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Crystalline Silica and RSP Control Methods Effectiveness during Concrete Grinding

混凝土研磨过程中结晶二氧化硅和 RSP 控制方法的有效性

基本信息

批准号：
7302577
负责人：
FARHANG AKBAR-KHANZADEH
金额：
$ 18.54万
依托单位：
UNIVERSITY OF TOLEDO HEALTH SCI CAMPUS
依托单位国家：
美国
项目类别：
财政年份：
2007
资助国家：
美国
起止时间：
2007-09-01 至 2009-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7302577
关键词：
Crystalline Silica RSP Control Methods

项目摘要

DESCRIPTION (provided by applicant): Concrete surface grinding generates one of the highest levels of crystalline silica dust in the construction industry, exposing concrete grinders to unacceptable levels of this highly toxic chemical linked to a variety of respiratory and other diseases. The proposed study, a follow up of our recently completed pilot project funded by the National Institute for Occupational Safety and Health (NIOSH) through the Center to Protect Workers' Rights, covers multiple NIOSH NORA priority areas: intervention effectiveness research, chronic pulmonary diseases, control technology and exposure assessment. This study's long-term goal is to characterize/prevent silica dust exposure during construction activities. It's short-term goal is to determine the feasibility, limitations and effectiveness of additional available dust control methods in enhancing existing dust control methods during concrete grinding. Our pilot study confirmed previous studies' findings, including our study in 2002, that the commonly used approaches do not reduce silica dust to acceptable levels. The proposed study will demonstrate the effects of major relevant influencing factors and will reveal the combinations of those factors that effectively control silica dust. The study will be performed in a controlled environment (a field laboratory) to collect data. Silica dust sampling parameters (factors) will be as follows: (a) grinding techniques: uncontrolled 1 (conventional-grinding), controlled 2 (wet-grinding and ventilated- grinding); (b) grinder diameter sizes: 3 (4.5-inch, 7-inch and 9-inch); (c) general ventilation position: 2 (on, off); (d) sampling time set up: 3 (conventional- grinding 5,15, 25 min, wet-grinding 30, 45, 60 min, ventilated- grinding 45, 60, 90 min); (e) control method flow-rate: conventional-grinding 1 (0, no water or airflow), wet- grinding water flow 3 [0.2, 0.4, 0.8 L/min/inch diameter], and ventilated-grinding airflow-rate 3 (0.25, 0.50, 1.0 L/min/inch diameter). Thus, the (1 x 3 x 2 x 3 x 1) factorial design applies to uncontrolled conventional- grinding and the (2 x 3 x 2 x 3 x 3) factorial design applies to wet-grinding and ventilated-grinding. At each factor level, 2 personal samples (replicate) will be collected and their average value will be reported as the silica concentration for that factor level. The total resulting number of air samples will be 252. For quality control, 28 blank, 30 background and 20 bulk samples will also be collected. Multiple analyses of variance will be used to analyze the data to find the desired combination of factors.

描述(申请人提供)：混凝土表面研磨产生建筑行业中最高水平的结晶二氧化硅粉尘，使混凝土研磨机暴露在这种与各种呼吸道和其他疾病有关的不可接受的剧毒化学物质中。这项拟议的研究是我们最近完成的由国家职业安全与健康研究所(NIOSH)通过保护工人权利中心资助的试点项目的后续行动，涵盖了NIOSH Nora的多个优先领域：干预效果研究、慢性肺部疾病、控制技术和暴露评估。这项研究的长期目标是确定/防止建筑活动中的二氧化硅粉尘暴露。其短期目标是确定其他可用的粉尘控制方法在增强混凝土粉磨过程中现有粉尘控制方法的可行性、局限性和有效性。我们的初步研究证实了以前研究的结果，包括我们在2002年的研究，即常用的方法不能将二氧化硅粉尘减少到可接受的水平。拟议的研究将展示主要相关影响因素的效果，并揭示有效控制二氧化硅粉尘的这些因素的组合。这项研究将在受控环境(现场实验室)中进行，以收集数据。二氧化硅粉尘采样参数(因素)如下：(A)研磨技术：无控制1(常规研磨)，控制2(湿式研磨和通风研磨)；(B)粉碎机直径：3(4.5英寸、7英寸和9英寸)；(C)一般通风位置：2(开、关)；(D)采样时间设置：3(常规研磨5、15、25分钟、湿式研磨30、45、60分钟、通风研磨45、60、90分钟)；(E)控制流量：常规磨削1(0，无水或气流)，湿磨水流量3[0.2，0.4，0.8 L/分钟/英寸直径]，通风磨削风量3(0.25，0.5，1.0L/分钟/英寸直径)。因此，(1x3x2x3x1)析因设计适用于无控制常规磨削，(2x3x2x3x3)析因设计适用于湿法磨削和通风磨削。在每个因素水平，将收集2个个人样本(重复)，并将其平均值报告为该因素水平的二氧化硅浓度。由此产生的空气样本总数将为252个。为了质量控制，还将收集28个空白样品、30个背景样品和20个散装样品。将使用多重方差分析来分析数据，以找到所需的因素组合。