Evaluation of Acute Toxicity and Genotoxicity of Liquid Products from Pyrolysis of Eucalyptus grandis Wood A. S. Pimenta, 1 J. M. Bayona, 2 M. T. Garcı ´a, 3 A. M. Solanas 4 1 Department of Forestry Engineering, Laboratory of Wood Energy and Technology, Federal University of Vic ¸osa, Campus Universita ´rio, 36571-000, Vic ¸osa (MG), Brazil 2 Department of Environmental Chemistry, IIQAB-CID-CSIC, Jordi Girona 18, E-08034 Barcelona, Spain 3 Department of Surfactant Technology, IIQAB-CID-CSIC, Jordi Girona 18, E-08034 Barcelona, Spain 4 Department of Microbiology, University of Barcelona, Avda, Diagonal, 645, 08028-Barcelona, Spain Received: 20 April 1999/Accepted: 27 July 1999 Abstract. Slow pyrolysis of Eucalyptus grandis wood was performed in an oven laboratory, and smoke was trapped and condensed to yield liquid products. Polycyclic aromatic hydro- carbons (PAHs) and phenolic fractions were isolated from the former liquid products using adsorption column chromatogra- phy (ACC) and identified by GC/MS. Concentrations of PAH and phenolic fractions in total pyrolysis liquids were respec- tively 48.9 μg/g and 8.59% (w/w). Acute toxicity of total samples of pyrolysis liquids and the phenolic fraction was evaluated by means of two bioassays, namely, 24-h immobiliza- tion bioassay with Daphnia magna and Microtox bioassays, the latter employing the luminescent bacteria Photobacterium phosphoreum. Total pyrolysis liquids and the PAH fraction were evaluated for genotoxicity by the Microtox bioassay conducted using rehydrated freeze-dried dark mutant of the luminescent bacteria Vibrio fisheri strain M169. Total pyrolysis liquids and the phenolic fraction, respectively, in concentrations of 170 and 68 mg/L were able to immobilize 50% (EC 50 ) of the D. magna population following 24-h exposure. Concentrations of 19 and 6 mg/L, respectively, for total pyrolysis liquids and phenolic fraction were the effective concentrations that resulted in a 50% (EC 50 ) reduction in light produced by bacteria in the Microtox bioassay. Accordingly, the Microtox bioassay was more sensitive to toxic effects of both kind of samples than the D. magna bioassay, particularly for the phenolic fraction. Regarding to the genotoxicity evaluation, the results achieved by Microtox bioassay showed that total pyrolysis liquids had no genotoxic effects with and without exogenous metabolic activation using rat liver homogenate (S9). However, the PAH fraction showed toxic effects with rat liver activation and had a dose-response number (DRN) equal to 1.6, being in this way suspected genotoxic. The lowest detected concentration (LDC) of the PAH fraction able to cause genotoxic effects was 375 μg/L. Near 6.8 million tons of charcoal are consumed every year in Brazil, and 54% of this overall amount is produced by using wood from Eucalyptus planted forests as raw material (ABRA- CAVE 1997), basically from the species E. grandis. Metalwork sector, including pig iron, steel, and iron alloy industries, consume 85% of overall charcoal, constituting the so-called tropical metallurgy. Most industrial wood carbonization plants currently operating in Brazil are oriented to charcoal production by means of partial-combustion masonry kilns that do not recover the by-product gases and condensable compounds. In fact, mass and energy yields are very poor in the conventional kilns, about 33 and 50%, respectively, especially when by- products are not recovered for recycling (Resende et al. 1994). Normally, in the slow pyrolysis process, the losses as smoke based on initial wood mass can reach about 50–55% of the initial carbon, 75–52% of the initial hydrogen, and 87–90% of the initial oxygen as smoke (Wenzl 1970; Almeida 1982). When released from industrial plants to the environment, pyrolysis volatiles promote substantial air, ground, and water pollution. Contaminants occurring in the pyrolysis smoke are divided into three main groups: suspended solids, noncondensable gases, and condensable organic compounds. The chemical nature of the compounds found in the last group of pollutants has been increasingly studied because a better understanding of the characteristics and properties of such effluents is important to develop suitable devices for reducing pollutant emissions, such as condensers, burners, or filtering systems. During thermal decomposition of woody biomass, part of the smoke from the pyrolysis bed can be condensed, yielding a liquid that after standing separates to two phases: an aqueous phase containing alcohols, ketones, and other low-molecular- weight volatile compounds, and an oily phase–denominated wood tar that is composed mainly by moisture, wood creosote (phenols mixture), and 30–50% of a polymeric pitch (Carazza et al. 1991). Apart from water, wood tar contains condensable semivolatile and nonvolatile compounds with molecular weights varying from acetic acid (M W = 60) to tar pitch (M W  500). More than 400 different compounds have been identified in pyrolysis tars (Pakdel and Roy 1988, 1991; Desbe `ne et al. 1991), and several of them, such as the polycyclic aromatic Correspondence to: J. M. Bayona Arch. Environ. Contam. Toxicol. 38, 169–175 (2000) DOI: 10.1007/s002449910022 ARCHIVESOF E nvironmental Contamination and T oxicology  2000 Springer-Verlag NewYork Inc.