WEBGRAFÍA

What are the hazards associated with the physical environment? These hazards result from the natural environment and from man-made structures. Unlike other system factors, physical environment hazards can be categorized relatively simply. They are summarized in Table 5.1 under the headings of climatic, structural, chemical, biological and other.

The categories given are all residual risks that may be associated with the physical environment and are not limited to the workplace. They also apply to nonwork and leisure activities, and therefore, are important in the management of public health and safety in addition to workplace safety.

Climatic hazards include extreme temperatures, which can apply excessive demands on business activities. Such conditions can have an effect on system factors, for example, processes that involve chemical or biological reactions such as fermentation are slowed when the temperature drops. Technologies may not operate as efficiently in such environments, for example, it is more difficult to start a car engine on winter mornings and machinery can overheat when it is very hot. The temperature also affects worker comfort, safety and the ability to maintain vigilance. The case involving the death of the boilermaker, given in Chapter 4, who was electrocuted as a result of prolific sweating, reinforces this point.

Infrastructure design, or in this case, the ship’s compartment, and the materials from which it was made affect the temperature by either retaining or deflecting heat. Ventilation is another important design consideration as it affects airflow that either allows hot air to be dispersed or causes it to accumulate.

Extreme temperatures can be fatal as is evident in a case involving the death of a field survey worker from exercise-induced heat exhaustion.

The incident occurred approximately 30 kilometers from Coober Pedy in South Australia on 9 February 1992.⁵ Two employees were traveling in a remote area when their vehicle became bogged down. After repeatedly freeing the vehicle and getting stuck again, they decided to set off for the Stuart Highway using maps and a compass. The distance was 20 kilometers over gently rolling, open terrain covered with small rocks. They took 5 liters of water and left the truck at about 1.00 p.m. The maximum

Table 5.1 Physical environment hazards

Climatic Structural Chemical Biological Other

(natural or infrastructural)

Extreme temperatures Elevation or heights Particles and fumes Biohazards Noise (nontechnological

• Very hot weather • Falls • Inhalation • Bacteria origin)

• Very cold weather • Falling objects • Contamination • Viruses • Storm activity and other

• Accumulation of • Parasites natural conditions

deposits on surfaces • Human interaction

Solar radiation Instability Chemicals (naturally Dangerous animals Submersion

• Sunburn • Earthquakes and occurring) • Poisonous snakes • Drowning

• Glare tremors • Inhalation • Poisonous spiders • The bends

• Loose rocks and earth • Burns • Poisonous marine life • Cramp

• Unstable infrastructure • Irritation • Harmful insects • Irritation to eyes,

• Chemical reactions • Vicious animals nose and ears

• Predators • Loss of vision and

• Nesting birds hearing

• Fatigue

• Hidden objects in water and physical hazards Precipitation and Surface conditions Radioactive substances Toxic vegetation Insufficient light moisture • Irregular surfaces (naturally occurring) • Poisonous plants • Injury to worker/s

• Rain and hail • Slippery surfaces • Radiation poisoning • Allergic respiratory • Damage to equipment

• Snow and sleet • Loose surfaces • Exposure to carcinogen reactions and/or infrastructure

• Fog and smog • Steep slopes • Chemical reactions • Allergic skin • Damage to the

• Corrosion • Extremely hot surfaces • Contamination irritations environment

• Obstruction • Extremely cold surfaces • Digestive reactions

• Weight • Glare from shiny surfaces

Lightning Confined spaces Disturbing odors

• Injury to worker/s • Restricted movement • Nausea

• Damage to equipment • Poor ventilation • Vomiting

or infrastructure • Build up of heat

(Contd)

Table 5.1 (Contd)

Climatic Structural Chemical Biological Other

(natural or infrastructural)

• Psychological discomfort

High winds Drainage

• Falling structures • Flooding

• Air-borne projectiles • Ponding of liquids

• Dust storms • Contamination

• Slippery conditions

• Erosion

Atmospheric pressure Vibration and movement

• Altitude sickness • Loss of balance

• Severe oxygen • Dizziness

deprivation • Nausea

• Travel sickness

Fire (nontechnological Access/egress

origin) • Injury to worker/s

• Bush fires • Higher consequential

• Spontaneous ignition damages following incident of flammable materials

Physical environment 129 temperature recorded on that day was 35.6°C. They stopped every half an hour for a rest and drink. After completing 10 kilometers, they rested for 15 minutes near a stream. The deceased did not use the stream water to cool down. After a further 5 kilometers, he indicated that his legs were numb and he then collapsed. The surviving employee covered the remaining kilometers in 45 minutes, got picked up by a bus and taken to Coober Pedy where he affected a rescue, which was to no avail.

