Textbook of Maritime Medicine

Occupational health in shipping industry covers a greater part of precautionary measures of the health care for seafarers. The seafarer’s profession has been regarded as one of the most dangerous jobs, and people who spend their active lives at sea have been exposed to serious risks which endanger their health and their lives. Although the analyses of seafarers’ morbidity with infectious diseases in recent 20 years have shown a significant fall (from 9, 2 to 3, 2 %), the other factors influencing seafarers’ health cause a significant mortality, both among the seafarers at sea as well as those on land, shortening their life expectancy. The studies of the seafarers’ health status constantly show high rates of mortality, injuries and illness in comparison with similar data of workmen on land, which include incidence of mortality to ten times greater than in other workmen.

A completely exceptional situation where a worker spends his active life in environment which presents both his home and working place for long periods of time, puts them into a completely different situation in comparison with working population on land. Their working place significantly influences their health, so that work in shifts on board and impacts of the working environment like chemical agents, biological agents, closed spaces, physical impacts of electric power, injuries, noise, vibrations, radiations, microclimate and macroclimate conditions or violence at working place present just some of them. The seamen on vessels are additionally exposed to the influence of sea environment such as difficult weather conditions, solar radiation, moving over the unstable surfaces, separation from the families, dangerous working tasks, insufficient sanitary conditions, closed spaces and distant destinations.

Such a situation is additionally influenced by insufficient programmes of health care, excessive use of alcohol and tobacco, non use of personal protective agents and inexistence of safety procedures which are ingrained at working places on land. By introducing computerization and automation, the hard physical work has been minimized, but at the same time, mental pressure at working places has dramatically increased.

Health risks due to exposure to conditions of work and life environment, and health requirements for performing jobs and working tasks related to life and work on board, depend on type of the vessel and area of navigation, on specificity of services and practices on board, on type of operations, on specificity of alliance of ship-owners, correspondents and workmen.

Factors influencing seamen's' work strain: the size of ship increases - average load capacity of a ship in 1961 was 75 000 DWT, and today it makes 200 000 DWT and more; number of crew members decreases - because of continually increasing automation - which is especially visible in engine service - 20 years ago crews were composed of 40 people, while modern ships are managed by only a dozen; applying of satellite communication and navigation in international maritime traffic becomes unavoidable, so there is an increased requirement for obtaining new knowledge and professional training, for compatibility of signalization instruments, as well as an additional requirement for perceptive and psycho-technical abilities, additional visual and hearing requirements and efforts of seamen; a need of long-lasting maintenance of attention to be bale to notice rare occurrences; there is increased usage of computer technology - which leads to increased requirement for computer knowledge of the officers and additional strain of organism by work on video-terminals; the navigation becomes faster - there is a greater exposure to climate changes and faster passing through time-zones, work in shifts is unavoidable because of smaller number of crew members, the number of shifts increases which influences to psychophysical and neuro-vegetative balance and biological rhythms; the ships are rarely in parent port, so the load and discharge of seamen occurs on a great distance from the place of residence; the time of holding of a ship in a port is shorter because of faster loading and discharge of cargo - deck service is more mentally loaded during entrance and leaving a port, as well as during loading and discharging, while engine service is more loaded during navigation, as the possibility of going out to town is reduced because of short staying in a port, especially as discharging is often performed on terminals distant from parent town.

Duties on board (active work) are assigned in a way which is not coordinated with biological rhythm – that problem is more expressed then in workmen on land, no matter if they work in shifts or not. During the whole voyage, the crew is exposed to harmful environmental factors (no matter if they are on duty or resting).

