Results of sediments and soil samples analyses in Nura region
Martin BystrianskĂ˝ Institute of chemical technology Prague
Focus of the study
• Nura contamination caused by using Hg in former acetaldehyde plant „Karbid“ • Verification of previous remediation, identification of contamination • Monitoring of contamination in surroundings of ash-deposit site and landfill for chemical waste used by the „Karbid“ plant
Target contaminants • Mercury (Hg) – coal burning, chemical industry – high toxicity, affects nervous system, accumulates in biological matter and in sediments – Minamata (Japan) – 1950´s serious poisoning due to disposal of wastewater containing Hg, which accumulated in fish and thus poisoned people
Target contaminants II
• Heavy metals – As, Cd, Cr, Cu, Pb, Zn Toxic for men, animals and plants Accumulating in biomass (fish) and sediments • In some samples: - Pesticides - Polychlorinated biphenyles (PCB) - Polychlorinated dibenzodioxines, dibenzofuranes and dioxine like PCBs • Group of compounds, often carcinogenic
Examinated locality • River Nura sediments and ground on upper stream up to 20 km under Samarkand reservoir • Ground from villages near to Nura river • Chicken eggs from these villages • Ash-deposite site near Temirtau, formerly used by plant Karbid for chemical waste disposal
Examinated locality
Pollution limits • Concentration of pollutants in samples were compared with RSL (Regional Screening Levels) – further exploration or removal of contamination shoul be carried out if RSL are exceeded. • Derived using exposure parameters and factors representing the maximum justifiable chronical exposure – based on the direct contact with target compounds. • RSL are derived from US EPA recommendation (2013)
Levels of pollution limits Compound
CAS number
[mg/kg]
Ground [mg/kg dry matter] Industrial area
Other areas
Hg
7439-97-6
43
10
dioxines TEQ (ng/kg)
1746-01-6
1,8x10-5 18
4,5x10-6 4,5
PCB mixture of congeners
1336-36-3
0,74
0,22
Pb
7439-92-1
800
400
Cd
7440-43-9
800
70
Cu
7440-50-8
41 000
3 100
Cr – total
18540-29-9
5,6
0,29
As
7440-66-6
310 000
23 000
Zn
7440-38-2
2,4
0,61
Chemical analyses results – Nura sediments [mg/kg]
24/1
24/2
24/3
24/4
24/5
24/6
24/7
24/8
Hg
2,17
5,26
2,19
0,69
0,49
0,08
0,05
0,04
dioxines (ng/kg)
0
0
0
0
0
0
0
0
PCB
72,3
24913
38
0
29,3
108,7
25,9
175000
[mg/kg]
24/9
Sed 1
Sed 2
Sed 3
Sed 4
Sed 5 Sed 6
Sed 7
Hg
0,05
10,80
707,8
4,03
85,30
177,7
11,78
10,10
dioxines (ng/kg)
0
2,3
5,2
1,5
0
12
218
5,9
PCB
0
0
0
0
0
0
0
0
Chemical analyses results – heavy metals in Nura sediments compound [mg/kg]
minimum
average
maximum
Pb
5,4
24,5
232
Cd
0
0,10
0,80
Cu
7,8
18,4
38,9
Cr – total
7,7
18,4
40,3
As
22,2
60,4
146
Zn
0
0
0
Chemical analyses results – chemical landfill (ash-disposal site) • 12 ground and sediments samples • Heavy metals did not exceed chosen limits • PCB – detected only in 2 samples, limits were not exceeded
Intumak reservoir • Ministry of Environment of the Republic of Kazkhstan • Elevated levels of Hg in Intumak fish in comparison to Samarkand reservoir fish • Values below Kazakh limits, but exceeded US EPA reference dose (0,22 ppm) • More than 70 km far from the potential source
Conclusions • In some samples higher concentration of mercury and PCB was determined • Hg and PCB are bioaccumulative, by consumption of contamined fish, human health can be damaged • Need of riverbed remediation • Concentration of other toxic compounds did not exceed limits indicating contamination • Soil from villages did not contain Hg or other contaminants • Samples from ash-disposal site did not contain higher concentrations of toxic compounds
• Thank you for your attention Martin Bystrianský, ICT Prague martin.bystriansky@vscht.cz
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