TIM CARTER, CONTRIBUTIONS FROM BOB BRIDGER; MARGARETHA HOLTENSDOTTER LÜTZHÖFT AND VIVEK MENON
Seafarers and especially those working on fishing vessels are at a considerably greater risk of injury than those working ashore. This section reviews the major causes of injuries at sea and identifies some of the preventative measures that are available. The problems of managing injuries at sea are also considered.
This section does not set out to be a comprehensive review of injury at sea. Its aim is to give readers an overview to enable them to participate in discussions and joint problem solving with others working in this field.
E.3.2 Sources of data on injuries in seafarers and their limitations.
Event reports are the usual source of information about injuries. These may be required by maritime accident investigation authorities or by ship operators or their insurers. Case reports can be valuable if a case has been investigated in detail and lessons from it identified. Maritime accident investigators in a number of countries produce such case reports, either as a result of their investigations into a major incident or as summaries of the event reports they receive. Companies or insurers may do the same, although the latter often have more information about the financial consequences of an event, than about causation. Academic investigators may mount studies of injury incidence and causation but most of the available data comes from official sources such as maritime authorities.
The source data on injuries is heavily dependent on assiduous reporting by ship’s officers, with or without the prompting of seafarers or their safety representatives. There can be situations, such as company incentive schemes for safety performance that encourage under-reporting. Considerations about insurance or compensation may also lead to the miss-attribution of the cause of an injury to a non-controversial one, rather than one that the ship operator may have to assume liability for. Individuals may also not report injuries for fear of criticism or a threat to their job.[i]
The pattern of reports is dependent on the criteria for inclusion, for instance which locations are covered, and the reporting criteria used: fatal, requiring hospital admission, unable to work for more than three days etc. Measures of incidence also need to be analysed separately from measures of the duration of incapacity. Incidence measures depend on the reliable documentation of the population at risk; something that is difficult with mobile populations like seafarers or those who are self-employed and often only work of a limited number of days a year, such as fishers. [ii] These population measures need to be handled with caution as a seafarer will spend part of their day working and exposed to one pattern of injury risks, another part on board but still adjacent to the workplace and with some time engaged in work tasks in port. Additional information can be found in Ch xxx.
Fatal accidents in merchant seafarers are the subject of statutory notification procedures in many countries and most investigations have used such information as the basis for their analysis. Probably the longest series of consistent analyses come from the UK, where the rate of fatal accidents in merchant seafarers dropped from 208 per 100,000 person years in 1921 to 11 per 100,000 in 1996-2005.[iii] During this time, ships, and therefore risks, changed hugely. Around 50% of fatalities in most studies arise from ship disasters.[iv] There are large differences in reported fatality rates between countries and much of this is likely to be explained by different inclusion criteria for reporting. For example, whether fatalities while travelling to or from work are included. Fatality rates among seafarers are far higher than the average for onshore workers, sometimes as much as 10 times.[v]
Studies of non-fatal injuries use data from a variety of sources, for example, statutory notifications, insurance claims and company records. The downward trend is less clear than for fatal accidents, and most studies are essentially limited to personal injury records, excluding ship disasters. Confidential near miss reporting systems can also provide important information on the nature and frequency of situations that have the potential to lead to injury or damage.[vi]
Ratings usually have a considerably higher incidence of injuries than officers do.[vii] As on land, slips, trips and falls are major causes of injury, with movement between ship and shore a significant contributor.[viii] Human factors, notably fatigue, are probably just as important antecedents to personal injuries as they are to ship disasters.
Injury rates are generally even higher in the fishing industry than in merchant seafarers. The industry uses a huge range of vessels, from large factory trawlers to dugout canoes. Each type of vessel and method of fish catching has its own pattern of injury risks.[ix] Factors such as weather, water temperature and the presence of harmful or predatory marine life also influence these risks. Fishing is consistently shown to be among the highest risk of industries and more information on the fishing industry can be found in Ch xxx.
