立了GDM妇女新生儿低血糖的数学混合效应模型,探讨GDM产妇新生儿低血糖的影响因素,通过数学模型发现GDM产妇新生儿血糖水平的变化规律。这些发现对临床实践和/或进一步研究有什么意义?我们的研究有助于更好地了解和改善GDM孕妇及其新生儿的健康问题。
    A mathematical mixed effect model was established to analyse the factors of neonatal hypoglycaemia of gestational diabetes mellitus (GDM). 229 cases of GDM patients were enrolled in this study. The data were analysed by logarithmic transformation of non-normal distribution. Furthermore, the mathematical model was used to analyse influencing factors of hypoglycaemia of neonatal from women with GDM. The results showed that the blood glucose distribution level had a trend of increasing with time, which indicates that it is necessary to strengthen blood glucose intervention of newborns from GDM maternal and provides a data for the timely detection of hypoglycaemia in GDM newborns. Furthermore, we successfully established the GDM newborn blood glucose level mixed mathematical model. From this model, we calculated the GDM newborn blood glucose normal confidence interval based on mixed factors. The results indicate that the minimum value of blood glucose level in GDM newborns did not exceed the risk level 2.2 mmol/L. We concluded that the mathematical mixed effect model is successfully established, from which the change discipline of blood glucose level of newborn from GDM parturient are found. Impact statementWhat is already known on this subject? The morbidity of gestational diabetes mellitus (GDM) in China has been increased. However, the clinical data is difficult to be collected and the data that is used for statistics is not enough, which makes it difficult to understand the neonatal hypoglycaemia of GDM more clearly.What do the results of this study add? In this study, we successfully established a mathematical mixed effect model of neonatal hypoglycaemia of women with GDM, which can investigate the influence factor of hypoglycaemia of newborn from women with GDM to find the discipline of blood glucose level of newborn from GDM parturient via mathematical model.What are the implications of these findings for clinical practice and/or further research? Our research helps to better understand and improve the health problem of pregnant women with GDM and their newborn babies.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    由于2019年冠状病毒病(COVID-19)的不断变化,重要的是要了解疾病状况和社会经济之间的关系,人口统计学,和各地区的健康指标。
    研究传染病与社会经济变量之间的关系的研究尚未得到很好的确立。
    美国总共3042个县被纳入研究中作为观察单位。研究中采用的两个结果变量是控制每个县的疾病传播和感染患病率。
    数据提交分位数回归,分层回归,和随机森林分析,以了解人口统计学对健康结果的影响程度,社会经济学,和健康指标。
    疾病传播控制较好的县的感染率往往较低,反之亦然。当测量不同的结果变量时,具有5%统计学意义的COVID-19的常见危险因素包括就业率,女性劳动力比例,年轻人口比例,和居民的平均健康风险因素,虽然保护因素包括土地面积,住房价值,上班的时间,女性人口比例,以及认同自己是混血儿的居民比例。
    这些发现的含义是,保持社交距离和个人卫生习惯的能力对于阻止疾病传播和降低发病率至关重要。尤其是在疾病形成的早期。有关当局应确定预防因素,并在未来及早采取行动与传染病作斗争。
    Due to the evolving variants of coronavirus disease 2019 (COVID-19), it is important to understand the relationship between the disease condition and socioeconomic, demographic, and health indicators across regions.
    Studies examining the relationships between infectious disease and socioeconomic variables are not yet well established.
    A total of 3042 counties in the United States are included as the observation unit in the study. Two outcome variables employed in the study are the control of disease spread and infection prevalence rates in each county.
    Data are submitted to quantile regression, hierarchical regression, and random forest analyses to understand the extent to which health outcomes are affected by demographics, socioeconomics, and health indicators.
    Counties with better control of the disease spread tend to have lower infection rates, and vice versa. When measuring different outcome variables, the common risk factors for COVID-19 with a 5% level of statistical significance include employment ratio, female labor ratio, young population ratio, and residents\' average health risk factors, while protective factors include land size, housing value, travel time to work, female population ratio, and ratio of residents who identify themselves as mixed race.
