Accumulation of weathered p,p'-DDE in mosses

DDT (2,2-bis(chlorophyll)-1,1,1-trichloroethane) is one of the persistent organic pollutants that is frequently used as a synthetic pesticide. DDT and its metabolites DDD (2,2-bis(chlorophenyl)-1,1-dichloroethane) and DDE (2,2-bis(chlorophenyl)-1,1-dichloroethylene) are still found in soil samples due to its past usage. Cucurbita pepo ssp pepo is known to be a good accumulator of these pollutants from the soil compared to other plant species. In addition, moss is a living organism that absorbs pollutants such as heavy metals and chlorinated organics in the atmosphere and is used as bioindicators in monitoring environmental pollution. The uptake mechanism of Cucurbita pepo ssp pepo, which is one of the zucchini plants used in the remediation of soils contaminated with organochlorine pesticides such as p,p'-DDE has not been well understood yet. There is no controlled study on the accumulation of p,p'-DDE from the soil by moss used as bioindicators. In this study, the ability of moss used as a bioindicator from p,p'-DDE contaminated soil and its effect on p,p'-DDE accumulation in Cucurbita pepo ssp pepo which is known to be a hyperaccumulator plant was evaluated by controlled pot experiments. Pot experiments were designed as p,p'-DDE contaminated soils have concentrations as 2358.82 and 1779.10 ng/g dry weight are named as group A and B, respectively. Both pot groups had 4 treatment sets and each pot contained around 1800 grams of p,p'-DDE contaminated soil. Golden Zucchini plants were grown in the pots as control plant sets and the control moss sets contain thallus moss placed on the contaminated soils, while the control groups only contained contaminated soils. In plant and moss sets, mosses were placed on the plant growing soil surface. After a 45-day growth period, the plants were harvested. The p,p'-DDE content of root, stem, leaf and moss extracts was measured by GC/µ-ECD. The results showed that in both group A and B, the amount of p,p'-DDE in plant roots decreased by 70%, 55% in stem samples, and 48% in leaf samples in the presence of moss. On the other hand, the p,p'-DDE concentration in the moss samples was detected on average 55% less than that of the control moss set. In conclusion, the moss significantly prevented the transfer of p,p'-DDE from the soil to the plant.