Sanjel Seshananda, Khanal Sanjay N, Thygerson Steven M, Carter William S, Johnston James D, Joshi Sunil K
Department of Community Medicine, Kathmandu University School of Medical Sciences, Dhulikhel Hospital, Dhulikhel, Kavre Nepal.
Environment Science, Department of Environment Science and Engineering, School of Science, Kathmandu University, Dhulikhel, Nepal.
Ann Occup Environ Med. 2017 Mar 27;29:9. doi: 10.1186/s40557-017-0165-0. eCollection 2017.
Bricks have been manufactured in Nepal for hundreds of years and are seen as a component of Nepalese sculpture and architecture. Large quantities of hazardous materials including high concentrations of particulate matter are emitted on a daily basis from brick kilns. Exposure to these hazardous materials can lead to adverse consequences on the environment and human health. This study was conducted to estimate the prevalence of respiratory symptoms/illnesses and the magnitude of respirable and total dust exposures among Nepalese brick kiln workers.
Respiratory symptoms/illnesses were evaluated by questionnaire among brickfield workers ( = 400) and a referent group of grocery workers ( = 400) in Kathmandu valley. Work zones (WZs): green brick molding (GBM), green brick stacking/carrying (GBS/C), red brick loading/carrying (RBL/C), coal preparation (CP) and firemen (FM) were the similar exposure groups (SEGs) from where personal air samples and interviews were taken. Among brickfield workers, personal monitoring was conducted across SEGs for total ( = 89) and respirable ( = 72) dust during February-March 2015 and March-April 2016. Applying multi-stage probability proportionate to size sampling technique, 16 kilns and 400 brick workers for interview were selected. Proportions, means, medians and ranges were calculated for the demographics, samples and respiratory symptoms/illnesses. One-way ANOVA was applied to compare the significance differences of the level of particulate matter among SEGs. Bivariate and multivariate logistic regression analysis were performed to evaluate association between respiratory symptoms/illnesses and participants groups, and SEGs among brick kiln workers at 0.05 level. Statistical analyses were performed using IBM SPSS Statistics 21.
Chronic cough (14.3%), phlegm (16.6%) and bronchitis (19.0%) were higher ( < 0.05) among brickfield compared with grocery workers (6.8, 5.8 and 10.8%). Mean respirable (5.888 mg/m) and total (20.657 mg/m) dust exposures were highest for red brick loading tasks. The prevalence of chronic cough, chronic phlegm, chronic bronchitis, wheezing and asthma were significantly higher for other WZs workers ( < 0.05) compared with CP; for GBM: 22.9, 34.6, 15.0 and 7.5%; for GBS/C: 13.5, 15.8, 10.0, 8.8 and 7.5%; for RBL/C: 11.1, 17.1, 27.4, 19.0 and 11.9%; for FM: 18.4, 12.5, 28.4, 4.9 and 0.0%; and for CP: 4.9, 6.3, 13.3, 9.3 and 4.0% respectively.
High dust exposures identified in this study may explain the increased prevalence of respiratory symptoms/illnesses among Nepalese brickfield workers, warranting action to reduce exposures.
砖在尼泊尔已有数百年的生产历史，被视为尼泊尔雕塑和建筑的组成部分。砖窑每天都会排放大量有害物质，包括高浓度的颗粒物。接触这些有害物质会对环境和人类健康造成不良影响。本研究旨在评估尼泊尔砖窑工人呼吸道症状/疾病的患病率以及可吸入粉尘和总粉尘暴露的程度。
通过问卷调查对加德满都谷地砖厂工人（n = 400）和杂货店工人对照组（n = 400）的呼吸道症状/疾病进行评估。工作区域（WZ）：青砖成型（GBM）、青砖堆放/搬运（GBS/C）、红砖装卸/搬运（RBL/C）、煤炭制备（CP）和司炉工（FM）是类似暴露组（SEG），从这些区域采集个人空气样本并进行访谈。在砖厂工人中，于2015年2月至3月和2016年3月至4月期间，对各SEG进行了总粉尘（n = 89）和可吸入粉尘（n = 72）的个人监测。采用多阶段按规模概率抽样技术，选取了16座砖窑和400名砖厂工人进行访谈。计算了人口统计学、样本和呼吸道症状/疾病的比例、均值、中位数和范围。应用单因素方差分析比较各SEG中颗粒物水平的显著差异。进行双变量和多变量逻辑回归分析，以评估砖窑工人中呼吸道症状/疾病与参与者组以及SEG之间在0.05水平上的关联。使用IBM SPSS Statistics 21进行统计分析。
与杂货店工人（6.8%、5.8%和10.8%）相比，砖厂工人的慢性咳嗽（14.3%）、咳痰（16.6%）和支气管炎（19.0%）发生率更高（P < 0.05）。红砖装卸任务的平均可吸入粉尘（5.888 mg/m³）和总粉尘（20.657 mg/m³）暴露量最高。与CP组相比，其他WZ组工人的慢性咳嗽、慢性咳痰、慢性支气管炎、喘息和哮喘患病率显著更高（P < 0.05）；GBM组：22.9%、34.6%、15.0%和7.5%；GBS/C组：13.5%、15.8%、10.0%、8.8%和7.5%；RBL/C组：11.1%、17.1%、27.4%、19.0%和11.9%；FM组：18.4%、12.5%、28.4%、4.9%和0.0%；CP组：分别为4.9%、6.3%、13.3%、9.3%和4.0%。
本研究中确定的高粉尘暴露可能解释了尼泊尔砖厂工人呼吸道症状/疾病患病率的增加，因此有必要采取行动减少暴露。
