Risk of high blood pressure in salt workers working near salt milling plants: a cross-sectional and interventional study.

BACKGROUND: Workers working close to salt milling plants may inhale salt particles floating in the air, leading to a rise in plasma sodium, which, in turn, may increase the blood pressure and the risk of hypertension. METHODS: To test the above hypothesis, occupational health check-up camps were organized near salt manufacturing units and all workers were invited for a free health examination. The workers who worked with dry salt in the vicinity of salt milling plants were defined as "non-brine workers," while those working in brine pans located far away from milling plants were defined as "brine workers." Blood pressure (BP) was measured during each clinical examination. In all, 474 non-brine workers and 284 brine workers were studied. RESULTS: Mean systolic blood pressure of non-brine workers (122.1 +/- 13.3 mm Hg) was significantly higher than that of brine workers (118.8 +/- 12.8 mm Hg, p < 0.01). Mean diastolic blood pressure of non-brine workers (71.5 +/- 10.4 mm Hg) was significantly higher than that of brine workers (69.7 +/- 9.4 mm Hg, p = 0.02). The prevalence of hypertension was significantly higher in non-brine workers (12.2%) than in brine workers (7.0%, p = 0.02). Nineteen salt workers were monitored while they used face masks and spectacles, for six days. Systolic, as well as diastolic, blood pressure of these workers began declining on the third day and continued to decline on the fourth day, but remained stationary up to the sixth day. The concentration of salt particles in the breathing zone of these workers was 376 mg/m3 air. CONCLUSION: Inhalation of salt particles in non-brine workers may be an occupational cause of increased blood pressure.

Knowledge, attitude and practices related to occupational health problems among salt workers working in the desert of Rajasthan, India.

Workers in the salt industry are exposed to direct sunlight, salt dust and contact with brine. To assess their awareness, attitude and practices related to occupational health problems, 205 salt workers were interviewed about health hazards and problems related to their working conditions, usage of protective measures and suggestions for their improvisation. The brine workers had a fair knowledge of their occupational health problems (98.7%), protective measures (100.0%) and their benefits (100.0%) as compared to non brine workers for whom these figures were 89.0%, 85.8% and 78.7% respectively. The brine workers (29.5%) and non brine workers (31.5%) used unconventional measures to prevent contact with salty water, salt dust, raw salt and glare. There was a huge gap between their knowledge and practice with protective devices, though they suggested improvements in protective devices to increase their acceptability.

The risk of pterygium in salt workers.

PURPOSE: To find out if exposure to direct and reflected sunlight in brine pans (ground water rich in salt, kept in wide pans in open air for salt manufacturing), increases the risk of pterygium in exposed salt workers. METHODS: It was a cross sectional observational study, in which 865 salt workers were examined in the Free Occupational Health Check-up camps held near salt sites; 304 persons from the same area engaged in other work were examined as controls. The prevalence of pterygium in different age groups was compared between brine workers (who worked in the brine pans), dry salt workers, (who were engaged in the loading, weighing, milling, packing or transportation of the dry salt but never worked in brine pans) and non-salt-worker controls. RESULTS: The prevalence of pterygium was significantly higher in brine workers (21.0%) as compared to dry salt workers (9.1%) (Yates corrected chi(2) = 23.45, p = 0.000001) and non-salt-worker controls (9.4%) (Yates corrected chi(2) = 15.69, p = 0.00007). It increased with age and duration of employment in the salt industry. CONCLUSIONS: Brine workers have a higher risk of developing pterygium probably due to their exposure to sunlight reflected both from the surface of brine and from the surface of salt crystals.