The results of studies of an acid-base indicator of the snow cover pH in the Primorskii krai for 2004-2005 are analyzed. Long-term observations of precipitation pH in the Russian Far East region are also considered. The results of studies of the snow cover pH of 2005 differed from the earlier data by the lower values of the acid-base indicator. Synoptic analysis demonstrated that acid precipitation in the Primorskii krai could be due to long-range transboundary pollution transport from Central China. The tendency towards a decrease in the precipitation pH values over most of the Far East region is traced from long-term observations, which under conditions of the general economy recession and population decrease can be attributed to transboundary transport of acid precipitation.

Variability of precipitation components in the Far East of Russia is analyzed using the monitoring of their chemical composition. It is demonstrated that the increase in precipitation acidity in the region is caused by the growing concentrations of sulfates and nitrates in precipitation. Transboundary transport determines about 60% of the concentration of sulfates and nitrates in the precipitation over the south of the region. Impact of marine aerosol on the chemical composition of precipitation is significant at some coastal stations only.

Seasonal and long-term variations in the concentrations and discharge of dissolved nitrogen compounds and other biogenic substances by the Razdol'naya River runoff in the last 20 years are considered. The Razdol'naya River is one of the major rivers in the region, and its basin is subject to intense economic development. The natural and anthropogenic factors that affect variations in the concentrations of biogenic substances are characterized. The seasonal variations in the discharge of biogenic substances is shown to be controlled mostly by variations in water discharge.