The indigenous fisherman divers of Thailand: in-water recompression

BACKGROUND

The Urak Lawoi, part of the Sea Gypsies of Thailand, have been diving using surface-supplied compressed air for more than 30 years. Their dive sites range from one hour to several days from their villages. Similar to other indigenous fisherman divers, the Urak Lawoi suffer from a high incidence of decompression illness. Their methods of in-water recompression were investigated.

METHODS

In December 1998, available divers in two Urak Lawoi villages were asked if they had ever been treated using in-water recompression following decompression illness. If the divers responded positively, a questionnaire-based interview was carried out. Divers were asked to recall the cause of the accident, their diving patterns of the day, the parts of the body affected, the depths and times of in-water recompression and whether the problems were resolved as a direct result of this action.

RESULTS

Eleven divers, aged 19-52, were interviewed. Causal factors listed by the divers included diving pattern 55% (6/11), rapid ascent 27% (3/11), and equipment failure 18% (2/11). Divers were recompressed in water using surface-supplied compressed air. The time between surfacing from the accident-related dive and being put back in the water ranged from immediately to 60 minutes. Depth and duration of in-water recompression ranged from 4 to 30 meters and 5 to 120 minutes. Outcomes reported by the divers were: improved or resolved at depth with no return of symptoms at surface in 64% (7/11), improved or resolved at depth with a return of symptoms at surface in 18 (2/11), and not resolved at depth in 18% (2/11).

DISCUSSION

Health-care workers in the villages may be able to provide basic first aid but, for some villages, a medical doctor may be as much as 10 hours away and a recompression facility as far as 16 hours in good weathier. In-water recompression has, within the diving population, proved to be an appropriate first-aid measure for decompression illness. A future project activity will develop consensus guidelines for determining under what circumstances in-water recompression using surface-supplied air should be carried out and identify appropriate methods that the Urak Lawoi can apply.

The indigenous fisherman divers of Thailand: diving-related mortality and morbidity

The Urak Lawoi are indigenous fishermen on Thailand's west coast. The population includes an estimated 400 divers who dive using surface-supplied compressed air. In a cross-sectional survey conducted among the 6 major communities of Urak Lawoi, questionnaire-based interviews were administered to active divers, ex-divers, and families or colleagues of divers who had died in the previous 5 years. Six deaths resulting from diving-related accidents were identified, indicating a diving-related mortality rate of approximately 300 per 100,000 person-years, while in the same 5-year period 11 divers had been disabled owing to diving-related events, indicating a diving-related disabling event rate of approximately 550 per 100,000 person-years. Among 342 active divers interviewed, one third reported having suffered from decompression illness, although based on reported current symptoms over 50% were classified as suffering from recurring non-disabling decompression illness. Physical examination conducted on a subset of 98 active divers revealed the presence of spinal injury (clonus, raised muscle tone, and heightened reflexes) and of joint damage (pain in one or more joint, crepitus, or restricted movement) in 24 and 30% respectively. Improved primary prevention and medical treatment are needed to reduce mortality and morbidity among this population.

The indigenous fisherman divers of Thailand: diving practices

Diving practices of a group of indigenous people living on Thailand's west coast were investigated. Village chiefs were first interviewed using a questionnaire. Three hundred and forty-two active divers were then interviewed by health care workers using a second questionnaire. Field observation was used to further develop information and confirm diving practices. Divers in 6 villages, whose basic means of making a living is from diving for marine products such as fish and shellfish, have diving patterns that put them at substantial risk of decompression illness. Breathing air from a primitive compressor through approximately 100 m of air hose, these divers have long bottom times coupled with short surface intervals. Forty-six point two percent of the divers indicated that they would not make a stop during ascent from a long deep dive (40 m for 30 min). When comparing their previous day of diving to the U.S. Navy Standard Air Decompression Table (U.S. Navy, 1993), 72.1% exceeded the no-decompression limits set by the tables. Diving patterns point to a need for more in-depth research into the diving patterns of this indigenous group. Future research should include the use of dive logging devices to record depths and times. There is also a need to provide divers with information and training to reinforce positive practices and strengthen knowledge of the risks associated with their current diving practices.

