Concentrations of 238U, 234U, 226Ra, 210Pb, and 210Po in seawater at Thanh Hoa coastal area, Vietnam

Thanh Hoa Coastal was known for many titanium placers and key economic of the estuary area. 238U, 234U, 226Ra, 210Pb, and 210Po average activities in different sampling stations and depths of seawater at this coast showed 0.77, 0.78, 9.09, 49.8, and 54.3 mBq L−1, respectively. The result showed disequilibrium between 210Po and 210Pb and different 210Po/210Pb ratios by depth. The high 226Ra, 234U, and 238U activities could relate to titanium placers along coastal and river sediment sources. There was a relation between 226Ra and 210Pb activities with sampling depth, distance from shore, while it was insignificantly recorded for 210Po, 234U, and 238U.