Occupational exposure to mercury among workers in a fluorescent lamp factory, Quisna Industrial Zone, Egypt

Abstract

Background: With the fast growth in the market of fluorescent lamps, particularly compact fluorescent light, the associated risk of mercury exposure, which is an essential component in all types of fluorescent lamps, has received increasing public attention worldwide. Even low doses of mercury are toxic.

Objective: To study the health consequences of occupational exposure to mercury in workers of a fluorescent lamp factory.

Methods: In a cross-sectional study 138 workers of a fluorescent lamp factory and 151 people who had no occupational exposure to mercury (the comparison group) were studied. Environmental study of mercury and noise levels was done. For all participants a neurobehavioral test battery was administered, spirometry was performed and air conduction audiometry was done. Urinary mercury level was also measured for all participants.

Results: Prominent symptoms among workers exposed to mercury included tremors, emotional lability, memory changes, neuromuscular changes, and performance deficits in tests of cognitive function. Among the exposed group, the mean urinary mercury level was significantly higher in those who had personality changes or had manifestations of mercury toxicity. With increasing duration of employment and urinary mercury level, the performance of participants in neurobehavioral test battery and spirometric parameters deteriorated.

Conclusion: Neurobehavioral test battery must be used for studying subclinical central nervous system dysfunction in those with chronic exposure to mercury. The test is especially useful for evaluating the severity of mercury effects in epidemiological studies. This study also reinforces the need for effective preventive programs for fluorescent lamp industry workplaces especially in developing countries with the lowest unhygienic work conditions.