TOTAL CHROMIUM AND HEXAVALENT CHROMIUM IN AIR FROM SOLID TANNERY WASTES AND HEALTH RISKS FOR SLUM POPULATION IN BANGLADESH

Over 280 tanning industries are located in Hazaribagh area in the outskirt of Dhaka city in Bangladesh. These tanning industries process about 74,000 tons of raw hide annually and export $400 million worth of lather. A variety of acids and chromium salts are used in the tanning process of raw hides. Approximately 22,000 cubic meter of untreated liquid wastes and industrial effluents are dumped in the nearby river Buriganga. Solid wastes such as discarded hides, hair pollute the local streets. In addition to occupational exposure for working people, general population is exposed to chromium and chromium species through air and water. Chromium (III) is essential trace element, however, hexavalent chromium Cr(VI) is a known carcinogen. Slum residents near the tanning industries often use discarded hides and shaving of hides as fuel for cooking causing indoor air pollution and release chromium in air. In our study, water samples near the industrial discharge and in the downstream river water were analyzed for chromium. Total chromium in ambient and indoor were determined by collecting particulates in air and analysis of chromium in particulates by electrothermal atomic absorption spectroscopy. In addition, speciation of Cr in particulate matters collected in air filters were carried out through ion chromatography and inductively coupled plasma mass spectrometry (IC-ICP-MS). Air sampling in ambient air and indoor air in slum households near tanning industries were carried out using a low volume air sampler (Minivol, Airmetrics Co, Oregon, USA). The Cr level in air samples collected near tanning areas were significantly (p < 0.050) higher than Cr levels in control areas far removed from tanning industries. Total Cr and Cr(VI) in water, ambient, indoor air and potential health risks will be discussed in this presentation.