As some work is carried out outside, workers are exposed to bad weather and changes in temperature. There are also heat sources (welding, grinding) that are used in poorly ventilated areas, which increases the temperature. There is little scientific data concerning risks in this population.
Noise exposure is one of the major occupational risks to which workers are exposed, particularly those involved in repair. The source of noise may be machines used as tools for cutting wood (120 dB peak noise) (1), or machine tools, impact (hammering, cutting and falling sheet metal), grinding and associated activities (engine room machinery, welding, and grinding in resonant spaces). In studies of workers in a shipyard, peak noise exposure was recorded as 135 dB from falling sheet metal, 111 dB for grinding, 117 dB for planing and hammering and exposure averaged over 8-hours was 93 dBA for a boilermaker and 94 dBA for a pipefitter. Ships’ energy requirements mean that their engines have to be maintained in port. Noise exposure ranges from 90 to 108 dB, as measured by Andro (6). (See x.y.z[jc1] ) and I will therefore not explore this issue further (7, 8). The only thing to add is that for the population of workers that we are examining here, there is an aggravating factor. Many such workers are exposed to aromatic solvents such as toluene, xylene and styrene. It has been shown in the industry that these solvents are ototoxic and can, via cell toxicity, increase noise-linked hearing loss (9). The recent study by Triebig involving 248 shipyard workers who had been exposed to styrene showed that chronic intense exposure above regulatory limits (> 50 ppm) led to an increased risk of hearing loss (10).
Musculoskeletal problems, either acute or chronic, are frequent causes of time off work and declared occupational diseases in this population group. Use of vibrating tools (grinders, scurfers, turners) exposes workers to the risk of harm to the hands and upper limbs. In a study of 114 construction workers using tools vibrating at 6.32 and 13.39 m/s2 respectively, mean use of 4.64 hours per day was investigated, and the period to onset of Raynaud’s disease was half as long as that given in the ISO 5349 PARK standard (11). This severe impact on the hands was confirmed by findings of reduced nerve conduction velocity in the wrist, hands and fingers in a population of workers in an American shipyard (12) and by the positive correlation between rates of vascular symptoms in the hand and the intensity of exposure to vibration via tools in 214 subjects (13). Tendinopathies in the shoulders (18% of welders in one shipyard) (14) and elbows are also linked to such exposure. Handling and staying in cramped positions for long periods are common in some types of welding and sheet metal jobs. A full welding kit can weigh over 30 kilos, and the nozzle can weigh 2.5 kilos. Electromyography tests on welders show heavy strain on the trapezium, deltoid and finger flexor muscles (15). Effects on the lumbar muscles have also been observed. The risk of lower back pain in welders working in shipyards was confirmed in the study by Axelopoulos concerning 853 workers in a shipyard (16). Over a year, 14% of workers took time off work because of lower back pain, and welders had the highest rate of absence at 18.3%. The recurrence rate reached 41% over the year, and was greater for those who had spinal disc herniation and reduced when working conditions were altered (in favour of workshop work or limiting handling). This confirmed the considerable ergonomic constraints to which workers on board ships are subjected, particularly welders, pipefitters and sheet metal workers. For engineers, the most risky aspects of work is handling, with equipment weighing tens or over a hundred kilos (stern post) that must be manipulated within confined spaces and with little leverage assistance, apart from hoists.
As Brigham (1985) pointed out in his article concerning health in shipbuilding and repair, the risk of ophthalmological disease is the dominant risk (1). These can be divided into two main categories: foreign bodies in the eye, and diseases related to UV and IR exposure. Grinding work is primarily responsible for exposure to the risk of foreign bodies in the eye. Acute corneal lesions, keratitis and secondary effects in the form of traumatic cataracts and ocular siderosis can arise as a result of foreign body exposure (17). Such accidents represented 27% of all occupational accidents in ship repair in 2007, and 18.8% in 2008 (2). Welding is the main activity that causes UV exposure, with the risk of arc eye and ocular melanoma (18) and keratoconjunctivitis photoelectrica, known as “arc eye” (19).