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Mercury is still used in developing countries to extract gold from the ore in small-scale gold mining areas. This is a major health hazard for people living in mining areas. The concentration of mercury in urine was analysed in different mining areas in Zimbabwe, Indonesia and Tanzania. First the urine samples were analysed by CV-AAS (cold vapour atomic absorption spectrometry) during the field projects with a mobile mercury analyser (Lumex(®) or Seefelder(®)) and secondly, in a laboratory with a stationary CV-AAS mercury analyser (PerkinElmer(®)). Caused by the different systems (reduction agent either SnCl(2) (Lumex(®) or Seefelder(®))) or NaBH(4) (PerkinElmer(®)), with the mobile analysers only the inorganic mercury was obtained and with the stationary system the total mercury concentration was measured. The aims of the study were whether the results obtained in field with the mobile equipments can be compared with the stationary reference method in the laboratory and allow the application of these mobile analysers in screening studies on concerned populations to select those, who are exposed to critical mercury levels. Overall, the concentrations obtained with the two mobile systems were approximately 25% lower than determined with the stationary system. Nevertheless, both mobile systems seem to be very useful for screening of volunteers in field. Moreover, regional staff may be trained on such analysers to perform screening tests by themselves., (Copyright © 2011 Elsevier GmbH. All rights reserved.)

Breast-feeding can be a source of mercury exposure for infants. The main concern up to now is methyl-mercury exposure of women at child-bearing age. Certain fish species have high levels of methyl-mercury leading to consumer's advisory guidelines in regard of fish consumption to protect infants from mercury exposure passing through breast milk. Little is known about the transfer of inorganic mercury passing through breast milk to infants. Epidemiological studies showed negative health effects of inorganic mercury in gold mining areas. Small-scale gold miners use mercury to extract the gold from the ore. Environmental and health assessments of gold mining areas in Indonesia, Tanzania and Zimbabwe showed a high exposure with inorganic mercury in these gold mining areas, and a negative health impact of the exposure to the miners and the communities. This paper reports about the analysis and the results of 46 breast milk samples collected from mercury-exposed mothers. The median level of 1.87mug/l is fairly high compared to other results from literature. Some breast milk samples showed very high levels of mercury (up to 149mug/l). Fourteen of the 46 breast milk samples exceed 4mug/l which is considered to be a "high" level. US EPA recommends a "Reference Dose" of 0.3mug inorganic mercury/kg body weight/day [United States Environmental Protection Agency, 1997. Volume V: Health Effects of Mercury and Mercury Compounds. Study Report EPA-452/R-97-007: US EPA]. Twenty-two of the 46 children from these gold mining areas had a higher calculated total mercury uptake. The highest calculated daily mercury uptake of 127mug exceeds by far the recommended maximum uptake of inorganic mercury. Further systematic research of mercury in breast milk from small-scale gold mining areas is needed to increase the knowledge about the bio-transfer of mercury from mercury vapour-exposed mothers passing through breast milk to the breast-fed infant.

Dental amalgam, which has been used for over 150 years in dental practice, consists of about 50% metallic mercury. Studies on animal and humans show that mercury is continuously released from dental amalgam and absorbed by several body tissues. It is widely accepted that the main source of mercury vapor is dental amalgam and it contributes substantially to mercury load in human body tissues. There is still a controversy about the consequences of this additional mercury exposure from amalgam to human health. Many studies were performed to evaluate possible adverse effects. In this comment, these studies were analyzed with regard to their methodical quality by considering the newest findings on mercury toxicity and metabolism. In sum, a number of studies are methodically flawed drawing inaccurate conclusions as to the safety of dental amalgam.