TY - JOUR
T1 - Spatiotemporal evaluation of water quality and risk assessment of heavy metals in the northern Caspian Sea bounded by Kazakhstan
AU - Ramazanova, Elmira
AU - Bahetnur, Yingkar
AU - Yessenbayeva, Kadisha
AU - Lee, Seung Hwan
AU - Lee, Woojin
N1 - Funding Information:
The research has been supported by the Nazarbayev University Research Grants (Contract No. 021220FD1051 and 091019CRP2106 ). The authors would like to thank a Republican State Enterprise, “Kazhydromet,” which kindly provided the Caspian Seawater data.
Publisher Copyright:
© 2022 The Authors
PY - 2022/8
Y1 - 2022/8
N2 - The water quality of the northern Caspian Sea has not been well-known, and its contamination can adversely affect the health of swimmers and seashore residents. The study sought to determine the contamination state of the Caspian Sea in Kazakhstan and quantify human health risks coming from the existing heavy metals concentration. The Caspian Sea was found to be “fairly to marginally” contaminated (24 < CCME-WQI < 64), with Cd influencing the index significantly. Concentrations of Cd and Pb increase over time (seasonal Kendall test, p-values = 2–4 %) in sites near oil fields and ports, suggesting the significant role of anthropogenic sources in causing diverse pollution events. Pb demonstrated the highest variability and number of outliers (4.3 % of all samples with coefficients of variation reaching up to 175 %). The principal component analysis further revealed that various discharges from oilfields and upstream transport could contribute to the contamination by heavy metals and their concentrations. Contamination is associated with up to 6 % cancer risk for adults. The long exposure duration of swimmers in water increases risks by up to 18 %, indicating the local population is at a higher risk. In conclusion, statistical tests and analysis indicate the presence of anthropogenic sources, and risk assessment reveals swimming can contribute to cancer risk.
AB - The water quality of the northern Caspian Sea has not been well-known, and its contamination can adversely affect the health of swimmers and seashore residents. The study sought to determine the contamination state of the Caspian Sea in Kazakhstan and quantify human health risks coming from the existing heavy metals concentration. The Caspian Sea was found to be “fairly to marginally” contaminated (24 < CCME-WQI < 64), with Cd influencing the index significantly. Concentrations of Cd and Pb increase over time (seasonal Kendall test, p-values = 2–4 %) in sites near oil fields and ports, suggesting the significant role of anthropogenic sources in causing diverse pollution events. Pb demonstrated the highest variability and number of outliers (4.3 % of all samples with coefficients of variation reaching up to 175 %). The principal component analysis further revealed that various discharges from oilfields and upstream transport could contribute to the contamination by heavy metals and their concentrations. Contamination is associated with up to 6 % cancer risk for adults. The long exposure duration of swimmers in water increases risks by up to 18 %, indicating the local population is at a higher risk. In conclusion, statistical tests and analysis indicate the presence of anthropogenic sources, and risk assessment reveals swimming can contribute to cancer risk.
KW - Central Asia
KW - Exposure
KW - Human health risk
KW - Surface water contamination
KW - Swimming
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U2 - 10.1016/j.marpolbul.2022.113879
DO - 10.1016/j.marpolbul.2022.113879
M3 - Article
C2 - 35780631
AN - SCOPUS:85133277754
SN - 0025-326X
VL - 181
JO - Marine Pollution Bulletin
JF - Marine Pollution Bulletin
M1 - 113879
ER -