INDUSTRIAL HYGIENE PERSPECTIVE IN HEALTH SURVEILLANCE

NRG SHE CONFERENCE

10-11 July 2017

Sunway Convention Centre,

Seberang Jaya,Penang

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DR.IBRAHIM ZUBIL AB RAHMAN

OCCUPATIONAL HEALTH PHYSICIAN

OBJECTIVE

1. To explain the fundamental of IH

2. To recognise health surveillance components

3. To appreciate medical surveillance as per USECHH regulation

4. To relate IH with medical surveillance

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INTRO: OCCUPATIONAL DISEASES & IH

Exposure to chemical, physical or biological hazards can cause occupational diseases.

Occupational diseases are acute or chronic (gradual or delayed) reactions and are very diverse.

To avoid occupational diseases the exposure should be prohibited, regulated, restricted, limited or controlled by industrial hygiene practices & IH-programs.

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OSH MP 2020

Target of OSH MP 2020 – to reduce the burden of occupational diseases

Strategy- to mainstreaming industrial hygiene practice

Aim – to promote greater professionalism in work safety culture

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INDUSTRIAL HYGIENE

Industrial Hygiene is the art and science of the anticipation, recognition, evaluation, and control of environmental health hazards arising in or from the workplace.

Safety = prevention of accidents / incidents

IH = prevention of occupational illnesses

( one component of the broader spectrum of OH)

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FUNDAMENTALS OF INDUSTRIAL HYGIENE

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Basics

IH

Identification

Evaluation

Control

Identification of hazards

Theoretical assessment of

exposure

Measurement strategy

Monitoring

Evaluation results

Report

Respect hierarchy

of controls

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HEALTH SURVEILLANCE

4 in FMA , 1 in OSHA

Chemical in air

Absorption

Distribution

Biotranformation

Binding to target

organ

Adverse effects

excretion

Pathway of a xenobiotic from the environment to the target organ

Body

Expo

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Hygiene

medical

Health surveillance components

Lead in the air

- Air monitoringHealth surveillance

1. Exposure monitoring

•measuring the present of

toxicant

- air (air monitoring)

- metabolites in body

fluid/hair (biological

monitoring)

- biochemical parameters

(not toxicant/metabolite)

2. Medical monitoring

- measuring the health

effects

Blood lead

(Biological monitoring)

Symptoms

review

Physical

examination

Specific Ix

Enzyme ALA dehydratase

(bio. effect monitoring)

EXPOSURE MONITORING

One of the major component of HS(3/4 in USECHH)

Domain of IH rather than medical

Investigation specific to OH practice

An important tool that can be used to provide a reliable estimate of exposure to workplace contaminant

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EXPOSURE MONITORING

Three types

1. Environmental monitoring

2. Biological Monitoring

3. Biological Effect monitoring

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Chemical in air

Absorption

Distribution

Biotranformation

Binding to target

organ

Adverse effects

excretion

Air / Environmental

monitoring-

- On contaminated air &

on person exposed

Pathway of a xenobiotic from the environment to the target organ

Body

Expo

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Intake

uptake

effect

ENVIRONMENTAL MONITORING

Measurement and assessment of agents (physical, chemicals, biological) in the workplace to evaluate inhalation exposure/intake levels and health risks compared with an appropriate standards

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intake uptake effect

Exposure phaseToxicokinetic phase

Toxicodynamic phase

Environmental monitoring biomonitoring - Medical

survillence

chem

env

person

- BEM

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ENVIRONMENTAL MONITORING METHOD

Two stages

1. Sampling

2. Analysis

- on contaminated air@ area monitoring (static)

a) Instantaneous monitoring (direct reading)

b) Integrated or continuous sampling

- on person (Personal sampling)1. Personal exposure monitoring (integrated)

