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785 Occupational exposure to mercury in a small scale gold mining workers and families in handeni, tanzania
  1. Aiwerasia Vera Ngowi,
  2. Elida Wilfred Macha
  1. Muhimbili University of Health and Allied Sciences, Dar-es-Salaam, Tanzania


Introduction Mercury is a highly dangerous neuro-toxicant. High exposures in artisanal gold mining have significant health and environmental impacts. We aimed to determine mercury exposure levels and to assess the health effects among the artisanal gold miners and their families

Methods A cross sectional descriptive study was conducted on 292 miners and their families. Interviews and medical examinations were conducted. A sample of 30 participants with history of mercury use had mercury analysis performed on their hair, urine and blood by Inductively Coupled Plasma Optical Emission Spectrometry. Data analysis was done using Epi-Info.

Result The mean mercury levels in urine and blood were 46.3 µg/L and 14.5 µg/L respectively, with a maximum of 74.7 µg/L for urine and 56.7 µg/L for blood. Out of 21 urine samples, 10 (47.6%) exceeded the maximum World Health Organisation (WHO) acceptable level of 50 µg/L. Out of 25 blood samples, 13 (52%) exceeded the WHO normal range of 5–10 µg/L. All hair samples were below the detection limit of 0.01 ppm. Miners engaged in amalgamation and burning of amalgam had higher mean mercury levels in urine (54 µg/L, p=0.03) and blood (14.3 µg/L, p=0.9) than others. Tremor of the eyelid (30%) was significantly higher (p<0.005) in miners than non-miners. Miners recorded blue line in gums (34%), blue coloured ring in periphery of iris (11%), dysmetria (9%), gingivitis (7%), intention tremor (5%), decreased mental labial reflex (5%), decreased Babinski reflex (5%), ataxia (3%) and decreased ankle jerk reflex (2%). About 50% of participants with clinical signs of mercury intoxication were found to have mercury levels in their blood and urine above WHO standards.

Discussion Our findings show higher levels of mercury in urine, blood and hair above recommended values which correspond to the neurological symptoms. There is a need for interventions on the reduction of the mercury exposure among workers.

  • Occupational Health
  • artisanal mining
  • Handeni

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