11.1.1   Health hazards on ships

• Dangers from living environment: maritime accidents, falling into the water, plunging, drowning and hypothermia
• Mechanical dangers: unprotected, unsafe or uncontrolled cargos or objects and their parts which hit, squeeze, break or trip. They can be mechanized (forklift truck) or simple (doors on hinges). Winches, pumps, ventilators, shafts, compressors, propellers, hatches, doors, derricks, cranes, ropes, passages and lines for anchor chains, moving cargo; falls: slipping off, stumbling or falls as causes of mechanical injuries - steep ladders, deep ship holds, missing of rails, narrow passages, elevated platforms.
• Dangers from electric power: static (battery) or active (generators) sources of electricity, system of distribution (wiring) and running devices (engines), physical injury caused by electricity - unprotected and ungrounded electric engines (pumps, ventilators), defoliated electric wires, navigational and communicational electronic.
• Thermal dangers: injuries caused by heat or coldness - power lines, refrigeration plants, exhaust pipes, exposure to warm or cold weather on deck.
• Noise: various hearing and other physiological problems because of excessive or long-lasting excessive noise - mechanical noise - engine room: turbo-blowing pipes, diesel engines, especially fast-running turbo-generators, reducers; auxiliary lightning machines, hydrodynamic noise: pumps, propellers, shafts; aerodynamic noise: compressors, boilers, exhaust muzzles and pipes, ventilators, ventilating pipes, ventilation and air-condition muzzles, air-conditioners; electromagnetic noise: electronic devices, radar transformers, other navigational devices.
• Chemical dangers: acute or chronic disease or injury caused by exposure to organic or inorganic chemicals and heavy metals which can be cargo or means for cooling or putting off fire, debugging, and co-product of technological process: inhalation of toxic substances - carbon dioxide (putting off fire, fermentation of warehoused grains, mean for cooling), carbon monoxide (putting off fire, product of explosion, fuel burn of diesel engine), gases from refrigeration systems (ammonium, halogen hydrocarbons - methyl-chloride, freons, carbon dioxide), gases from the cargo in refrigeration plants (carbon dioxide, carbon monoxide, ammonium, hydrogen sulphide, hydrogen - rotting of fruit, vegetables, meat) when failure of the refrigeration plant occurs, especially if the floors are flooded by water, hydrogen (cooling systems), hydrogen cyanide (fumigation of ships), nitrogenous gases (fermentation of warehoused grains, welding), means for chemical cleaning (trichloroethylene), organic solvents, oil derivates, engine oil; skin and eye damage - means for disinfection (phenols, cresols), means for toilet cleaning (sodium hypochlorite); the least common way of poisoning is ingestion of toxic substances - strong acids and bases and other corrosives - means for disinfection (phenols, cresols), organic solvents, hydrogen cyanide, oil derivates, lead, arsenic, engine oil, toxic mushrooms, drugs (barbiturates, diazepam, acetylsalicylic acid, paracetamol)  - usually occurs by mistake, or deliberately, rarely by long-term exposure during the work or because of regular technologic process or the incidents in technologic process; chemical substances are dangerous because of the explosiveness, inflammability and corrosiveness.
• Sanitary dangers: diseases connected with unsafe water, bad hygiene of food or inadequate waste dump; biological dangers: disease caused by exposure to living organisms or their products. Grain dust, raw wood products, cotton bales, bulk fruit or meat, fruits of the sea, agents of infective diseases.
• Radiation dangers: damages by non-ionizing radiation. Intensive exposure to the sun, electric arc welding, radars and communication microwaves.
• Violation: interpersonal conflicts and violation, attack, murder, rough physical fight among the crew. Work in narrow spaces: toxic or non-toxic injury while entering into closed spaces, with restricted enter - cargo holds, ballast tanks, cramped spaces, fuel reservoirs, heaters, warehouses, refrigeration plants.
• Physical work: health problems caused by excessive, inadequate or un-adapted performing of physical work.  Stirring of ice in holds for fish, moving of bulky cargo in closed spaces.

Monitoring of seafarers’ health has been run and established on international level. Although the working conditions of seafarers have been improved, present studies indisputably show that harmful influences of working environment and way of life to seafarers’ health have still been present, and some new consequences of the exposure to that specific working place have become visible. Although all the international recommendations claim that a physician who examines and assesses a seafarer has to be acknowledged with work on board, to be able to protect a seafarer in a right way, not assessing him by parameters which are valid for workmen on land, but in reality it does not work that way. In the ILO/IMO publication from November, 1997, besides that requirement for knowing of the working place, it was especially emphasized that “monitoring of seafarers’ health should be conducted together with other means which include monitoring of working place and working environment” (WHO/ILO. Technical and ethical guidelines for workers’ health surveillance, Geneva, 1997:2).