Occurrence of selected organochlorine pesticide residues in surface sediments from the Velke Kozmalovce, Ruzin, and Zemplinska Sirava water reservoirs, Slovakia

Abstract

Surface sediment samples from three water reservoirs of Slovakia were analyzed for selected organochlorine pesticides (OCPs). Concentrations of total dichlorodiphenyltrichloroethanes (ΣDDTs) in the sediments from Velke Kozmalovce, Ruzin, and Zemplinska Sirava ranged from 12 to 24 ng g -1 , 5 to 28 ng g -1 , and 1 to 20 ng g -1 , respectively, with the exception of one sediment sample from Zemplinska Sirava, having anomalously high concentration of ΣDDTs (526 ng g -1 ). Concentrations of hexachlorobenzene (HCB) in the sediments from these water reservoirs were generally lower and ranged from 0.3 to 9 ng g -1 . Other organochlorine pesticides such as mirex, lindane and heptachlor were not detected in the surface sediments. Ratios of DDT/(DDE + DDD) were lower than 1.0 in majority of the sediment samples indicating that the degradation of the parent DDT occurred significantly and DDT in the sediments from the studied water reservoirs was derived mainly from the weathered agricultural soils. Moreover, ratios of DDD/DDE indicated that the parent DDT was degraded under aerobic conditions before depositing into the sediments of these water reservoirs. . Iné v sedimentoch sledované organochlórované pesticídy ako mirex, lindán a heptachlór neboli zistené. Vo väčšine vzoriek sedimentov boli hodnoty pomeru DDT/(DDE + DDD) nižšie ako 1, z čoho sa dá usúdiť, že väčšia časť pôvodne prítomného DDT sa rozložila na jeho hlavné metabolity a že DDT v sedimentoch vodných nádrží pochádza najmä z erodovaných poľnohospodárskych pôd. Hodnoty pomeru DDD/DDE ukázali, že predtým ako bol DDT deponovaný do sedimentov vodných nádrží, rozkladal sa najmä za aeróbnych podmienok.KĽÚČOVÉ SLOVÁ: organochlórované pesticídy, DDT, dnové sedimenty, vodná nádrž, organická hmota.

Distribution of Organochlorine Pesticide Residues in Surface Water and Sediments of Ogun River at Kara Abattoir, Ogun State, Nigeria

“…Positive correlation was observed between the mean OCPs in water A samples and the corresponding sediment samples (r = +0.589, p > 0.05). This confirms the role of the sediments as a major sink of pollutants (Doong et al, 2002, Hiller et al, 2011. According to Doong et al (2002), persistency of OCP residues in sediment is possible due to their low solubilities in water and tendency to be adsorbed on suspended particulate matter and benthic sediments.…”

Levels of Organochlorine Pesticides in Brackish Water Fish from Niger River, Nigeria

“…The ratio of DDD/DDE can reveal the degradation pathways of DDT, since DDE and DDD are aerobic and anaerobic degradation products of DDT, respectively. A ratio of DDD/DDE less than one (<1) shows aerobic degradation and higher than 1 (>1) shows anaerobic degradation [ 29 , 30 ]. In the fish samples where DDD and DDE were simultaneously detected, the DDD/DDE ratio in the fishes sampled was more than 1 in all cases.…”

Levels of selected pesticides and trophic transfer of DDTs through the aquatic food web in the Lake Ziway ecosystem

“…Likewise, many studies have found Ʃ-DDTs to be the highest in concentration compared to other OCPs measured in freshwater fish with p,p′ DDE the most abundant and persistent of the metabolites analyzed (Wepener et al, 2012;Mzoughi et al, 2016). The studies by Hiller et al (2011) and Mzoughi et al (2016) have shown that p,p'-DDE is resistant against degradation so that it persists in the environment and living organisms. Degradation of p,p′ DDT by the process of mixed-function oxidases to the metabolite p,p′ DDE could be a good explanation for high levels and accumulation of p,p′ DDE in biota (Schmitt et al, 1990).…”

“…Moreover, the ratio of DDD/DDE can reveal the degradation pathways of DDT, since DDE and DDD are aerobic and anaerobic degradation products of DDT, respectively (Aislabie, 1997). A ratio of DDD/DDE less than one (<1) shows aerobic degradation and higher than 1 (>1) shows anaerobic degradation (Hiller et al, 2011). In the present study zooplankton and fish (Clarias gariepinus) samples where DDD and DDE were simultaneously detected, the DDD/DDE ratio in the biota sampled was much less than 1 in all cases.…”