Gehalte aan PCB's en organochloorpesticiden in mariene organismen van de Belgische kustwateren

Polychlorinated biphenyls (PCBs) and some oranochlorine pesticides were measured in flounder, cod, sole, shrimps and mussels by capillary gaschromatography. PCBs predomiated among the organochlorine residues and represented 75 to 90 % of the global content. The average PCB-concentration in the wet tissue ranged from 39.5 ppb in shrimps to 261.1 ppb in mussels. From the group "DDT and its metabolites"only the derivates p,p'-DDE and p,p'-DDD could be quantified.The different organochlorine pesticides were present in concentrations generally below 5ppb in wet tissue.From the point of view of public health the organochlorine residues in marine organisms seem to present no risk

Trace metals in the Belgian dumping area for acid wastes from the titanium dioxide industry (1985-89)

During the period of investigation, two stations in the dumping site and six reference stations were monitored. In water and sediments only the iron content, a key parameter, was determined. In benthos, Fe, Cr, Ni, Zn, Pb, Cu and Cd were assessed. The iron content was very similar in both the dumping area and in five reference stations (0.06-0.08 mg/1). In the station nearest to the coast however, the concentrations were 2 to 3 times higher, showing the influence of river inputs. There was no temporal trend. A lack of dissolved oxygen was never observed and no marked differences between the eight areas were noted indicating that the oxidation of Fe++, the main component of the waste stream, had no measurable consequences in the water column. Abnormally low pH-values were not observed. In the sediments, no temporal trend in iron concentrations could be detected. No higher amounts were noted in the dumping area. The concentration of iron did not appear to be linked directly to the disposal of titanium dioxide waste but to input sources in general. The distance to the coast seems to play an important role. The iron content in the total mud fraction (<63 µm) decreased seawards (from ca 4.2 to 0.12 g/kg) up to about 20 nautical miles. In sea star (Asterias rubens), hermit crab (Pagurus bernhardus), swimming crab (Macropipus holsatus) brittle star (Ophiura texturata) and cut trough shell (Spisula subtruncata), there was neither a clear temporal trend nor evidence of accumulation of metals due to the dumping of titanium dioxide waste. Nevertheless, large amounts of heavy metals associated with particulate matter can be carried over long distances before being deposited. For this reason, all dumpings were banned since 1990

Tsunami's in de Noordzee: kan het?

A