Reference spirometric values for healthy lifetime nonsmokers in Thailand

The normal spirometric reference values for Thai people are still not yet available. The aim of this study was to establish standard spirometric equations for Thai people. Subjects 10 years of age and over were selected and their demographic distributions represented that of the population of the whole country. Inclusion criteria were strictly lifetime nonsmokers, no history of chronic cardiopulmonary disease (using a modified ATS--DLD 78 respiratory adult questionnaire), normal standard chest radiograph and unremarkable physical examination. They had to be without respiratory symptoms at the time of the study. Spirometric values were obtained by 5 turbine system 'Pony graphic' (Cosmed, Italy) spirometers which met ATS recommendations. A normal group of 2299 women and 1655 men were selected. Regression analyses using sex, height and age as independent variables were used to provide equations for predicted values. The results were: [table: see text] FVC and FEV1 from this study are close to the Chinese but are 8-20 per cent lower than the Caucasians. These predicted equations are recommended to be used for future reference values in the Thai population.

Silicosis and pulmonary tuberculosis in stone-grinding factories in Saraburi, Thailand

The stone-grinding industry is well known to place its workforce at higher risk for silicosis. In addition, workers who are exposed to silica fibers are at a higher risk for pulmonary tuberculosis. This study was conducted to determine the prevalence levels of silicosis and pulmonary tuberculosis among workers in 33 factories in 3 subdistricts of Saraburi, Thailand and the associated risk factors. Thirty-one of the factories (93.9%) had amounts of either total dust or respirable dust exceeding threshold limit values with the average levels of total dust and respirable dust of 24.3 +/- 34.6 and 2.4 +/- 1.6 mg/m3 respectively. Radiologic patterns indicated that 61 workers (9.0%) had silicosis and 13 workers (1.9%) had pulmonary tuberculosis. The prevalence of silicosis and pulmonary tuberculosis was significantly associated with years of work. This study demonstrated the need for developing and supporting potential primary preventive intervention, periodic medical screening as a part of a medical surveillance system and a national occupational medical services program.

Experiences of successful action programmes for occupational health, safety, and ergonomics promotion in small scale enterprises in Thailand

Small-scale enterprises are playing a vital role for the national economy in Thailand, creating employment in both urban and rural areas. The improvement of working conditions and occupational safety and health, together with improved productivity has long been a priority. How we could practically provide owners and workers of small-scale enterprises with opportunities for improvement action has been our concern. In the present project, we have adopted a new programme of action which emphasizes participation, a positive approach and locally made solutions. The project site was in Samutprakarn province, an industrial zone near Bangkok. Four local small-scale enterprises participated in the action programme. They were a lead smelting, a dry-cell battery plant, a wet-cell battery plant and a pesticides factory. The programme consisted of the following steps. 1) A demonstration training session was conducted to motivate the enterprises' representatives to take action. Locally invented improvement examples were presented and small group discussion was organized for facilitating their action. 2) The participants were encouraged to use a checklist for assessing safety, health and ergonomic risks in their own workplaces. Concrete action plans were established based on their checklist results. 3) The improvement action started, in which step-by-step approaches were emphasized. Advisory and supporting roles of expert teams comprising the authors and other professionals were important to accelerate and sustain the action at these enterprises. On the basis of this self-help action, the participants were enabled to make many improvements at their workplaces. These improvements developed by their own initiative were multi-factorial. They included 1) machine and electrical safety device, 2) workstation redesign, 3) materials handling improvement, 4) establishing new welfare facilities such as canteens or bathrooms and 5) work environment improvement such as better lighting or enclosure of hazardous substances. Our experiences showed that there was a large potential to initiate local improvement actions and duplicate them in a participatory manner. Of particular importance were the positive attitudes towards self-help workplace action and the focus on locally available solutions.