Pesticides in Dee Estuary Sediments, NW England; Implications for Pollution Study of Coastal Environments

Core samples from the sediments of the Dee Estuary were collect-ed from the chosen sites to study the distribution of pesticides in the sediments. The organic compounds were extracted by a microwave sample preparation system from 56 sediment samples and gas chromatography. Mass spectrometry (GC-MS) was employed for the organic compound analysis. Distribution of n-alkanes in the analysed sediments and calculation of their carbon preference index indicate a continental source for the organic compounds in all samples. Different search strategies were applied to find pesticides in the sediments. Maneb was the only pesticide found in the samples. The distribution of Maneb showed a zigzag pattern with depth in all the four studied areas in the Dee estuary, corresponding to the pattern of distribution of total organics. The highest concentration level of Maneb was 16.33 ng/g of sediment at a depth of 14 cm. The distribution of Maneb with depth is attributed to the seasonal application and release to the environment