Environmental, ecological and human health risk assessment of heavy metals in sediments at Samsun-Tekkeköy, North of Turkey

Abstract

A detailed study was conducted in order to evaluate the effects of heavy metal pollution in the sediments in terms of environmental, ecological and human health. Sediment samples were collected from 5 different points in two seasons, namely summer (August 2017) and winter (December 2017), to determine the distribution of heavy metals, potential pollutants, toxic and ecological risks in the river sediments in Samsun -Tekkeköy district located in the Mid-Black Sea Region of Turkey and to evaluate the human health risk. The distribution of heavy metals at the sampling points was Fe > Al > Mn > Zn > Cu > Cr > Ni > Pb > Cd based on their averages. According to the toxic risk index (TRI) results, sampling point OIZ (Organized Industrial Zone) Channel (T3) was also found to have a moderate risk, and it was determined that the highest contribution was from Cu > Ni > Cd > Cr, respectively. Potential ecological risk (PERI) results revealed a low risk except for Cd metal at all sampling points. While the sediment enrichment factor (EF) did not show much metallization at many points, the highest enrichment was observed in Cd, Cu, and Zn metals and at sampling point T3. According to the geoaccumulation index (I geo ) and contamination factor (C F ), sampling point T3 showed contamination with Cd, Cu, Cr, and Zn. Evaluation of human health risk showed that the hazard index (HI) results of carcinogenic and non-carcinogenic risks were higher among children than adults. The total lifetime cancer risks (TLCR) of heavy metals were within the limits determined by USEPA. However, the risk was ranked as Cr > Cd > Pb. Sediment Quality Guidelines (SQG) and pollution index results showed that heavy metal contamination was due to anthropogenic and industrial activities since the region was an industrial zone. It was determined that heavy metals posed ecological risks and that Samsun-Tekkeköy region was moderately and signi cantly contaminated.

Distribution, source apportionment, and risk analysis of heavy metals in river sediments of the Urmia Lake basin

“…This result implies that the non-carcinogenic risk of diseases caused by the ingestion of all heavy metals from the riverine sediment of the region is much more hazardous than that by dermal contact and inhalation. These observations are analogous to the findings of the studies conducted by Proshad et al 52 and Şimşek et al 2 . The HQ ranking of metals demonstrated the descending order of Pb > Ni > Cd > Cu > Zn for three exposure pathways and both age groups and seasons.…”

“…Moreover, the PLI value was classified as no pollution (PLI < 1), moderate pollution (1 < PLI < 2), high pollution (2 < PLI < 3), and extremely high pollution (PLI > 3) 37 . Pollution and pollution load indices are effective tools to evaluate the magnitude of contaminants in the environment and are commonly used to appraise the status of heavy metals in various ecosystems 2 , 15 , 37 .…”

“…The accumulation of heavy metals in sediments is a major threat to aquatic ecosystems and other components of the natural environment 1 , 2 . Sediments are important sinks and carriers of heavy metals in the land–water transition zone, retaining almost 99% of the adsorbed metals after entry into the aquatic ecosystems 3 , 4 .…”

“…Thus, sediment is a fundamental and dynamic part of the aquatic ecosystems―bearing physical and biogeochemical characteristics that determine the potential environmental risk. The assessment of these traits provides critical information about the significance of heavy metal pollution and guides environmental specialists toward specific remediation strategies 2 , 14 . Likewise, such information will assist governments, policymakers, and environmental activists to gain insight into the relationships between coastal development and its sustainable management to protect shorelines from worldwide heavy metal pollution 15 .…”

“…Urmia Lake, with a surface area of approximately 5200 km 2 is the second largest salt lake in the world 19 . This endorheic saltwater lake presents one of the rarest and most diverse biosphere reserves in Iran and the world 20 .…”