Hazardous materials management Exposure monitoring Hearing conservation Engineering

Hazardous materials management Exposure monitoring Hearing conservation Engineering Controls Education & training Exposure Assessment Hazard communication Administrative controls Work practice control Epidemiology Medical Surveillance Radiation Safety PPE Fig 1 Exposure assessment’s central role in industrial hygiene program management (Mulhausen and Damiano, 1998)

作业环境测定采样技术之选定 Based on Exposure Pathways Process Work Surface Air Skin Inhalation Ingestion Absorption 4

作业环境测定 l Methods (according to agents) l Physical factors l Thermal hazards: WBGT l Noise: Noise meter, Dosimeter l Chemical factors l Particle: filtration… l Gas/vapor: adsorption, absorption… 5

个人采样(personal sampling) l 为最主要之采样方法。 l 目前最常使用之采样策略包括 l NIOSH 1977之最大暴露危险群(maximum exposure risk group)采样 l 暴露者之符法性评估(compliance assessment) l AIHA之相似暴露群(SEG，similar exposure group)采样策略 l 评估劳 之长期平均暴露量(long-term average exposure assessment)。 11

符法测定（Compliance test） (NIOSH 1977 Sampling strategy) 13

符法测定（Compliance test） l Sampling concepts l Max exposure group l Worst-case l Sampling subjects l Via observation l Workers’ complains l Random sampling 14

符法测定（Compliance test） l EM => PEL => Compliance? l Problems: l The change of PELs l Representative to workers’ exposures? l Not good for dose/health-risk estimation. l …. . 15

如何决定最高暴露危险群? 定性推估模式 Qualitative predictive model 18

定性推估模式 专业判断Professional judgment l 专家系统Expert system evaluation l 推论与模拟Inference and Analogy l Q: How can you convince your customers? 19

IH Expert (or Professional) Judgment l “The application and appropriate use of IH knowledge gained from formal education, observation, experimentation, inference, and analogy. ” l Such as l Low vapor pressure l Enclosure l High ventilation rate l…

Problems associated with IH professional judgment Impossible to explain objectively l Not supported by explicit quantified facts l Not amenable to technology transfer l Insufficient to provide convincing evidence l

如何决定最高暴露危险群? 半定量推估模式 Semi-quantitative predictive model 22

化学品分级管理 （Chemical Control Banding, CCB） 23

英国物质健康危害控制要点 （Control of Substances Hazardous to Health Essentials, COSHH Essentials） 34

COSHH Essentials 35

COSHH Essentials l 1 Assign hazard group (based on Rphrase) 36

COSHH Essentials l 2 Using amount 37

COSHH Essentials l 3 Determine dustiness/volatility 38

COSHH Essentials l 4 Identify control approach 39

COSHH Essentials l 5 Find appropriate control sheets 40

德国 作场所危害物质管控计划（ Einfaches Maßnahmenkonzept Gefahrstoffe, EMKG） 41

EMKG-1 43

EMKG-2 44

EMKG-3 45

EMKG-4 46

EMKG-5 47

EMKG-6 48

EMKG-7 49

EMKG-8 50

EMKG-Tool 51

EMKG-Tool 52

其他半定量暴露危害�估方法 l Example l The Exposure Hazard Index (EHI) TI : Toxicity index (T： min) EI : Exposure index PDI : Protection deficiency index N：number of management measures PI= Types of eng. control +PPE 0~1 Source: Developing a Semi-Quantitative Occupational Risk Prediction Model for Chemical Exposures and Its Application to a National Chemical Exposure Databank (Wang et al. , Int. J. Environ. Res. Public Health, 2013, 10: 3157 -3171) 54

如何决定最高暴露危险群? 定量暴露评估 具 (Quantitative exposure assessment) 55

Reference book

Zero ventilation model

Zero ventilation model 58

Saturation vapor pressure model

Saturation vapor pressure model

Well-mixed box (WMB) model

Well-mixed box (WMB) model Room as a box with highly internal turbulent flow… Mass balance Continuous pollutant released into a ventilated space… 62

Well-mixed box (WMB) model Mass is neither created nor destroyed Qin=Qout=Q; Well-Mixed; No reaction; No sink; Zero ventilated losses… 63

Room air mass balance for contaminant A 64

Closed form solution of the CMB model 65

Forced ventilation 66

Forced ventilation 4. 4. 6. 6 67

WMB model with multiple airflows 68

Far field/near field model with a constant emission rate

Model development

Air dispersion plume models

Complete Equation For Gaussian Dispersion Modeling Of Continuous, Buoyant Air Pollution Plumes

Particle emission l Estimation is very challenging: l Particle size (dae) variation l Particle sedimentation l Coagulation

随机采样 For N=26 => n= 15 77

随机采样 For N=26 => n= 15 78

Coefficient of variation (CV) 83

Coefficient of variation (CV) 84

Coefficient of variation (CV) 85

全程单一样品采样 (Full Period Single Sample) 86 NOTE: x = X/STD

全程单一样品采样 (Full Period Single Sample) 87

全程多样本-均匀暴露 (Full period uniform exposures with multiple samples) 88

全程多样本-非均匀暴露 (Full period non-uniform exposures with multiple samples) 89

Partial period consecutive samples PPL= Partial Period Limit LCL calculation methods followed the above uniform and non-uniform exposures with multiple samples 90

全�� 定 Comprehensive exposure assessment (AIHA 1998 Sampling Strategy) 91

全�� 定 Comprehensive exposure assessment l 依据美国AIHA于1998年所提出之采样策略: A Strategy for Assessing and Managing Occupational Exposures l 强调以comprehensive的概念取代compliance。 l 为达到comprehensive之精神，采样策略必须对厂内 所有劳 、所有时间的所有暴露进行了解。 92

全�� 定 Comprehensive exposure assessment 95

随机采样 l All commonly used statistics assume RANDOM SAMPLING 105

2020/11/2 107

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一般原理与概念 General principles and concepts

现行法规 Current regulations

化学品分级管理控制使用之建议(2) l l 适用于第八条之评估及分级管理方法或 具: Modeling l l l l 无通风模式(Zero ventilation model) 饱和蒸气压模式（Saturation Vapor Pressure Model） 暴露空间模式（Box Models） 完全混合模式（Well-mixed Room Model） 二暴露区模式（Two-Zone Model） 烟柱扩散模式(Plume dispersion model: near and mid field) 其他模式 l Eddy diffusion model l EASE (estimation and assessment of substance exposure) model l Structure Subjective Assessment Method 129

Bayesian Decision Analyses 专家主观评估法(半定量) 或 过去暴露推估值(定量) 1 2 3 4 5 Bayesian 1 有限环测资料 1 2 3 4 5 修正后之劳 暴露实态 5 133 --Vadali et al. , 2009; Ramachandran, 2008

Example: Model + EM + Bayesian Decision Analysis 134

Why do we need Bayesian decision analysis? OEL=10 mg/m 3 135 Exceeding OEL? 135

Bayesian decision analysis result 136

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Introduction to. IH MOD, A new tool to aid industrial hygienists in exposure assessments 140

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The end Thanks 142

Questions? 143