The factors to be taken into account for remote area work which were highlighted by this incident were that the onset of heatstroke can occur at ambient temperatures not necessarily considered to be excessive and is more likely on humid days. In addition, it can occur suddenly and without warning. In this case, the core body temperature of the surviving employee once he reached hospital was 38°C, even after his considerable exertion in the last 4.5 kilometers of the trek. This indicates that a considerable difference in the ability of each person to handle heat stress can exist. A further factor to be considered is the amount of time such employees are given to acclimatize to the conditions.

A case involving the death of a 19-year-old exploration worker in circumstances suggestive of heat exposure⁶ illustrates these dangers further.

The cause of death was not determined by a post-mortem examination but indicators were consistent with death due to exposure to extreme heat. The case may be used to illustrate how easily and rapidly climatic factors can contribute to loss of life. The deceased was a geology student who had little previous experience in these harsh Australian conditions in which the daytime temperatures were around 41°C.⁶ The student had been suffering gastric symptoms and vomited several times on the first night in the camp. On the second day he was unable to continue work and around mid-morning began to walk back to the vehicle a short distance away. It is believed that his state of dehydration led to rapid deterioration and as a result he did not make it back to the vehicle.

These incidents highlight the need for awareness of the potential consequences of harsh climates and that each individual has different susceptibilities to such conditions. Contingency plans must also provide for medical interventions when employees become ill, and also to treat other conditions such as sunburn, that may result from working in harsh areas.

Solar radiation is a multi-risk hazard as it can lead to overheating, sunburn and also create glare that reduces worker comfort or visibility.

When drivers are travelling from Western Australia to the eastern states, for example, the sun is in direct view at sunrise and this can prevent the driver from seeing objects or animals on the road. This glare can either have a climatic origin or it can result from reflection of artificial light from the shiny surfaces in workplaces.

Other climatic factors include precipitation and moisture which create hazards by making working conditions more difficult. In the longer term it can lead to structural damage such as metal corrosion or timber rot.

Precipitation can result in the obstruction of roadways and prevent access to work areas. In combination with design faults, the accumulation of rainwater or snow can cause structures to collapse. Drainage design is therefore an important factor in preventing such risks. In addition, the

130 Productive Safety Management

natural topography or the design of infrastructure can allow flooding or ponding to occur which can lead to slippery or unworkable surface conditions. In some workplaces, such as chemical storage facilities, firms are required to erect bund walls to capture spillage. Poor design and maintenance of these structures can lead to site contamination and threats to the health of workers and the general public. Wherever there is an uncontrolled flow, either resulting from precipitation or leakage, there is also the potential for secondary damage including the erosion of slopes, roadways and other work areas.

Lightning is a hazard for workers who are outdoors during an electrical storm. This risk rises when the employee is in an open area such as a recreation field, on the sea or under trees. In fact, there were three deaths at work from lightning strikes in Western Australia in 1999 and 2000. Ten people are killed in this manner, on average, in Australia each year.⁷

High winds are also hazardous. They can destabilize natural and man-made structures causing them to collapse. They can also result in objects having kinetic energy – becoming projectiles – as is the case during cyclones/hurricanes, or they can generate dust storms that reduce visibility and in some cases, cause operations to cease. The key issue in relation to such hazards is under what conditions is it acceptably safe to continue to work and when is it not. In addition, firms can implement suppression systems to reduce the severity of such conditions. For example, some mining operators use water tanks to wet the surfaces of open-cut mines to reduce dust hazards.

Climatic conditions also include atmospheric pressure, which is a hazard when aircraft systems fail. This was evident in the previously described aviation accidents. Atmospheric pressure is also problematic for employees who have to work at high altitudes, for example, workers who commute between Antofagusta, on the coast in Chile to the Escondida mine located at the base of the Andes mountains. Variations in air pressures during flying cause travel sickness in some individuals.