    The implications of the findings are that the ability to maintain social distancing and personal hygiene habits are crucial in deterring disease transmission and lowering incidence rates, especially in the early stage of disease formation. Relevant authorities should identify preventive factors and take early actions to fight infectious diseases in the future.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    (1)背景:本研究的目的是评估牙齿表面消毒治疗的预防效果,除了氟化物的应用,在固定正畸治疗期间。(2)方法:对在正畸科就诊的高龋齿风险患者进行了一项开放标签的随机对照试验,以评估龋齿预防程序。Tsurumi大学牙科医院正畸治疗。随访期为6个月。通过定量光诱导荧光(QLF)评估白斑病变(WSL)。通过细菌培养监测和评估致龋细菌。此外,通过下一代序列(NGS)评估口腔微生物组.(3)结果:通过混合效应建模,牙齿表面消毒处理显着减少了致龋细菌和QLF获得的所有参数。(4)结论:牙面消毒处理,除了PMTC和氟化物应用外,在正畸治疗期间对预防龋齿和保持健康的微生物组有效。
    (1) Background: The aim of this study was to assess the preventive effect of tooth surface disinfection treatment, in addition to fluoride application, during fixed orthodontic treatment. (2) Methods: An open label randomized control trial for the evaluation of the dental caries preventive procedure was performed for the patients with high caries risk who had been visited at Department of Orthodontics, Tsurumi University Dental Hospital for orthodontics treatment. The follow-up period was six months. White spot lesions (WSLs) were evaluated by quantitative light-induced fluorescence (QLF). Cariogenic bacteria were monitored and evaluated by bacterial culture. In addition, the oral microbiome was evaluated by a next-generation sequence (NGS). (3) Results: By the mixed effect modeling, tooth surface disinfection treatment significantly reduced cariogenic bacteria and all parameters obtained by QLF. (4) Conclusions: Tooth surface disinfection treatment, in addition to PMTC and fluoride application, were effective for dental caries prevention and keeping a healthy microbiome during orthodontic treatment.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    据报道,建筑工人体内有高浓度的可吸入石英,铸造厂,还有采石场.目前,对普遍但可能较低暴露职业的暴露浓度的研究较少。我们的目标是量化目前主要职业中可吸入粉尘和石英的暴露浓度,并确定这些职业中可吸入石英暴露的决定因素。
    2018年,对丹麦11个职业的工人的可吸入粉尘的一百八十九份全班个人样本进行了采样。重量法测定可吸入粉尘,并用红外光谱法分析石英含量。可吸入石英暴露的决定因素,即使用电动工具,室外或室内位置,和可吸入粉尘中石英的百分比,在线性混合效应模型中进行了分析。
    可吸入粉尘和石英的总体几何平均值(几何标准偏差)为216µgm-3(4.42)和16µgm-3(4.07),分别。在切石机和雕刻机中观察到最高的石英浓度[93µgm-3(3.47)],以及金属熔炉和脚轮[61µgm-3(1.71)]。使用电动工具使石英的暴露浓度增加了3.5倍。职业解释了27%,职业内的公司28%,和工人之间的差异公司内的职业14%的变化的石英浓度。30%是由于暴露浓度的日常变化。总的来说,石英浓度变化的19%可以用工具类型来解释,室内/室外位置,和可吸入粉尘中石英的百分比。
    当前暴露浓度通常较低,但是这项研究中的一些职业对可吸入石英的平均暴露浓度高于ACGIH阈值极限值25µgm-3。仍然需要采取预防措施,以降低这些工人患石英相关疾病的额外风险。在预防策略方面,电动工具的使用和所用材料的石英含量被确定为暴露的主要决定因素。当关注这些主要决定因素时,降低曝光将是最有效的,例如,用水控制工具粉尘,除尘,和使用低石英含量的材料。
    High concentrations of respirable quartz have been reported from workers in construction, foundries, and quarries. Current exposure concentrations in prevalent but presumably lower exposed occupations have been less examined. We aimed to quantify current exposure concentrations of respirable dust and quartz across prevalent occupations and to identify determinants of respirable quartz exposure across these occupations.
    One hundred and eighty-nine full-shift personal samples of respirable dust of workers within 11 occupations in Denmark were sampled during 2018. Respirable dust was determined gravimetrically and analysed for quartz content with infrared spectrometry. Determinants for respirable quartz exposure, i.e. use of power tools, outdoor or indoor location, and percentage of quartz in respirable dust, were analysed in linear mixed effect models.
    The overall geometric means (geometric standard deviations) for respirable dust and quartz were 216 µg m-3 (4.42) and 16 µg m-3 (4.07), respectively. The highest quartz concentrations were observed among stone cutters and carvers [93 µg m-3 (3.47)], and metal melters and casters [61 µg m-3 (1.71)]. Use of power tools increased exposure concentrations of quartz by a factor of 3.5. Occupations explained 27%, companies within occupations 28%, and differences between workers within companies within occupations 14% of the variability in quartz concentrations. Thirty percent was due to day-to-day variability in exposure concentrations. In total, 19% of the variation in quartz concentration could be explained by type of tool, indoor/outdoor location, and percentage of quartz in respirable dust.
    Current exposure concentrations are generally low, but some occupations in this study had average exposure concentrations to respirable quartz above the ACGIH threshold limit value of 25 µg m-3. Preventive measures to lower excess risk of quartz-related diseases among these workers are still needed. In terms of preventive strategies, use of power tools and quartz content of used materials were identified as main determinants of exposure. Lowering of exposures will be most efficient when focussed on these major determinants, e.g. tool dust control with water, dust extraction, and use of low quartz content materials.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

公众号