Fatality rates in developed countries, mainly in NW Europe where most studies have been conducted, have reduced in recent decades.[x] Around half of all fatalities were attributable to vessel disasters. Some of these were a consequence of instability either from unsafe modifications or from fishing activities. However, it is likely that human factors and especially fatigue, which is commonly at high levels in fishing crews, are major contributors.[xi]
Unfortunately, there is no available evaluation of risks on the large number of boats in use in the developing world that are almost certainly less safe. However, it is clear that fishing everywhere has a high risk of accidents and that there is considerable scope for better prevention, given the resources and will to intervene.
Fish farming has its own pattern of injuries, some from the use of small boats and some from diving incidents but the introduction of effective risk management strategies has been shown to be effective. For example in Alaska, fatal accident rates fell from 4.2 per 1,000 person years in 1980-4[xii] to 1.16 in 1991-8[xiii]. During this period part of the fleet was renewed with larger, safer vessels and better personal protection including immersion suits with radio beacons were introduced. These provide built in insulation and buoyancy and aid location of the casualty.
188.8.131.52 Summary of information on injury risks
- Seafarers have high overall rates of injury compared with most other occupations, with fishing as the most extreme.
- Vessel disasters, occupational injury and injury in non-occupational settings all contribute to the total.
- The available data are limited, with none from other than developed countries with established maritime regulation and academic centres
- There are problems of comparability because of different recording criteria
- There are very few follow up studies to explore the consequences of injury for the person affected, their rehabilitation and subsequent working ability.
E.3.3 Injury causation
BOB BRIDGER, MARGARETHA HOLTENSDOTTER LÜTZHÖFT
The final release of energy leading to an injury is the last stage in a chain of events. There are a number of approaches to the analysis of causes in widespread use and which are applicable to maritime settings. Some are concerned with attributing blame or liability for the event, others are tools that can aid the understanding and analysis of the events leading up to the injury with the aim of prevention and others are used as a theoretical basis for approaches to prevention. These are noted here because other professional groups commonly use them and familiarity with them will aid discussions.
- Swiss cheese model (Reason) http://en.wikipedia.org/wiki/Swiss_cheese_model
- Haddon’s matrix
- Fault tree analysis
- Hazam and hazop studies http://en.wikipedia.org/wiki/Hazard_and_operability_study
- Heinrich’s triangle http://en.wikipedia.org/wiki/Herbert_William_Heinrich
- The iceberg effect – safety economics //www.ilo.org/wcmsp5/groups/public/@ed_protect/@protrav/@safework/documents/publication/wcms_110381.pdf">http://www.ilo.org/wcmsp5/groups/public/@ed_protect/@protrav/@safework/documents/publication/wcms_110381.pdf
- Safety culture and behaviourhttp://en.wikipedia.org/wiki/Behavior-based_safety
E.3.4 Injury prevention and risk management on board ship. Health related aspects
The principles of preventing navigational errors leading to ship disasters such as grounding or collision are beyond the scope of this book. More information on ship incidents is available in Ch xx. The specific contributions of health professionals in preventing such events includes:
- responsibility for assessing the medical aspects of fitness for those undertaking safety critical duties as well as for identifying those likely to have an excess risk of injury associated with the strains of prolonged periods of work at sea.
- advice on human factors aspects of navigation, for example, the visual requirements and the task demands of work on a ship’s bridge.
- recommendations on crewing levels to avoid problems such as fatigue and insufficient time for safe handover between watches.
The prevention of work related injury to individuals at sea is based on similar risk assessment approaches to those adopted ashore. Such work needs to be based on an assessment of hazards and risks in the working environment, and the implementation of steps taken to mitigate them. Further information is available in Ch xx. Practical difficulties arise because of the conditions at sea, with moving decks, slippery surfaces and unguarded or enclosed spaces. Another feature is the command structure on board. This can lack the separate safety supervision functions that are common elsewhere. Hence the safety culture on board will be heavily dependent on that adopted by a few senior officers. They are likely to be under economic and operational pressures that may count against ensuring that precautions and training are adequate. In addition, where crews are multi-cultural, different sub-groups may each have their own conceptions of risk and safety that may be incompatible.
