宜昌市大气微塑料的分布、呼吸暴露及溯源

微塑料作为一种新兴环境污染物备受关注,但大气微塑料的来源和健康危害尚不明晰.为探究宜昌市不同功能区微塑料的分布特征和人体呼吸暴露风险,分析不同地区大气微塑料的可能来源,于2019年10～12月,采集和分析宜昌市16个观测点的大气微塑料样品,并利用HYSPLIT模型模拟大气后向轨迹.结果表明,宜昌市大气微塑料有纤维状、碎片状和薄膜状这3种形状;透明、红色、黑色、绿色、黄色和紫色这6种颜色;尺寸最小的为10.42μm,最大的为4 761.42μm;平均沉降通量为(4 400±474)n·(m²·d)^-1;种类有：聚酯纤维(PET)、丙烯腈-丁二烯-苯乙烯共聚合物(ABS)、聚酰胺(PA)、橡胶(Rubber)、聚乙烯(PE)、醋酸纤维素(CA)和聚丙烯腈(PAN)这7种.各功能区沉降通量依次为：城市居民区>农业生产区>垃圾填埋场>化工园区>城镇居民区.人体呼吸暴露风险评估模型表明,城市居民区成人和儿童每天大气微塑料摄入量(EDI)高于城镇居民区.大气后向轨迹模拟表明,宜昌市各区县大气主要受周边地区影响,部分大气微塑料可能来...     

兰州市空气污染对儿童呼吸疾病的影响

探讨兰州市空气污染对不同性别和年龄的儿童呼吸疾病就诊人数的影响以及季节性变化.通过收集2013~2017年兰州市空气污染物PM_2.5、PM₁₀、SO₂、NO₂、CO和O₃8h浓度数据、气象数据及3家三甲医院儿童呼吸疾病门诊资料,采用广义相加模型（GAM）控制星期几效应、气象因素、假期效应等混杂因素,分析空气污染物浓度与儿童呼吸系统疾病日门诊量的关系及滞后效应.研究期间,兰州市3家三甲医院儿童呼吸系统疾病日门诊量平均为387人次,范围1~1413人次.单污染物模型结果显示,PM_2.5、NO₂、SO₂、CO均在累积滞后一天（lag01）时效应量达到最大值,其浓度每增加10μg/m³（CO单位为1mg/m³）,儿童呼吸系统疾病就诊人次的超额危险度（ER）及95%可信区间（95% CI）分别为0.245%（95% CI：0.127%~0.363%）,0.568%（95% CI：0.327%~0.808%）,1.661%（95% CI：1.022%~2.302%）,2.245%（95% CI：1.610%~2.883%）;PM₁₀和O₃8h在各滞后天数均无统计学意义.对不同性别、年龄、季节分析发现,性别分层中PM_2.5对女童的影响略高于男童,NO₂、SO₂和CO的影响男童略高于女童;年龄分层发现PM_2.5、NO₂和CO的影响6~14岁组大于0~5岁组,SO₂的影响0~5岁组大于6~14岁组;季节分层中PM_2.5、NO₂、SO₂和CO对门诊量的影响只在冬季有意义,PM₁₀和O₃8h在各个季节均无意义.双污染物模型结果显示,分别调整其他5种污染物后,PM₁₀和O₃8h对儿童呼吸系统疾病门诊量的增加均无统计学意义;调整PM₁₀和O₃8h后,其他污染物呼吸系统疾病门诊量的增加均有统计学意义.兰州空气污染物（PM_2.5、NO₂、SO₂、CO）与呼吸系统疾病门诊量密切相关,并且SO₂和CO浓度增加更易增加儿童呼吸系统疾病的发病风险.性别、年龄和季节对空气污染物和呼吸系统疾病门诊就诊人次的关系有影响.     

香烟气相物质引发的脂质过氧化与粒细胞呼吸爆发关系的ESR研究

香烟气相物质和空气都能使卵磷脂脂质体发生脂质过氧化.用ESR自旋捕集技术,以DMPO为捕捉剂,研究这种过氧化的脂质体对大鼠腹腔粒细胞(RPG)呼吸爆发的影响.结果表明,一定过氧化程度的脂质可增加促癌剂PMA刺激RPG产生的O_2~-.脂浓度为0.5mg/ml时,这种作用随充烟量的增加先不断增强,30s左右达最大值,然后又逐渐减小.空气引发的脂质过氧化对RPG呼吸爆发有相似的作用.     

