Distribution of Organochlorine Compounds in Pine Needles Collected at Urban Sites in Croatia

Abstract

Six indicator congeners of polychlorinated biphenyls (PCB-28, PCB-52, PCB-101, PCB-138, PCB-153, PCB-180) and organochlorine compounds hexachlorobenzene (HCB), alpha-, beta- and gamma-hexachlorocyclohexane (alpha-, beta- and gamma-HCH), 4, 4'-DDE, 4, 4'-DDD, nad 4, 4'-DDT were measured in pine needle samples collected during January - March 1998 at 16 urban sites in Croatia. All compounds were found in all samples. Organochlorine pesticides ranged between 0.05 and 5.93 ng/g dry weight and PCBs 0.12-8.31 ng/g dry weight. Levels of analysed compounds were not particularly high or particularly low at any single site. In most samples the alpha-HCH/gamma-HCH ratio was below 0.9, and in some samples the DDE/DDT ratio was close to or below 1. This indicated a recent input of gamma-HCH and DDT in the atmosphere.The investigation of temporal trends in concentrations was based on data obtained by analysis of samples collected at the same site from the same pine tree in 2000 and in 1992. Samples were collected at five sites. All analysed organochlorine pesticides were found in all samples collected in 2000 in the range between 0.03 and 1.2 ng/g dry weight. The comparison of concentration medians in 2000 and 1992 indicated a slight decreasing trend with some exceptions: in 2000 the concentration of beta-HCH was higher than in 1992, and the DDE/DDT ratio decreased in some samples.