Nearly all of the recent tests conducted at the Guyana Gold Board (GGB), the Guyana Geology and Mines Commission (GGMC), the Ministry of Public Health (MoPH) and the Guyana Telephone and Telegraph Company (GTT) have found the mercury vapour concentration to be below the analytical limit of detection, according to preliminary results from a visiting inspection team.
A team from the National Institute for Occupational Safety and Health (NIOSH) of the United States’ Centers for Disease Control and Prevention (CDC) visited and conducted the assessments from September 11th to September 14th.
It was the second visit by an NIOSH team.
Based on a request by the government for assistance from PAHO/WHO, after GGMC workers refused to continue to attend work at its Brickdam offices due to fears of overexposure to mercury emissions from the GGB laboratory that was then located in the compound, a team from the NIOSH conducted previous assessments.
In a statement issued on Monday, the GGB said the second team had submitted its preliminary findings and found 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,” the GGB explained.
In addition to the GGMC and Gold Board, there had been concerns raised about mercury vapour emissions affecting workers at the nearby MoPH and GTT offices at Brickdam.
With specific respect to the GGB facility at Crown Street, Queenstown, the team’s 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 0.000-0.41 mg/m3.”
“Again, safe and healthy, which bring much comfort,” the GGB added.
The preceding NIOSH inspection had reported measurements for mercury vapour above the NIOSH ceiling limit of 0.1 mg/m³ in two areas at the interim facility at Crown Street that is being used by the GGB for burning gold. “A ceiling limit is a level that should never be exceeded at any time during a shift. Our results also show that workers in these locations could be overexposed if the mercury vapour concentration remained at these levels for the full shift,” it had said, while highlighting the levels in the waiting room, and the smelting room. It was noted that the measurements for the smelting room were taken while smelting was not underway and the fume hood was not turned on.
With respect to recommendations for the GGB facility, the statement pointed out that among the second team’s recommendations were that the Gold Board install an air velocity monitoring device and monitor mercury vapour concentrations in the burn room and waiting areas during burning on a daily basis.
The statement also noted that the team recommended that standard operating procedures to incorporate mercury monitoring as part of the daily systems should be developed as well as ensuring adherence to procedures and the maintenance of 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,” the statement added.
During the visit, the team observed gold burning and smelting operations at the Guyana Gold Board’s temporary location on Crown Street. The members also spoke with employees and managers, as well as the contractor. It was noted that the team used a top-of-the-line and highly recognised reading instrument to evaluate mercury vapour concentrations throughout the GGMC, MoPH, GTT and GGB offices and outer areas.