气象舒适条件对呼吸系统疾病的影响

采用广义相加模型和分布滞后非线性模型,研究单个气象要素和以"通用的热气候指数"表征的多要素综合效应与北京市2009~2012年呼吸系统疾病急诊人数的暴露-响应关系,并按年龄、性别分层.结果表明,对全人群而言,高温效应即时,低温作用滞后;湿度<30%能显著增加发病风险,且效应持久;3m/s风速对应发病风险最低.少儿（≤ 14岁）受热胁迫影响最强,尤其突出高温高湿作用;成人（15~59岁）受冷胁迫影响强且滞后性;老年患者（>60岁）对冷胁迫敏感,着重防范低温低湿.采用舒适指数探讨环境对呼吸系统疾病的影响优于单要素表征,可加深对发病气象成因的理解,为科学预防、预测预警提供新思路.     

Multivariate imputation in cross-sectional analysis of health effects associated with air pollution

We demonstrate a recently developed spatial interpolation methodology in a study of the chronic effects of air pollution on respiratory morbidity. Our study uses data from the Ontario Health Study, a large survey of households in Ontario conducted for the province by Statistics Canada. The interpolation procedure imputes unobserved vectors of air pollution concentrations for individual Public Health Units, from those observed at a few fixed air pollution monitoring sites. We use logistic regression methods to assess the significance of air pollution levels based on the imputed values after modelling the relationship between binary health responses and assorted covariates such as measures of life style. Our findings prove negative; no significant relationship between chronic respiratory morbidity and air pollution is found. The imputation methodology is seen to be promising and might well be used in other such analyses.     

防霾口罩呼吸阻力的研究

通过对8种常用类型防霾口罩的实验测试,采用回归曲线分析方法得出了防霾口罩呼吸阻力随使用时间的变化函数形式,同时也通过实验数据统计给出了各种类型口罩的建议使用时长,建议N90和N95无纺布防霾口罩在空气轻度污染下使用时长不超过11~12 h,中度污染下不超过8~10 h;而棉布为面料的N95口罩在轻度污染下使用时长不超过7 h,中度污染下不超过6 h。     

Clogging of Filtering Material Systems Used for Disposable Respirators

The article shows the problem of clogging in connection with the parameters of filtering materials used in respiratory protective equipment. The results of investigations of airflow resistance changes during the depositing of dust inside the filtering material are presented. The configuration of layers differing in mass per unit area and the number of layers, were taken into consideration. For each configuration, the clogging abilities and the changes of airflow resistance as a reason of loading with dust were assessed. The analysis of tested materials confirms the hypothesis that there is an important coincidence between the properties of the material used in filtering equipment and the clogging coefficient. The results show that the filter should have a layered structure and that the outer layer should be made of a nonwoven of relatively high surface density.     

A Contribution to the Study of the Antidust Respirators’ Real Performance

In most industrial enterprises, hazardous factors are present in quantities exceeding permissible levels. Such a situation requires using antidust respiratory protection. It has been suggested, however, that filters for respirators are not assessed properly and that lab results might not be related to real filtering efficiency in industry. This article contains test results of some commercially available filtering half-masks, including the effect of loading with real dust, high humidity, high temperature, and a combination of loading with dust and high humidity on the half-masks’ performance. The results show that the effect of these factors is considerable and that a combination of loading with silica dust and exposing to high humidity can cause a complete loss of performance.     

Deposition and Resuspension of Selected Aerosols Particles on Electrically Charged Filter Materials for Respiratory Protective Devices

The primary aim of the study was to analyse the non-steady state of filtration for selected electrostatic filter materials designed for use in respiratory protective devices. The obtained results showed that the filtration process in electrostatic filters was dependent in the main on the following factors: type of the filter material, electrostatic field strength of the material, and the charge of the aerosol.

To a lesser degree the filtration process depended on the sign of the charge and the relative humidity of the air. A significant correlation was found between the increase in the penetration and the decrease in breathing resistance while the filter was being loaded.

The effect of resuspension (tearing off and re-deposition of dust agglomerates inside the filter) on the filtration process very significant. It was also observed that under certain conditions electrostatic filter materials lost their protection properties.     

Respiratory Problems of Workers in the Zarda Industry in Kolkata,India

This study was undertaken to assess the pulmonary and respiratory problems of workers in a zarda factory. A total of 70 permanent zarda workers (50 manufacturing workers and 20 office ones) were studied in a factory in Baguihati, Kolkata, India. The study included (a) completion of a questionnaire (on pulmonary and respiratory problems), (b) measurement of physical parameters, (c) spirometry and (d) measurement of peak expiratory flow rate. At the same time, the worksite was analyzed with an OSHA-recommended ergonomics checklist. Many zarda manufacturing workers complained of respiratory symptoms. Continuous exposure to the tobacco processing environment reduced the workers’ lung volume and peak expiratory flow rates. Our study indicates that zarda manufacturing workers may have respiratory and pulmonary disorders related to exposure to tobacco dust in their work environment.