Occupational Health and Safety in Employment

3.10 MONITORING WORKPLACE EXPOSURES AND HEALTH

PURPOSE

To provide procedures for baseline and ongoing environmental and personal health monitoring where it is required in relation to exposure to any job-related health hazard. The monitoring will be appropriate for assessing if an exposure is a significant hazard to health or for detecting changes in the individual's health that are known to be associated with exposure to the particular hazard.

BACKGROUND

A fundamental goal of any occupational health programme is to prevent occupational disease by the elimination of exposures or by their control to levels believed to be safe. Where hazards to health exist, they need to be measured, assessed in terms of their significance, and controlled at source. The Health and Safety in Employment Act requires that when there is a significant hazard that cannot be eliminated or isolated, an employer must, in addition to minimizing the hazard, monitor:

1. the exposure of the employee to the hazard; and
   
2. with the employee's consent, their health in relation to exposure to the hazard.

Monitoring may involve environmental measurements (e.g. air or dust sampling, sound levels etc.) or direct health monitoring of individuals (e.g. blood, urine, lung function tests).

When environmental monitoring is carried out it is important to ensure that:

1. all samples are representative of the process under investigation;
   
2. the method of sampling is appropriate;
   
3. the standards against which any results are assessed are appropriate; and
   
4. the interpretation applied to the results is appropriate.

Health monitoring may be required for the following staff members:

1. where there is an identifiable disease or health effect that may be related to the exposure;
   
2. where there is a reasonable likelihood that the disease or health effect may occur under the particular conditions of work; and
   
3. there are valid techniques for detecting the indicators of the disease or effect.

In some cases it may be appropriate for health monitoring to be carried out for students (e.g. graduate students working in research laboratories).

DEFINITIONS

Monitoring is action taken to determine the current state of a workplace, or staff member in relation to a hazard. Examples of the types of hazard that can be monitored would include:

• Physical agents - noise, vibration, ionizing and non-ionising radiation, ergonomic factors;
  
• Chemical agents - gases, vapours, dusts, liquids (e.g. organic solvents, lead);
  
• Biological Agents- micro-organisms, (e.g. bacteria viruses and fungi), animal products or samples, some plants.

Workplace Exposure Standard (WES) means any exposure listed in the Workplace Exposure Standard publication currently available in New Zealand. Workplace Exposure Standards are defined for both short-term effects (WES ceiling and WES short term exposure limits) and long-term effects (WES time weighted average limits).

REFERENCES

Health and Safety in Employment Act (1992), Regulations (1995) and Amendments. NZ Government, Wellington, NZ

Approved Code of Practice for the Management of Substances Hazardous to Health in the Place of Work. OSH Service of the Department of Labour, Wellington, 1997

Guidelines for Workplace Health Surveillance OSH Service of the Department of Labour, Wellington, 1997

Workplace Exposure Standards and Biological Exposure Indices for New Zealand. Department of Labour.

AS/NZS 2243.3 2002 Safety in Laboratories Part 3. Microbial Aspects and Containment Facilities

Health and Safety Policies and Procedures Manual. University of Waikato, 2002;

• Section 1 Accountability;
  
• Section 2.3 OOS Prevention;
  
• Section 3.5 Hazard Management;
  
• Section 3.6 Infectious Diseases Commitment Statement,
  
• Section 3.7 Management of Hazardous Substances.

RESPONSIBILITIES

Line Managers (e.g. Chairpersons, Heads of Departments) are responsible for implementing hazard management procedures in every work area under their control, (as outlined in Section 1 of the University's Health and Safety Policies and Procedures Manual). Where appropriate, environmental and health monitoring must be included as part of those responsibilities.

Note: Environmental and/or personal health monitoring should be included in the "Control" column on the standard form for the University's Hazard Management documentation when appropriate for each work area.