CHEMICAL MONITORING

Filter media

pump

tubing

Chemical exposurein environment

Chemical uptake

Environmentalmonitoring

Biologicalmonitoring

inhaled orswallowed

skin

throughclothing

skin

Chemical in air

Absorption

distribution

Biotranformation

Binding to target organ

Cellular/molecular changes

Adverse effects

excretion

Biological

monitoring

Pathway of a xenobiotic from the environment to the target organ

Expo

su

re m

on

ito

rin

g

Chemical in body

Intake

Uptake

Air / Environmental

monitoring-

- On contaminated air & on

person

Measurement of a substance or its metabolite in biological materials in order to provide a quantitative estimate of its uptake into the body by all routes of exposures

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Definition

CONCEPT

Biological monitoring attempts to

estimate the internal dose/uptake

Internal dose:

1.Amount of chemical recently absorbed

2.Amount of chemicals stored in one or

several compartments or in whole body

3. Amount of chemical bound to critical

sites of action21

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uptake

Toxicokinetic phase

biomonitoring

Chemical in air

Absorption

Distribution

Biotranformation

Binding to target

organ

Adverse effects

excretion

Air / Environmental

monitoring-

- On contaminated air &

on person

Biological

monitoring

Pathway of a xenobiotic from the environment to the target organ

Body

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Medical surveillance

MEDICAL SURVEILLANCE

Monitoring of a person for the purpose of identifying changes in health status due to occupational exposure to chemicals hazardous to health at regular interval

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Toxicodynamic phase

- Medical survillence

- BEM

Medical surveillance focus

at target organs effect

Basically it is a medical examination

consisting of

▪History taking

▪Physical examination specific to the target

organs

▪Investigation like CXR, blood tests, urine

tests etc.

Legal mandated medical surveillance

Medical examination stipulated by the law

OBJECTIVE OF MEDICAL SURVEILLACE

To ensure the health program and control for health risks are effective

To identify sensitive individuals

To meet legal requirement:

FMA 1967- Noise, Asbestos, Mineral Dust,

Lead

OSHA 1994- USECHH Reg.

LEGAL PROVISIONS

Medical Surveillance

When assessment indicates necessity (by assessor)

Medical surveillance to be carried out by OHD

Frequency of health surveillance every 12 months (sch:2)

Record to be kept for 30 years from the date of last entry

Accessible to employees28

➢Sec 28 OSHA

➢Part IX Reg. 27 USECHH

EXPOSURE MONITORING RESULT

INTERPRETATION

Interpretation of the air sampling and biological monitoring results

must be compared with occupational exposure standard

(OES)

o Guidance value

- concept similar to normal value in clinical

practice

Value set by the government i.e DOSH and mandatory to follow:

for airborne particles, called PEL

for absorbed toxicants (biological monitoring) called BEI

OES

3 types a) Ceiling level

b) 8 hr TWA

c) Maximum exposure limit

PERMISSIBLE EXPOSURE LIMIT (PEL)

Comparison of results with standards

Three basic conclusions

1. Exposure > PEL : Need to identify the reasons for the results & the steps required to control the exposure

2. Exposure well below the PEL – control needs to be maintained

3. Insufficient information to decide whether above or below the PEL

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DATA INTERPRETATION

EXPOSURE FOR ABSORBED TOXICANTS

1. Biological monitoring

2. Biological effect monitoring

Compare the data with Reference limits i.e Biomonitoring action levels (BALs)

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INTERPRETATION OF BIOLOGICAL MONITORING DATA

Biomonitoring action levels (BALs)

The reference values at or below which the

adverse health effects do not appear in most

workers who are exposed to the chemicals.

ACGIH (USA)Biological Exposure Indices (BEIs)

DFG (Germany)Biologischer Arbeitsstoff-Toleranz-Wert (BAT)

FIOH (Finland)

HSE (UK)

JSOH (Japan)Occupational Exposure Limit Based on Biological Monitoring (OEL-B)

BALs in different countries

• Intended as GUIDE LINE ref .value

for potential health hzd ( ACGIH)

• Represent determinants likely to

be observed to the same extent as

with inhalation exposure

• Does not make conclusion as

having disease or non disease

BIOLOGICAL EXPOSURE INDEX (BEI)

CONCLUSION

➢ Health surveillance is a joint responsibility between hygiene and medical practice

➢ OSH MP 2020 emphasizes more prominent role for IH

➢ Occupational diseases to be reduced using IH principles

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