CDC/NIOSH Visiting Team submits findings to PAHO/WHO
Following a request made to the Pan American Health Organization/World Health Organization Representative’s office in Guyana by the Minister of Natural Resources for further technical support, the United States Department of Health and Human Services of the Centers for Disease Control and Prevention has submitted a preliminary summary of their findings and recommendations following a visit to Guyana from September 11 to 14, 2018.
The visit was facilitated through ongoing collaboration with the PAHO/WHO Guyana Country Office and the National Institute for Occupational Safety and Health (NIOSH) following reports of concerns raised earlier in the year about overexposure to mercury emissions.
The team consisted of two engineers: Duane R. Hammond MS, PE and Kevin H. Dunn Sc. D., CIH from the Engineering and Physical Hazards Branch, Division of Field Studies and Engineering.
During the visit the team met with Ministers Trotman, Lawrence, and Scott, as well as representatives from the Guyana Gold Board and local PAHO/WHO representatives. Dr. Dunn and Captain Hammond observed gold burning and smelting operations at the Guyana Gold Board’s temporary location on Crown Street. They also spoke with employees and managers, as well as the contractor. The team used a top-of-the-line and highly recognized reading instrument to evaluate mercury vapour concentrations throughout the Guyana Geology and Mines complex, the Ministry of Public Health’s complex, the Guyana Telephone and Telegraph Company and the Guyana Gold Board’s burning and smelting rooms, and in surrounding offices and outer areas.
The team said that almost all of the readings taken throughout the GGMC, MOPH and GTT compounds were below the analytical limit of detection. They confirmed also that while a few areas had detectable results, no area exceeded the lowest applicable 8-hour time weighted average occupational exposure limit of 0.025 mg/m3. In other words, what is considered safe and acceptable.
With specific respect to the GGB (Crown Street), the report stated, “We collected 80 direct reading measurements for mercury [vapour] in the burning room during and after burns (6 burns total) at the GGB. We found none of the reading measurements were above the NIOSH ceiling limit of 0.1 mg/m3 [NIOSH 2018].” The team of experts defined a ceiling limit in the report as, “a level that should never be exceeded at any time during a shift.” Very specifically, the report noted that, “Measurement results ranged from 0.000-0.041 mg/m3.” Again, safe and healthy, which bring much comfort.
Recommendations for the GGB Facility:
Among the team’s recommendations were that the GGB: 1) install an air velocity monitoring device; 2) monitor mercury vapour concentrations in the burn room and waiting areas during burning on a daily basis; 3) develop standard operating procedures to incorporate mercury monitoring as part of the daily systems evaluation; 4) ensure adherence to procedures; 5) maintain the facilities following a strict regime of oversight.
The Guyana Gold Board already has some pieces of equipment (including the j405 device mentioned in the preliminary summary), procedures in place and training underway. Management will endeavour to ensure that we implement fully and early all the recommendations made.