A high concentration of heavy metals was detected in the environment and in the organisms of Qaraberd settlement residents in Lori Region, Armenia. Qaraberd gold mine is operated in Qaraberd Village.
Experts of Czech "Arnica" NGO took test samples from the soil, surface water and places of mining waste deposits in Qaraberd area in 2022 within the framework of "Participation of civil society in the protection of chemical safety in Armenia" project.
Project coordinator Valeriya Grechko from "Arnica" organization presented the findings of the research.
Arsenic Levels:
Karaberd area classified as moderately to strongly polluted by arsenic.
Arsenic concentrations in soil samples exceed the global average (<0.1 to 67 mg/kg). Arsenic concentrations in the soil samples were within this range, but most of the samples showed concentrations noticeably higher than the world average.
Arsenic concentrations in the sediment samples comply with the Canadian Threshold Effect Level except for one sample (KARAB-SED-02/22) with concentration of 172 mg/kg DW, which does not comply with the Canadian Probable Effect Level either.
Cadmium Levels:
The concentrations of cadmium in three soil samples exceed the US EPA pollution limit for industrial areas, with the highest concentration of 2.2 mg/kg DW found in the soil sample KARAB-SOIL-01/22 that was collected close to the gold mine. Cadmium concentrations in sediment samples were below the limit of quantification except for the sample KARAB-SED-02/22 that was collected from a road flooded by gold-mine drainage. This sample with concentration of 30.2 mg/kg DW exceeds the Canadian Probable Effect Level for cadmium.
Chromium Levels:
Soil chromium concentrations (30.3 mg/kg DW) lower than global averages (60 mg/kg) but any of the samples does not meet the Armenian soil standard for chromium.
Sediment samples comply with the Canadian Threshold Effect Level for chromium.
Copper Levels:
The mean concentration of copper in the soil samples (78.4 mg/kg DW) is in the range of different soil groups (14 - 109 mg/kg). All seven soil samples exceed the Armenian soil standard, but any of the soil samples does not exceed the US EPA pollution limit for residential areas.Copper concentrations in four of the seven sediment samples exceed the Canadian Threshold Effect Level. High concentrations of copper are present in sediment samples from drainage of the gold mine and from the Pambak River downstream of the mine, while the copper concentrations in sediment samples collected upstream of the goldmine are lower. In addition, a high concentration of copper (402 mg/kg DW) was also found in the mining waste sample. These findings indicate that the gold mine could be a source of copper pollution to the drainage water.
Iron Levels:
Soil iron concentrations below the global average (35,000 mg/kg) but exceed US EPA pollution limits for residential areas.
Sediment sample (KARAB-SED-02/22) from a mine tunnel flooded by gold mine drainage contains exceptionally high iron concentration (114,000 mg/kg DW).
Mercury, Molybdenum, Nickel, Lead, and Vanadium Levels:
Low mercury concentrations in sediment samples, except one (KARAB-SED-02/22) indicating a potential pollution source from mining (0.802 mg/kg DW).
Molybdenum concentrations in soil samples higher than global averages (1.1 mg/kg) but comply with US EPA limits.
The levels of nickel in all eight soil samples exceed the Armenian soil standard, but any of them does not exceeds the US EPA pollution limit for residential areas. The sediment sample KARAB-SED-02/22 collected from a road flooded by gold mine drainage contains a high nickel concentration of 33 mg/kg DW.
Lead concentrations in 3 soil samples exceed the world average (27 mg/kg DW) but comply with US EPA limits. High lead concentrations are found in two soil samples that were collected close to the gold mine (KARAB-SOIL-01/22 a KARAB-SOIL-02/22) and in one sample from a private garden.
Vanadium concentrations in all soil samples below the world average (129 mg/kg) but exceed US EPA limits.
Zinc Levels:
High concentration of zinc is found in the sediment sample KARAB-SED-02/22 that was collected from a road flooded by drainage of the gold mine. This sediment sample with concentration of 17 600 mg/kg DW does not comply with Canadian Probable Effect Level.
Biological Samples:
In Karaberd, urine and hair samples were collected from a cohort of nine women (aged 46 to 83), five men (aged 49 to 83), and hair samples from four women (aged 59 to 83) to assess heavy metal exposure.
Arsenic Levels:
Arsenic concentrations in urine samples exceeded the limit of quantification (LOQ) for all participants.
Mean urine arsenic levels were comparable between genders (12 µg/g creatinine for women, 12.51 µg/g creatinine for men).
The 95th percentile for urine arsenic was twice as high in men compared to women (35.6 µg/g creatinine vs 16 µg/g creatinine).
Arsenic concentrations in hair samples from women ranged between 0.03 and 0.07 mg/kg, indicating moderate exposures to arsenic in the senior population tested in the area.
Lead Levels:
Urine lead levels were above LOQ in all tested samples, with higher mean levels in women compared to men (2 µg/g creatinine vs 1.15 µg/g creatinine).
Mean hair lead concentration for women was 0.28 mg/kg (95th percentile 0.56 mg/kg), below levels of concern and general lead-unexposed populations
Cadmium Levels:
In Karaberd, all urine and hair female samples and 80% of male urine samples tested for cadmium above LOQ.
Geometric mean of male cadmium urine levels (0.65 µg/g creatinine) ranked higher than reported in other Armenian cohorts.
Female cadmium urine levels (mean 0.45 µg/g creatinine) were within the range observed in other regions.
Mean cadmium concentration in female hair was 0.189 mg/kg, indicating moderate exposure.
In Karaberd, cadmium urinary concentrations in both genders warrant further investigation into the possible source or sources of pollution and clinical symptoms.
Mercury and Copper Levels:
Hair mercury was detected in all samples, with levels of concern (mean 0.059 mg/kg, 95th percentile 0.142 mg/kg).
Copper was present in all hair samples (mean 9.41 mg/kg, 95th percentile 13.04 mg/kg), within normal ranges.
Urinary copper levels were considerably higher in females than males (mean 60.4 vs 17.3 µg Cu/g creatinine), warranting further assessment.
Mercury Levels:
Hair mercury was detected in all four samples, ranging from 0.02 to 0.147 mg/kg.
Mean hair mercury was 0.059 mg/kg, with a 95th percentile of 0.142 mg/kg.
Copper Levels:
Hair copper mean concentration was 9.41 mg/kg, 95th percentile 13.04 mg/kg.
Urinary copper levels were considerably higher in women compared to men (mean 60.4 µg/g creatinine vs 17.3 µg/g creatinine).
Nickel, Molybdenum, and Chromium Levels:
Urinary nickel levels were detected in all samples, with a mean of 3.66 µg/g creatinine for women and 3.47 µg/g creatinine for men, that is at levels that represent a higher concern compared to the general U.S. population and our previous studies in Armenia.
Molybdenum was detected in a single sample in the Karaberd cohort at 0.05 mg Mo/kg hair, the trace metal therefore portends low concern in this area. Chromium was not tested in the Karaberd hair samples.
January 08, 2024 at 11:58