When injuries arise at sea, there is usually no immediate access to specialised treatment facilities. Maritime disasters may require evacuation of a ship using lifeboats or other aids and this can lead to the risk of hypothermia and drowning. Modern evacuation systems go some way towards minimising such risks but, particularly in the safe evacuation of passengers, some of whom may have mobility and other limitations, physical strength and a positive psychological attitude are important. Here health professionals may play a part in determining criteria that will ensure that seafarers are capable of such tasks.
The shipboard environment
Other emergencies such as a fire on board or loss of power, place high physical and psychological demands on crew. In these situations, the ship will be entirely dependent on the training and capabilities of those who undertake such tasks. Firefighting often requires the use of breathing apparatus that is heavy and where the duration of the air supply will depend on breathing rates that are usually higher in the unfit, the overweight and those who are highly anxious. Fitness criteria used at selection, or more practically meeting the demands on a firefighting training course are important ways of reducing the risk of inability to respond in an emergency.
Non-working time may also be taken at sea and here there are a range of more domestic risks, such as sports injuries, falls and burns from food preparation. Onshore injury risks while in port or during leave periods may also be domestic in character, but their frequency may be raised by the use of alcohol and the location of the vessel in a hazardous harbour area. Inadequate arrangements for access to vessels, especially fishing vessels, are a significant cause of injuries in port.
Occupational injuries in fishing are a particular problem because of the conditions of work, including
- deck based casting and hauling of gear,
- the congested presence of fast moving and heavy cables, beams and weights as well as the winches used to move them.
- the small size of the vessels meaning they respond rapidly to sea conditions
- slippery decks from fish and other marine debris.
E.3.5 Common Maritime Injuries
Below are examples of some commonly encountered injury risks that have specific maritime features. Almost all of the range of injuries encountered ashore can also occur at sea, from eye injuries from flying projectiles when paint chipping or hammering, through knife wounds in the galley during food preparation, to falls from bed in rough weather. The feature common to all is the difficulty of access to treatment and care whilst at sea, and hence a higher risk of long-term adverse outcomes than may be the case ashore. Additional information on medical care at sea can be found in Volume xx.
Slips, trips and falls
The surfaces of a vessel may be wet, slippery, cluttered, moving and uneven. All these features increase the risk of slips and trips, which will commonly lead to falls to deck level. If they occur at an unguarded edge, such as the side of the vessel, an open hold or access opening on a container, or at the top of a companion way(flight of stairs), they may result in a fall from a height that is likely to result in severe injury.
Falls from a vessel or between a ship and a quayside carry the additional risks of hypothermia, drowning and crushing, as does being swept off the deck by the sea. Rescue can be complex and involve other crewmembers in the risks of launching a boat and picking up the person. This is a particularly common risk in fishing as gear is handled over the side of the boat and, should entanglement occur while it is being run out, there is a risk of being drawn overboard with it. Historically, many of the falls between ship and quay arose when seafarers returned to a vessel when affected by alcohol.
Falling and swinging objects
A ship is a multi-layered environment, where activities on upper decks, masts or derricks can pose risks to those below if, for instance, tools are dropped or if lifting gear is swinging. Such risks are particularly common during cargo handling as loads are lifted and moved or fastenings are attached.
Work in enclosed spaces
Enclosed spaces may pose risks from their lack of access and ventilation. They include cargo areas, such as the tanks on a liquid bulk carrier or spaces adjacent to cargoes that change the composition of the air. Spaces in the body of the ship, such as fuel stores, chain lockers and access routes to inspect the extremities of the hull pose similar risks. Atmospheres may be inflammable or explosive, deficient in oxygen or contaminated with toxic gasses. Hence, fire, explosion, asphyxiation and poisoning can arise. Additional information on chemical risks is available in Section xxx.. If a person is harmed in an enclosed space, it can be a complex and dangerous task to remove them.
