Studies on intercorrelation between selected persistent organic pollutants (POPs) and ions in sea water from the coastal zone of the Baltic Sea, Gdansk Bay region

The Baltic Sea is a semi-enclosed brackish sea with only limited water exchange with the North Sea and, thus, the North Atlantic. This salty water reservoir with water residence time of approximately 25 years is contaminated with many inorganic and organic pollutants: VOCl (Volatile Organohalogen Compounds), HC (Petrolcuin Hydrocarbons), OPNP (Organophosphorus and Organonitrogenous Pesticides), OCP (Organochlorine Pesticides), PAH (Polycyclic Aromatic Hydrocarbons) and heavy metals. Our paper presents monitoring results and sea environmental pollution assessment of the Southern Baltic coastal zone- the area of the Gdansk Bay, based on the analysis of sea water samples. A set of various analytes were determined: PAH (16 analytes), VOCl (6 analytes), HC (9 analytes), OPNP (8 analytes), OCP (5 analytes), heavy metals (Zn, Cd, Ph, Cu). The results were subjected to full statistical evaluation. An assessment of sea environment contamination was made by characterization of pollution sources and the definition of intercorrelations between them. The characterization of major statistically important correlations between 45 variables was performed with the use of principal component analysis technique. From the performed PCA it arose that the factor configuration was similar for all sampling points and in all cases 5 factors explain over 60% of the data variance, and the statistically significant loading factors are higher than 0.7 (with p=0.05). Additionally, analysis of variance and time series analysis were applied to define important differences between chemical species' concentration levels in time and in accordance with sampling points' geographical location. As a result of time series analyses carried through with consideration to sampling points, there were no statistically important differences discovered in trends of changes from 1996 up to 1999 for any of examined groups of compounds.