Enrichment and distribution of metals in surface sediments of the Thanh Hoa coastal area, Viet Nam

Spatial distribution of trace elements in coastal sediments of Ha Tinh province, Vietnam

“…The average Cu concentration in the coastal sediments of Ha Tinh province was 10.51 ± 6.30 mg/kg, similar to that in Ha Long bay (14.53 ± 6.30 mg/kg) [14], Tien Yen gulf [15], sedimentary basin of the Red river, Central Vietnamese shelf and slope and Nam Kon Son basin area [16]. Cu concentration was 3-5 times lower than in the coastal sediments of Thanh Hoa province [17] and Cam estuary [18] (Table 3). Pb concentration in the coastal sediments of Ha Tinh province varied in an extensive range from 4.95-25.18 mg/kg, with a mean of 10.51 ± 6.3 mg/kg (Table 1).…”

“…Pb concentration markedly decreased in the deeper sediment layers (Table 2). Compared with other coastal regions in Vietnam, Pb concentration had a similar range with Ha Long bay [14], Tien Yen gulf [15], the sedimentary basin of the Red river, the Central Vietnamese shelf and slope, and Nam Kon Son basin area [16], but was 6-9 times lower than in the coastal sediments in Thanh Hoa province [17] and Cam estuary [18] (Table 3). Zn concentration ranged from 7.1-86.1 mg/kg, averaging 40.99 ± 21.29 mg/kg (Table 1).…”

“…Zn concentration markedly decreased with the depth of sediment layers and from the coastal to the nearshore area (Table 2, Figure 3c). The mean concentration of Zn was approximately that in Ha Long bay [14], Tien Yen gulf [15], the sedimentary basin of the Red river, the Central Vietnamese shelf and slope, and the Nam Kon Son basin area [16], but was 3-5 times lower than coastal sediments in Thanh Hoa province [17] and Cam estuary [18]. The similar concentration of Cu, Pb, and Zn in sediments from the present study with those in sediments from other coastal areas referred that the human activities in coastal areas did not highly impact the marine sediments in Ha Tinh province.…”

“…Mn concentration tended to decrease with the depth of sediment cores (Table 2). Mn concentration was two times higher than that in Tien Yen gulf [15] but lower than that in Ha Long bay [14], the sedimentary basin of the Red river, Central Vietnamese shelf and slope, and Nam Kon Son basin area [16], and the coastal area of Thanh Hoa province [17] and Cam estuary [18] (Table 3). Results showed that this study's higher Mn concentration in the coastal sediments could relate to steel production because manganese phosphate is commonly used to treat rust and prevent corrosion on steel.…”

Assessment of the distribution and ecological risks of heavy metals in coastal sediments in Vietnam’s Mong Cai area

“…Compared with the Red River estuary (Tue et al, 2011), the Thanh Hoa coastal area(Nhon et al, 2021), the Cai estuary(Koukina et al, 2017), and the Dong Nai River (Costa-Böddeker et al, 2017) receive large river in ux and bring much material from the continent to the sea. The heavy metals in the Mong Cai area are lower than in these areas above, not only those supplied by rivers but also from industrial zones in coastal provinces, such as Thai Binh, Nam Dinh at the Red River estuary, Thanh Hoa at the Hoi estuary, Nha Trang at the Cai River estuary, Ho Chi Minh City, and Bien Hoa province at the Dong Nai estuary, where industrial development has recently accelerated signi cantly (Table…”