The final hazard in this category is fire of a nontechnological source, such as bush fires, which are natural threats that need to be managed, particularly in the forestry industry and in areas near natural bush land.

Some of these climatic hazards are associated with natural disasters, and firms need to be aware of their susceptibility to such threats to ensure that effective contingency plans are implemented during such events.

The second category of physical environment hazards is structural factors. These can be either natural or man-made, with a significant risk in this group associated with structural height. The severity of the residual risk relates to the elevation of either the land, for example, at the top edge of an open-cut mine or cliff face, or the height of infrastructure. In addition, residual risks stem from exposure to falling objects at the base of or at a lower elevation than a nearby height. In the period 1995–1996 to 1999–

2000, falls from heights represented 9 per cent of fatalities in underground mines and 10 per cent in surface mining operations in Western Australia.⁸ The figures for death from being struck by a falling object was 9 and 30 per cent, respectively. Height-related injuries are also significant in the manufacturing and construction industries.

Instability is another significant structural hazard and can be attributed

Physical environment 131 to weaknesses in infrastructure or to geological characteristics of the workplace. Rockfalls caused 50 per cent of fatalities in the underground mines that were surveyed in the aforementioned period. Surface conditions in workplaces are a further physical characteristic in this category. These include the condition of workshop floors, for example, whether they are smooth, are nonslip or have irregularities that may be a tripping hazard, and the state of road surfaces and other areas where human resources or technologies undertake work. Some work environments have steep slopes that have to be inspected and may require barriers such as fencing to prevent rock falls from causing injury or damage. Surfaces can also become hazardous when they become extremely hot or extremely cold, for instance, railway sleepers become hot enough to fry an egg in the middle of summer in desert regions and contact with such surfaces can cause serious burns.

Likewise, infrastructure close to technologies and processes that generate heat can become dangerously hot.

The chemical composition of the physical environment can be a source of hazards. Most environmental chemicals are inert, and therefore, are not hazardous. In some cases, however, they can generate particles and fumes, for example, in some metalliferous mines sulfur dioxide is emitted from deposits of pyretic shale when it comes into contact with the air.

This is a hazard for workers if inhaled, causing irritation of the eyes, nose and throat. When it rains this sulfur dioxide becomes sulfuric acid. Acid mine drainage can have a negative impact on the environment.

Infrastructure and site design can be used to compress residual risks.

For example, the layout of buildings affects ventilation and the dispersion of particles and fumes from processes and technologies. One of the areas of current investigation in OHS management is ‘sick building syndrome’

(SBS), defined by the World Health Organization:

as an extra frequency of irritative symptoms from the eyes, nose, throat and lower airways, skin reactions, unspecific hypersensitivity reactions, mental fatigue, headache, nausea or dizziness while in a particular premises.⁹

More than 50 per cent of Australian employees work in office environ-ments with approximately 10 to 30 per cent of inhabitants being affected.

Research indicates that this does not necessarily increase absenteeism but it is believed to reduce productivity. Biohazards, such as Legionnaire’s disease, are a further risk factor in these environments. The Legionnella bacteria may multiply in and are then spread by air-conditioning systems.¹⁰ The disease results in chronic lung infection and can cause death.

There are a number of industries, including farming, abattoirs, clinical pathology and medicine, where biohazards are a major residual risk.

Biohazards include bacteria, viruses and parasites. Within this category are also insect-borne diseases such as malaria, which are a health risk, for example, for workers commuting between western countries and Asia on a fly-in fly-out basis. Employees working in the natural environment can also be exposed to dangerous creatures, such as poisonous snakes and spiders, and vegetation that can lead to skin irritation or contact dermatitis. Some workers may also have reactions such as asthma and hay fever to air-borne allergens.

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The remaining physical environment hazards do not fit clearly into the aforementioned categories. These include noise, which can result from natural processes or human activity, that cause the worker to be distracted from the task. More commonly, however, this hazard is associated with technology not the physical environment. Workplace design has an effect on the dispersion of noise. Confined spaces cause noise to reverberate whereas open spaces allow the noise to dissipate.

