The main stationary sources are concentrated around five big cities in Moldova: Chisinau, Balti, Rezina, Ribnita and Tiraspol and in the town of Dnestrovsc. In cities road traffic is relatively dense, causing the immediate and short-term exposure of the urban population to its emissions.  Therefore, air pollution problems occur primarily in these areas.

Available monitoring data for four major cities, except Rezina (Table 10.1), provided by the Hydrometeorological Service (Hidrometeo), indicate that since 1993 concentrations of nitrogen dioxide and nitrogen oxide have gradually risen at most measurement points.  In Chisinau in particular they exceeded the WHO annual guideline for NO2 in 1996. The annual levels of sulphur dioxide in the years 1992-1996 were also above the WHO guide value in Balti, but in other cities they were well below.

In general, relatively high annual concentrations of particulate matter or TSPs prevail in all monitored cities, exceeding three to four times present WHO guidelines.  Although their values may be higher than emission estimates suggest (poor maintenance of roads and soil erosion can contribute as diffuse sources), it is known that suspended particulates contain much lead, benzo(a)pyrene and possibly other carcinogenic components emitted mainly by city traffic.  Except for point measurements of aldehydes, phenol and sulphates, they are unfortunately not monitored or analysed at all.

Table 10.1:  Trends in ambient air quality in main cities, 1990-1996

 
Source:  Department for Statistics.

This is mainly due to the extremely poor equipment of the laboratories visited, which are condemned to using simple sampling and analytical methods that do not correspond to those recommended by the EMEP centres.  In general, their situation has deteriorated since the independence of the Republic and they are unable to cooperate at international level.

At current levels of nitrogen oxides and other traffic-related pollutants, particularly during shorter exposures, when standard levels are exceeded  much more, the urban population runs the risk of health problems.

Heavy metals and volatile organic compounds (VOC) are not monitored. All city monitoring stations were located and equipped at the time and according to the criteria of the former USSR. Air sampling is done three times a day (except one night sampling at one station in the capital) followed by chemical analysis at the laboratory.  No station is equipped with automatic measuring devices.

City monitoring is complemented by measurement of wet deposition acidity, but only one meteorological station in Hancesti has recorded results systematically.  They showed fluctuations in pH from 3.80 to 10.35 in 1995 and slightly rising acidity over the past few years.