Saejiw Nutjaree, Chaiear Naesinee, Sadhra Steven
School of Allied Health Science and Public Health, Walailak University, Thasala, Nakhon Si Thammarat, Thailand.
J Occup Environ Hyg. 2009 Aug;6(8):483-90. doi: 10.1080/15459620902967065.
A cross-sectional study on wood dust exposure and respiratory health effects was conducted at one of the largest rubberwood sawmills in Thailand. All workers (N = 340) from all jobs on a day shift were recruited for personal sampling. Overall, the personal inhalable dust (n = 742) and respirable dust (n = 241) of full-shift samples were collected from 27 job titles. These data were used to classify workers into high, moderate, and low exposure groups based on the concentrations found in each job. Static samples were also collected to determine the particle size distribution. Geometric means (GM) are used to present the concentrations of the rubber wood dust. Inhalable dust concentrations were clearly high, ranging between 0.2 to 59.4 mg/m3 and with GM of 4.7 mg/m3. The GM of inhalable dust in each job title enabled classification of the workers into three exposure groups: (1) high exposure; >5 mg/m3, (2) moderate exposure; 2.0-5.0 mg/m3, and (3) low exposure; 0.18-1.9 mg/m3. Among the high exposure group, the highest GM inhalable dust concentrations were found in sawing green lumber (12.8 mg/m3) and cutting dry lumber (7.3 mg/m3). The respirable dust concentrations were generally low, in the range of 0.1 to 6.0 mg/m3 with a GM of 0.5 mg/m3. The largest percentage of dust in major operations belonged to the thoracic fraction; 50% cutoff diameter was smaller than 9 mum. The size distribution of wood dust indicated a high proportion in the large particle sizes.
在泰国最大的橡胶木锯木厂之一开展了一项关于木尘暴露与呼吸道健康影响的横断面研究。招募了白班所有岗位的全部工人（N = 340）进行个人采样。总体而言，从27个岗位收集了全时段样本的个人可吸入粉尘（n = 742）和呼吸性粉尘（n = 241）。这些数据用于根据各岗位测得的浓度将工人分为高、中、低暴露组。还采集了静态样本以确定粒径分布。采用几何均值（GM）来呈现橡胶木粉尘的浓度。可吸入粉尘浓度明显很高，范围在0.2至59.4毫克/立方米之间，几何均值为4.7毫克/立方米。每个岗位可吸入粉尘的几何均值使得工人能够被分为三个暴露组：（1）高暴露；>5毫克/立方米，（2）中度暴露；2.0 - 5.0毫克/立方米，以及（3）低暴露；0.18 - 1.9毫克/立方米。在高暴露组中，锯切新木材（12.8毫克/立方米）和切割干燥木材（7.3毫克/立方米）时可吸入粉尘的几何均值最高。呼吸性粉尘浓度普遍较低，范围在0.1至6.0毫克/立方米之间，几何均值为0.5毫克/立方米。主要作业中最大比例的粉尘属于胸腔部分；50%截止直径小于9微米。木尘的粒径分布表明大粒径的比例较高。
