2.3.2. Soil pollution
During 2002, soil samples from 8 districts of the Republic of Moldova were analysed for soil quality and residual quantities of pesticides. This monitoring programme involved all regions of the country and included investigations on 64 agriculture fields totaling 4616 hectares.
The data did not reveal any significant level of soil pollution with organochlorine pesticides. The average level of Σ DDT and Σ HCCH isomers under all crops on investigated fields was 0.016 ppm and 0.002 ppm, respectively (that corresponds to 0.16 and 0.02 from the maximum admissible concentration (MAC) for these pesticides). The maximum level of soil pollution with DDT, exceedind the MAC 2.3 times, was detected in Pirjota (Balti), in the North of the country, on a field with sugar beet. The maximum pollution level with HCCH (0.32 MAC) was found in the Edinet district, also in the North. Other cases of exceedance of existing standards for Σ DDT in soil were revealed in Tighina (7.6%), Orhei (3.3%), Soroca (23.3%) and Balti (3.8%) districts. The polluted area was estimated at 62.7 ha, 28 ha, 70 ha and 22.5 ha, respectively. In Chisinau, Cahul, Ungheni and Edinet districts no pollution with DDT and HCCH was detected (fig. 2.20).
No residual quantities of simm-triazine herbicides and deltametrin were found in the samples.
Fig. 2.20. Pollution of soils with DDT
The pollution of soils with copper is widespread in Moldova. Mobile copper was detected in all investigated regions but the Chisinau district. The average concentration of mobile copper in the suspended phase was 3.53 ppm (1.18 MAC) while the maximum (2.3 MAC) was recorded in a vineyard in the Cahul district (South of the country) (fig.2.21).
Fig. 2.21. Pollution of soils with copper
The analysis of data showed no exceedance of MAC for nitrates (130 ppm as NO3). The maximum level, 86 ppm, was recorded in the Tighina district. From the soil fertility perspective, the highest average concentration of nitrate was recorded also in the Tighina district, 10,0 ppm, while the minimum value (1.6 ppm), in the Ungheni district.
The maximum average level of potassium was found in the Edinet district (com. Alexeevca), 552 ppm K2O (this is exceeding the needs of the crops for potassium), the minimum level, in the Cahul district, 129 ppm K2O (this is a reduced level of potassium compared to crop needs).
The average soil content of mobile phosphorus (P2O5) varied between 96.8 ppm (Liadoveni, Balti), and 11.5 ppm (Sipoteni, Ungheni). The average humus content varied from 1.8%, in the Ungheni district, to 4.1%, in the Balti district.
In Moldova, the former storehouses for agrochemicals which have been dismantled after the cancellation of former collective farms, present a significant environmental concern. Laboratory investigations of the adjacent areas revealed a significant level of soil pollution. For example, at the chemicals storage in the village of Boscana (Chisinau district), the content of nitrates exceeded the MAC even at 200 m from the place. At this distance, also the concentration of carbophos is 3 times higher than the MAC while the content of organochlorine pesticides exceeds it 2-3 times. A significant level of pollution was revealed at the chemicals depo in Ustia (Chisinau district) where the MAC for organochlorine pesticides is exceeded 3.5-7 times at just 150 m from the building. A similar picture was found in many other places (e.g. Copaceni, Prepelita, Petrunea, Pruteni, Braniste, Petruseni, Saptebani, etc) where the MACs for mineral phosphorus was exceeded 1.1-44.1 times (depending on the distance from the storehouse and the deepness); for nitrates, 1.2-52.8 times; for potassium, 1.1-22.9 times; for organochlorine pesticides, 2.0-28.6 times; for organophosphorus pesticides, 5.8-20.6 times.
The investigations revealed in several places the contamination of soils with animal waste (especially in places where big livestock farms still exist) and oil products (especially in the proximity of storages and industrial sites).
A special issue in the Republic of Moldova is related to the places of former Soviet Army units where fuel for aircrafts and rockets and other highly toxic waste was stored. A number of cases of pollution of soils and groundwater sources with oil products and toxic substances were reported, in the military bases as well as the adjacent areas.
The most serious reported case of environmental pollution occurred at the Marculesti air base, Soroca district. According to the data provided by the Ministry of Defense, by the year 1992, about 500-600 tons of fuel was spilled off and penetrated into the soil. About 800 hectares of land were contaminated together with the groundwater horizons until the depth of 25-30 m.
Formerly, in the Republic of Moldova special rockets with silver nitrate or silver bromide charge were extensively used to combat hail which in summer quite often causes damages to the orchards and vineyards. As a result of the use of these rockets, in several places the land was polluted with highly toxic rocket fuel „Melanj” and „Samin” (see following table).
Table 2.5
The areas polluted with rocket fuel
Location / Polluted area, ha.Bacioi / 0.27
Toderesti / 0.02
Negresti / 0.01
Buteni / 0.01
Danceni / 0.50
Total / 0.81
In Parlita, Ungheni, on the place of an old military storage of petrol and diesel, the land was polluted with oil products on an area of 4.7 ha. The similar fuel storage in the city of Balti (10,000 tons) provoked the contamination of land on 3 ha.
The total area of contaminated soils on the territory of military units and the adjacent lands is:
- with petroleum products, 882.7 ha;
- with rocket fuel, 0.81 ha.