Determinação de contaminantes emergentes e hidrocarbonetos policíclicos aromáticos: dispositivos de amostragem passiva em água

Abstract

Coastal environments located near urban and industrial centers are usually contaminated by compounds of anthropogenic origin, such as polycyclic aromatic hydrocarbons (PAHs) and emerging contaminants (CECs). In marine systems, the concentrations of these compounds are generally low due to processes such as dilution and degradation. However, the presence of these contaminants is of concern even at relatively low concentrations, as evidenced by the detection of biological effects at environmental levels. Among the different ways of monitoring these coastal environments, passive sampler devices (PSDs) have been widely studied to assess the presence of anthropogenic organic compounds in aquatic environments. Various models are being tested, such as the J-Flex® silicone strips used in this study. This study evaluated the applicability of this material for simultaneous monitoring of emerging and legacy compounds in the water column. To this end, an analytical method was developed for the use of PSDs in CEC contamination studies, and subsequently used in environmental studies. Analyte recovery tests, analytical method validation procedures and experiments based on the co-solvent method were carried out to estimate the analyte partition coefficient (KPW) of interest. This study determined the KPW for six fragrances (tetramethyl acetyloctahydronaphthalene - OTNE, phantolide - AHMI, tonalide - AHTN, celestolide - DPMI, galaxolide - HHCB, traseolide - ATII) and eight UV filters (benzophenone-3 - BP3, avobenzone - ABZ, octocrylene - OCT, 2-hydroxybenzophenone - 2OHBP, 4-methylbenzylidene camphor - 4MBC, homosalate - HMS, 2-ethylhexyl salicylate - EHS and 2-ethylhexyl methoxycinnamate - EHMC). The log KPW values obtained ranged from 4.46 (BP3) to 6.47 (EHMC). After a field test, the suitability of silicone rubber as a PSD was proven, with slower and more accurate balance being achieved. After all the stages of the analytical method had been validated, the PSDs were exposed in a region of Todos os Santos Bay (Bahia - Brazil), a tourist region with a strong presence of aquatic and nautical activities and included in a marine environmental park during one year. Freely dissolved concentrations ranged from 1.16 (DPMI) to 303 (HHCB) pg L-1 for fragrances and from 3.55 (2OHBP) to 4051 (HMS) pg L-1 for UV filters. For legacy contaminants, the sum of the freely dissolved concentration ranged from 9.39 to 1197 pg L-1 for PCBs, from <MDL (method detection limit) to 7.05 pg L-1 for organochlorine pesticides and from 3,759 to 21,975 pg L-1 for PAHs. According to the diagnostic ratios, the PAHs originate from mixed sources (pyrolytic and petrogenic). An environmental risk assessment was carried out for the chemical substances for which ecotoxicological data was available, indicating that UV filters and legacy contaminants represent the greatest potential risk to organisms. To complement this, a bibliographic survey using meta-analysis was carried out in order to investigate the responses of biomarkers in bivalve organisms to CECs, since in the literature there is a strong comparison between the assessment of contamination through passive samplers and this class of organisms. In general, the study revealed that the effects of the contaminants on these organisms is still unclear, but there are changes in the activities and levels of the major biomarkers in the presence of these compounds.