PROCEDURES

Where a work activity or process involves substances hazardous to health (i.e. cadmium, inorganic arsenic, isocyanates, lead, mercury, 4,4-Metylene bis (2-chloroaniline), organophosphate pesticides and electroplating involving chromium or cadmium), then the OSH "Approved Code of Practice for the Management of Substances Hazardous to Health in the Place of Work" should be followed. The supporting booklet, "Guidelines for Workplace Health Surveillance" should also be followed where the assessment indicates a requirement for personal health monitoring.

Where there is any potential for exposure to micro-organisms or other biological risk materials, AS/NZS 2243.3 (2002) should be consulted to determine the potential pathogenicity of the organism or material and ensure that the relevant work procedures are known and followed.

Where a workplace activity involves other known hazards to health, then the line manager (e.g. Chairperson, Head of Department) is responsible for arranging for any environmental monitoring. The results must be documented and the results made known to staff members (and students) who may be exposed to that hazard. The OSH publication "Workplace Exposure Standards" contains the recommended guidelines for assessing the adequacy of measures taken to limit exposure to approximately 600 airborne substances in the workplace. It is important to note that in most situations the aim should be to achieve levels of exposure considerably below the Workplace Exposure Standards.

Where an assessment has established that there is a significant hazard to health that cannot be eliminated or isolated, then health monitoring will be required. Health monitoring may be achieved through pre-employment procedures and ongoing monitoring.

Pre-employment procedures.

Line managers are responsible for:

• checking the information provided in the "Application for Employment" form to assess if potential staff members have stated that they are physically and medically fit to perform the duties for which they have applied before the appointment is finalized. If further pre-employment health screening is required, managers will consult their Human Resource Advisor. A request for a baseline test in relation to a particular hazard may sometimes be warranted, e.g. hearing loss.

Ongoing Monitoring

Line managers are responsible for:

• taking a precautionary approach and monitoring that the correct procedures are being followed. For example, where exposure to infectious micro-organisms is likely, and if an appropriate vaccine is available, then vaccination may be required (see the Infectious Diseases Commitment Statement);
  
• asking employees about discomfort (e.g. when using computers for long periods as per Section 2.3 of the Health and Safety Policies and Procedures Manual) or in relation to manual handling tasks such as lifting, bending etc.). Responses should be recorded for future reference;
  
• following up accident and incident reports and investigations;
  
• providing for medical tests by a suitably qualified external provider and recording the results. This would apply for the following:
  • audiometry (for staff exposed to noise levels above 85dBA or those required to wear any form of hearing protection);
    
  • eyesight tests (for staff exposed to visual hazards);
    
  • spirometry, other lung function tests or chest X-ray (exposure to welding fume, oxides of nitrogen, substances associated with occupational asthma or exposure to asbestos dust);
    
  • blood tests (exposure to hazardous substances that are detectable in blood, exposure to animal bites or urine, or exposure to ionizing radiation. If particularly pathogenic micro-organisms are used it may be necessary to store a pre-exposure serum sample to use as a reference should serious infection occur);
    
  • urine tests (for those exposed to hazardous substances detectable in the urine, e.g. arsenic, n-Hexane, MEK, mercury);
    
  • other tests where appropriate in relation to the identified hazard e.g. diving; and
    
  • following a critical incident, or at the time of termination of employment (where appropriate).

OUTCOMES

Where there is a current Workplace Exposure Standard, environmental monitoring is carried out to ensure that the controls for any significant hazard to health are effective (i.e. there will be freedom from adverse health effects).

Employees at risk from workplace hazards to health are monitored to establish that workplace hazard controls are effective. The information relating to exposure, work and medical history, and signs and symptoms of exposure will be collated and interpreted by a person who has an understanding of both the work activities and occupational health practice (usually a medical practitioner with experience in Occupational Health, or an Occupational Health Nurse). The Health and Safety Co-ordinator will be provided with the results of all tests (to be kept on the individual's personal file). Where an abnormal result indicates that a hazard control is not effective, then the result may be used (with the informed consent of the individual) as a basis for improving the hazard control mechanism.

Each person who participates in environmental or health monitoring will be fully informed of the results of the tests that relate to their work.

Note: The OSH publications may be downloaded free from the OSH site at
http://www.osh.govt.nz/order/catalogue/index.shtml