CONCENTRATION AND SIZE OF AIRBORNE PARTICULATES IN WOODWORKING SHOPS

ABSTRACT Wood secondary processing operations generate large amounts of airborne particulates. Inhalation of this material can lead to the development of work-related respiratory diseases. The Brazilian legislation does not define threshold limit values for airborne wood particles, and local studies are required to provide a technical basis for establishing these limits by regulation. This study aimed to determine the concentration and size of airborne wood particles of Eucalyptus spp. in woodworking shops. Analysis of the concentration of airborne particles was carried out using a gravimetric sampling pump and collector filters. The size of airborne particles was determined using microscope slides and an optical microscope coupled to an image capture system. Air samples were collected near different machines (belt sander, table saw, and band saw) at five woodworking shops located in the state of Espírito Santo, Brazil. Of the three machines, the belt sander produced the most harmful type of particulate matter: the small size of these particles allows their deposition deep into the respiratory tract. Particulate matter was above the threshold limit value established by international standards. To prevent the risk of severe health effects, there is an urgent and imperative need to reduce worker exposure levels (by the use of collective and personal protective equipment) as well as for the implementation of specific regulations that define particulate exposure limits for the wood sector in Brazil.摘要：木材二次加工作业会产生大量空气传播颗粒物，吸入此类物质可引发职业性呼吸道疾病。巴西现行法规尚未明确空气传播木材颗粒的阈值极限值（threshold limit values），因此需开展本地研究，为通过监管制定此类限值提供技术依据。本研究旨在测定木工车间内桉属（Eucalyptus）木材产生的空气传播颗粒物的浓度与粒径。研究采用重量法采样泵与采集滤膜开展空气颗粒物浓度分析，通过载玻片与搭载图像采集系统的光学显微镜测定颗粒物粒径。研究人员在巴西圣埃斯皮里图州的5家木工车间内，于带式砂光机、台锯及带锯三类不同作业设备附近采集空气样本。三类设备中，带式砂光机产生的颗粒物危害最为显著：其产生的颗粒物粒径极小，可深入沉积于呼吸道深处。实测颗粒物浓度超出了国际标准规定的阈值极限值。为防范严重健康损害风险，亟需通过集体防护与个人防护装备降低作业人员的暴露水平，同时亟待出台针对巴西木材行业的颗粒物暴露限值专项监管法规。