The findings of this study collectively indicate that occupational exposure to mercury, even at low levels, is associated with a significant increase in the prevalence of symptoms of intoxication. Additionally, they provide circumstantial evidence in favour of the notion that the current value of TLV of this metal do not provide sufficient protection against the appearance of neuropsychological symptoms. Finally they may cast doubt on the appropriateness of current value of BEI, per-se, as a sensitive means for biomonitoring of mercury exposed individuals

Masoud Neghab, Alireza Choobineh, Jafar Hassan Zadeh and Ebrahim Ghaderi

Symptoms of Intoxication in Dentists Associated with Exposure to Low Levels of Mercury 
Ind Health 2011; 49 (2): 249-54 

ABSTRACT

The present study examined the effects of occupational exposure of a group of dentists to low levels of mercury. The study population consisted of 106 dentists and 94 general practitioners (referent group), from private and public clinics in Shiraz city. Subjects were requested to complete a questionnaire on demographic variables, suspicious symptoms of intoxication and work practices. Additionally, atmospheric and urinary concentrations of mercury were measured by Atomic Absorption Spectroscopy technique. The data were analysed by χ(2) test, independent sample t-test and multivariate logistic regression analysis, where applicable. Both groups were similar as far as most demographic and socioeconomic variables, but age and number of personal amalgam fillings, were concerned. Median of atmospheric concentration of mercury was found to be 3.35 μg/m(3). Likewise, the urinary concentration of mercury in dentists was estimated to be 3.16 μg/g creatinine. This value was significantly higher than that of the referent group. Similarly, analysis of the data revealed that neuropsychological, muscular, respiratory, cardiovascular and dermal symptoms were more prevalent in dentists. Our findings indicate that occupational exposure of dentists to mercury, even at low levels, is associated with a significant increase in the prevalence of symptoms of intoxication.

(Industrial Health is a scientific journal published by the National Institute of Occupational Safety and Health in Japan.)