Investigation of drug contamination on sediments of Santos and São Vicente estuary system, Santos Bay and adjacent continental shelf

Abstract

The production and use of pharmaceuticals have increased in the last decades but little is known about these compounds and their behavior in the aquatic environment, where, in general, they are discharged. Some of them may interact with hormones and endocrine systems of the natural aquatic biota and, therefore, are called endocrine disrupting compounds. A sub-group of the endocrine disrupters are the reproductive hormones, used extensively in oral contraceptives and estrogen-replacement therapy and have been implicated in changes in the male reproductive tract, female gynecological system, human fertility, thyroid function, and the central nervous system. Some examples of endocrine disruptors include 17beta-estradiol, estrone, and 17alpha-ethynylestradiol that may exhibit great recalcitrance to biological wastewater treatment schemes. In fact, they were already detected in domestic sewage and effluents of treatment plants in Rio de Janeiro. This proposal objective to investigate the presence of the pharmaceuticals and metabolites that work as endocrine disruptors, such as the reproductive hormones and steroids, in the sediments sampled nearby of the great complex Santos-Cubatão. This estuarine region continually receives great volume of water and sewage, from all cities around, heavily concentrated in urban, tourism and industrial activities. Over the course of a year we will investigate the presence and behavior of a subset of endocrine disrupting compounds, including several reproductive hormones (e.g. 17beta-estradiol and estrone), and some sterols such as coprostanol and cholesterol. These compounds, if detected in sediments, have a potential influence over the water quality, ecosystem and biota health of the estuary, bay, and adjacent continental platform. The sediment samples were already collected inside the ECOSAN (PRONEX-CNPq/FAPESP no 03/09932-1) and BIOTASP/FAPESP (no 98/05068-0) projects. The compounds identification will be done by the gas chromatography / mass spectrometry technique. This proposal presents a new research line that will contribute in a great way to the oceanographic scientific community, with precious information in the marine pollution field. In addition, a powerful analytical methodology, totally new in Brazil, will be implemented, and it will be a great tool for the future evaluation in other areas along the Brazilian coast. (AU)