The legacy of persistent organic pollutants in Azerbaijan: an assessment of past use and current contamination

Abstract

Azerbaijan has a history of production and heavy use of organochlorine pesticides (OCPs) with use focused in the main agricultural lowland region centred on the Kur River. Using a number of data sources, including archived reports from several government ministries, we attempt to construct production and use inventories for dichlorodiphenyltrichloroethane (DDT) and HCHs and compare these to scientific estimates of production and use of these chemicals in the 1960s to the 1980s. Notable discrepancies are evident particularly for DDT, with Azeri government records indicating much higher use (147-fold) than that estimated by the international scientific community. Soil and river sediment data from the 1980s and 2000s are also presented. While it is recognised that analytical uncertainties remain high for these older data (generated by GC-ECD), there is some evidence to show a decline in concentrations for some OCPs over this period. Extremely high concentrations of OCPs are evident for soils sampled in the vicinity of obsolete pesticide storage sites (found in numerous locations around the agricultural lowlands) and these levels may pose a health risk to wildlife and humans. River sediment data indicate high levels of both OCPs and polychlorinated biphenyls (PCBs), particularly downstream of the confluence of the two main rivers, the Kur and Araz. Particle-bound annual fluxes from the Kur River into the Caspian Sea are estimated for PCBs and OCPs and these are likely to influence levels observed in local coastal sediments, with agreement between river sediment data generated in the early 2000s and coastal marine sediment data generated from separate studies. We recommend that monitoring efforts should focus on soils in agricultural areas and around pesticide storage and production facilities as these soils will continue to provide a source of POPs to the regional environment.

Residues of Persistent Organic Pollutants (POPs) in Agricultural Soils Adjacent to Historical Sources of Their Storage and Distribution—The Case Study of Azerbaijan

“…[4,6,7,19,[25][26][27]. As mentioned before, the data reported by Aliyeva [28] from Azerbaijan were much lower than our results, but these studies were carried out in other area of Azerbaijan. According to Li et al [29], the total amount of DDTs used in the Azerbaijan in the years 1946-1990 was assessed as 250,000-520,000 tones.…”

“…The concentrations of Σ3HCHs were much lower than those observed for DDTs and ranged from 0.1 × 10 −4 µg kg −1 to 166.7 µg kg −1 . Alyieva et al [28] reported lower concentrations of HCH in soils in Azerbaijan, varying in the range 0.9 × 24.5 µg kg −1 . The dominant compound was α-HCH, which contributed about 73 % of the Σ3HCHs, followed by β-HCH and γ-HCH ( Table 1).…”

“…The isomeric composition of DDT can be influenced substantially by different environmental processes. The abundance of 2,4'-DDE and 4,4'-DDE in samples indicates their environmental degradation in the processes of weathering and aging [28,30], which may be related to microbial activity, sorption by organic matter or the influence of other environmental factors. [27,31].…”

The legacy of pesticide pollution: An overlooked factor in current risk assessments of freshwater systems

“…These transport routes are primarily initiated during heavy precipitation events and lead to transient peak concentrations often exceeding current ecological quality criteria (Bundschuh et al 2014;Liess and von der Ohe 2005;Schulz 2004). In contrast, legacy pesticides may enter surface water continuously via groundwater inflow (Barth et al 2007;Gilliom 2007;McKnight et al 2015), atmospheric deposition (Konstantinou et al 2006;Weber et al 2010) or through continuous leaching from agricultural soils and landfills (Aliyeva et al 2013).…”

“…Based on water samples mainly analysed for herbicides and four sediment samples mainly analysed for insecticides, McKnight et al (2015) suggested that legacy pesticides could still be prominent players driving observed impairments of freshwater invertebrates, and the authors urged for more extensive studies that allow for quantifying the predicted toxicological potency of legacy pesticides in comparison to current use pesticides. To our knowledge, such an extensive study of the potential toxicity of legacy pesticides to aquatic biota relative to that of contemporary pesticides is still lacking despite a substantial body of literature addressing the occurrence, concentrations and predicted toxicities of selected legacy pesticides (Aliyeva et al, 2013;Gilliom, 2007;McKnight et al, 2015;Weber et al, 2010). The novelty element is therefore to quantify the possible toxicity of legacy pesticides as an integral part of current risk assessment.…”