Salt factories take toll on workers' blood pressure

Salt factory workers inhale large amounts of salt particles, and have an increased risk of developing High Blood Pressure as a result, according to a new report.

However, wearing face masks and protective eyewear appears to protect these workers from the effects of salt, the authors note.

This study is the first to demonstrate any occupational hazard associated with table salt. The authors reason that inhaled salt particles may be absorbed into workers' bodies through their lungs, or through the gastrointestinal system, where they are taken up in the bloodstream.

In the journal Environmental Health, Kripa Ram Haldiya of the Desert Medicine Research Centre in Jodhpur, India and colleagues note that most salt milling plants in India are not fully enclosed, and consequently release salt particles into the air.

Salt milling plant workers "may therefore inhale considerable amounts of salt during working hours," the authors note.

To investigate if working near salt plants affects blood pressure, the researchers measured blood pressures of 758 workers, 474 of whom were involved in crushing, grinding, milling, packing and loading salt near salt milling plants.

The investigators found that workers in regular contact with dry salt had significantly higher blood pressures than others. About 12 percent of salt workers also had hypertension, compared with only 7 percent of those who didn't work with dry salt.

As part of the study, Haldiya and colleagues also asked 19 salt workers to wear face masks and protective eye wear for 6 days. They found that after the third day, workers' blood pressures began to decline, suggesting that these precautions can protect workers from the effects of salt.

SOURCE: Environmental Health, July 25, 2005.