Post a comment on the text below

River water downstream of cities and towns in Moldova was significantly more polluted than that upstream. Upstream of cities, ammonium concentrations have decreased steadily since 1992, although less in recent years, while the concentrations downstream have increased. This trend can be attributed to non-treated effluent from the cities. The up-downstream difference is less for BOD. Here the downstream level has decreased in recent years, approaching that of the upstream level.