I am the source of the Table 1 mentioned in L. Finegold's letter, and the editors of Eos have asked me to respond.
I don't know about tons of European lead emissions, which was mentioned in the other offending paper, but when it comes to Mississippi and Missouri River discharges, the U.S. Geological Survey (USGS) reports measurements to the nearest integer value in cfs (ft3/s). Converting into metric (cmss; m3/s), the values keep the same number of significant figures. Table 1 in Pinter et al.  reported means and standard deviations of USGS annual maximum discharges. The means retain the same number of significant figures as the least precise value in each discharge set (nearest whole unit in cms), and the standard deviations are reported to the same decimal place as the means (again, nearest whole cms).