Biomarkers of PAHs exposure in crabs Ucides cordatus: Laboratory assay and field study Adriana H. Nudi a , Angela de L.R. Wagener a,n , Eleine Francioni a,1 , Carla B. Sette a , Andre ´ V. Sartori b , Arthur de L. Scofield a a Departamento de Quı ´mica Pontifı ´cia Universidade Cato ´lica do Rio de Janeiro, Rua Marques de S ~ ao Vicente 225, 22453-900 Rio de Janeiro, RJ, Brazil b Departamento de Saneamento e Sau ´de Ambiental Escola Nacional de Sau ´de Pu ´blica, FIOCRUZ, RJ, Brazil article info Article history: Received 11 March 2009 Received in revised form 11 September 2009 Accepted 28 October 2009 Available online 19 January 2010 Keywords: Pyrene metabolites Micronuclei Ucides cordatus Mangrove Oil contamination abstract Pyrene metabolites in urine and micronucleus in haemocytes of crabs (Ucides cordatus) were tested as biomarkers of exposure to oil derived PAHs in mangrove sediments. The goal was to verify how well pyrene metabolites in urine represent levels of oil contamination in mangroves and whether the micronuclei assay indicates exposure. For this, bioassays were performed using crabs from clean and contaminated areas, and field studies were conducted in four mangroves. Results of the bioassay show that U. cordatus assimilates, metabolises, and excretes pyrene in urine as pyrene-1-glucoside, pyrene- sulphate and pyrene-conjugate. OH-pyrene-sulphate was the major metabolite produced/excreted over 120 h of observation by crabs from the clean mangrove. The production/excretion of pyrene- 1-glucoside in this case increased linearly with time at a rate of 2.3  10 10 mol L 1 day 1 . The number of micronuclei in haemocytes also increased with the time after pyrene inoculation, indicating that exposure to pyrene triggers genotoxic and mutagenic response. In crabs from a heavily oil- contaminated mangrove pyrene-1-glucoside was the major metabolite, an indication that production/ excretion of a certain metabolite varies depending on adaptation of the animal to the environment. A highly significant correlation was found between the concentration of pyrene metabolites in urine of field crabs expressed as OH-pyrene equivalents and the sum of 38 PAHs determined in hepatopancreas/ sediments (r = 0.825, n =23, p o0.05). The response of these crabs to the micronuclei assay was not significantly related to concentration of individual or total PAHs. Nevertheless, metabolite results prove U. cordatus as excellent bioindicator for evaluating environmental quality in mangrove areas as related to PAHs and oil contamination. & 2009 Elsevier Inc. All rights reserved. 1. Introduction Aromatic polycyclic hydrocarbons (PAHs), which are consid- ered carcinogenic and mutagenic compounds (Aas et al., 1998; Wang et al., 1999), originate from petrochemical activities, incomplete combustion processes and natural sources. Toxicity is principally caused by PAHs metabolites rather than the parental compounds (Krone et al., 1992; Baird, 1999); therefore these metabolites are good exposure biomarkers and can be used as a convenient tool for environmental risk evaluation (Stroomberg et al., 1999). Amongst the several PAHs, pyrene is considered a good indicator of the presence of hydrocarbons in the environ- ment. This compound, found in relatively high concentrations in water and sediment, shows intense fluorescence being easily detected by analytical techniques based on this phenomenon (Watson et al., 2004). It has a relatively low toxicity and carcinogenicity, making laboratory experiments easier (Stroom- berg et al., 1999; Eickhoff et al., 2003). The analysis of pyrene metabolites using fluorescence has shown to be a sensitive method for indicating fish exposure to PAHs. Currently it is the most frequently used method for the rapid evaluation of hydrocarbons in these organisms. Some practical applications in biomonitoring based on this technique are presented by several authors (Krahn et al., 1993; Lin et al., 1994; Beyer et al., 1996; Goksøyr et al., 1996; Escartin and Porte, 1999; Aas et al., 2000; Dissanayake and Galloway, 2004). Although biomarkers are likely to be used as a tool in regular environmental evaluations and in extraordinary events such as an oil spill, selection of appropriate organism and testing to under- stand reactions to targeted toxicant need to be carried out before routine application. The majority of studies with such goal have been performed in areas of temperate climate while very little is known about bioindicators in tropical regions and their response to PAHs exposure caused by oil contamination. ARTICLE IN PRESS Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/envres Environmental Research 0013-9351/$ - see front matter & 2009 Elsevier Inc. All rights reserved. doi:10.1016/j.envres.2009.10.014 n Corresponding author. E-mail address: angela@puc-rio.br (A.d. Wagener). 1 Present address: Laborato ´ rio de Quı ´mica Ambiental, PETROBRAS/CENPES/ PDEDS/AMA, 21941-598 Rio de Janeiro, RJ, Brazil. Environmental Research 110 (2010) 137–145