Work on board in enclosed spaces is an important and largely avoidable cause of serious and fatal injuries, sometimes involving more than one worker or harming inadequately protected rescue personnel who enter a space to try and help someone in distress. Detailed methods for safe working practice have been published by IMO and industry bodies. These cover aspects such as:
- gas freeing and testing the atmosphere in space for toxic or fire risks and to detect low levels of oxygen
- protective clothing
- breathing apparatus use
- permits to work to ensure that new hazards are not created when work is in progress
- back up and supervision to identify is a person who has entered the space is distressed from working conditions, injury or sudden illness
- arrangements for safe rescue if problems arise, including immediate access to protective clothing and breathing apparatus.
Acute chemical incidents
Chemical substances, both in cargo and those used on board as cleansing agents, scale removers and solvents, can cause acute injury. This may be by inhalation (gassing), often in a confined space, by corrosion of the skin and in particular by damage to the eyes. Additional information on the risks of chemical substances can be found in Ch xxx.
Burns and electrical injuries
The commonest locations for thermal burns to occur on board are in the engine room, and they usually result from flames, explosions or scalding and in the galley, where they result from contact with hot fluids or objects during cooking.
Chemical burns from corrosives have many of the same features as thermal ones.
Electrical injury will be associated with power generation and use.
Work in port and other manual handling tasks
The risks of slipping, tripping, falling and being struck by objects have already been noted. Some types of cargo handling such as securing containers are known to pose a high risk. Despite mechanical aids there is still much manual handling. Tasks include the movement of warps and springs when mooring, the loading of food and other requirements that are not done by the main cargo handling equipment. Movement of hatch covers may also involve hard physical work. Much of the damage is long term, but sudden strains and unexpected movements can cause acute musculoskeletal injury. More information on musculoskeletal injures can be found in Ch xx.
Hawsers and winches
Both merchant and fishing vessels make extensive use of ropes, cable and hawsers. Particular risks include the parting of a hawser, especially a steel one, where the broken end may move around with high velocity, unspinning as it moves. This can result in major injuries to those who are in its path.
Where cables are being winched in or out there will be pinch points between the winch or capstan and the coiled cable. These are often close to the locations where a crewmember is positioned, and part of their task may be to ensure that the cable coils correctly – with the temptation of intervening by hand in the event of a problem leading to hand and finger injuries. Such incidents are particularly common with the repetitive hauling tasks in fishing, often undertaken by tired seafarers on a slippery and congested deck.
Fishing injuries and poisonings
Personal injuries in fishing have many causes. A number have already been referred to. There is a high incidence of hand injuries; from fishing gear, marine debris and knives used in gutting. Because the hands are often wet for prolonged periods, infection of injuries is common and a number of unusual or sea-specific pathogens may be present. Fishhooks readily penetrate the skin and, because they are on lines, can reach most parts of the body.
A number of sea creatures have defensive spines, and these can cause penetrating injuries. Some inject venom and this can lead to local or generalised toxic reactions. More information on dangerous aquatic organisms can be found in Ch xxx.
The postures adopted to perform tasks and maintain stability on small fishing vessels can lead to acute or long-term musculoskeletal injury.
Diving accidents in crew doing ship inspections
Diving to inspect and maintain a ship may be undertaken by a specialist contractor or by a crewmember who has, often limited, training and skills as a diver. Common tasks include freeing debris from rudders and propellers and inspecting for damage after grounding or collision. In addition to the normal risk from diving, there are particular risks that arise from being adjacent to a ship, especially in adverse weather conditions. Sea movements may result in rapid changes in position leading to harm from contact with the ship, potentially rapid pressure changes, disorientation and severe lacerations from the propellers from the boat used for diving or from other vessels. Crush injuries may also occur when diving between vessels or between the vessel and a fixed jetty or quay. More information on diving is available in Ch xxx.
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