Water is a hazard in a number of ways – precipitation, as a flow, accumulation, as a conductor and through submersion. Some jobs require the worker to be submerged, such as lifesavers and swimming pool attendants, resulting in exposure to these residual risks. In the case of divers who inspect and repair deep-sea oil rigs, submersion can cause the ‘bends’, which is a potentially fatal condition resulting from the build-up of excess gases in the bloodstream.¹¹ In addition, submersion reduces the person’s visual and auditory receptiveness. This hinders hazard identification and prevents effective communication, for example, people have died or been injured as a result of diving into shallow water without inspecting it for sub-surface objects. Other physical hazards such as aquatic weeds can cause people to become entangled and drown. Work activities carried out in water also lead to fatigue or physical degradation so therefore, the length of time that the activity is undertaken has an effect on the risks involved.

Table 5.1 also identifies insufficient light as a source of risk. This increases considerably the risks of injury and damage regardless of whether the activity is undertaken at work, at home or in a public place. Inadequate lighting occurs as a result of nightfall, unfavorable climatic conditions, the physical environment itself such as in underground mines, and from poorly illuminated workspaces. The problem is a significant issue in 24-hour operations, and firms have to make decisions regarding the extent to which resources are allocated to provide adequate illumination according to the tasks undertaken in an area. Artificial light has two cost factors.

These are capital outlay for the installation of lighting systems and the on-going costs of electricity. The firm has to determine the level of lighting it provides to various workplaces and other areas, to ensure that employees have sufficient visibility to avoid hazards and to work safely. Lighting is a significant environmental factor in reducing risk and also affects the process of ‘tricking’ the body into maintaining function during normally inactive hours of the day. As a result, it is important to provide adequate lighting in operations that work shift rosters.

Disruption of circadian rhythms through work schedules means not only that people are expected to be awake and active at the inappropriate time in the cycles, but also that environmental factors (like light and dark) that keep the individual’s cycle on track are out of kilter.¹²

Accidents resulting from poor visibility happen very easily. For example, it was the primary cause of an incident involving an open-pit mine production operator who suffered a dislocated shoulder and bruising to his hip and back when he stepped into a three meter cavity in the berm.¹³ (A berm is a flat portion or step in an open-pit mine wall left by design

Physical environment 133 to catch loose rocks falling from upper levels of the wall.) The worker was running out levels near an excavator at night and could not see the cavity caused by blasting. Two light towers lit the area but were insufficient and the operator was not carrying a torch. He was not aware of the hazard because it was not visible. Applying the four-fold strategy this accident could easily have been avoided. Appropriate strategies could have included:

(1) Corrective action involving the erection of barriers around the cavity;

(2) Maintenance strategies including work practice improvements such as compulsory use of torches or helmet lights in poorly illuminated work areas;

(3) Management of residual risk in the short term through training that encourages vigilance in these hazardous work areas;

(4) Compression of residual risk using capital expenditure to improve lighting in such work areas.

Poor lighting reduces visibility, and in combination with other environmental factors, such as unfavorable weather and road surface conditions, can create a situation of even higher risk. For example, a case involving a mobile plant incident at an open-pit mine illustrates this combined effect. A truck driver was reversing his truck through a 1.5-meter high windrow (protection barrier made up of loose rock) at a waste dump when he became bogged down because he could not clearly see the windrow and road surface conditions. Fortunately, no damage or injuries resulted on this occasion. The incident occurred because the illumination from the light tower was obscured due to heavy rain and the shadow of two other trucks at the site.¹⁴ Combinations of physical

Poor lighting reduces visibility, and in combination with other environmental factors, such as unfavorable weather and road surface conditions, can create a situation of even higher risk. For example, a case involving a mobile plant incident at an open-pit mine illustrates this combined effect. A truck driver was reversing his truck through a 1.5-meter high windrow (protection barrier made up of loose rock) at a waste dump when he became bogged down because he could not clearly see the windrow and road surface conditions. Fortunately, no damage or injuries resulted on this occasion. The incident occurred because the illumination from the light tower was obscured due to heavy rain and the shadow of two other trucks at the site.¹⁴ Combinations of physical