Isolation of compounds from bleached kraft mill recovery condensates associated with reduced levels of testosterone in mummichog (Fundulus heteroclitus)

Abstract

Previous studies have identified chemical recovery condensates as a primary source of hormonally active substances within a Canadian bleached kraft pulp mill. Although reverse osmosis treatment of condensates raises the exposure threshold that alters circulating levels of testosterone in mummichog (Fundulus heteroclitus), the responsible chemicals have not been characterized. In this study, a solid-phase extraction (SPE) method was developed to isolate chemical recovery condensate extractives for evaluation of hormonal activity. Condensates generated during softwood and hardwood pulp production were investigated for their relative potential to affect both circulating and gonadal production of sex steroids in mummichog. Mummichog were exposed to whole condensates, extracts from suspended particulates (> 1 microm), two fractions from SPE, and residual condensates after SPE. The distribution of bioactivity among condensate fractions was similar for both wood furnishes. In both sexes, significant depressions in circulating testosterone and in in vitro gonadal testosterone production were associated with exposure to whole condensates, particulate extracts, one SPE fraction, and residual material after SPE. An optimized SPE method subsequently demonstrated complete recovery of polar, bioavailable chemicals that reduced testosterone levels in both sexes. Characterizations of active fractions by gas chromatography-mass spectrometry (GC-MS) showed the presence of extractives with molecular masses > or = 240 amu possessing functionalities consistent with lignin degradation products. This study provides the first isolation of chemicals derived from pulp production associated with impaired reproductive performance in fish.

Reproductive Steroid Responses in Fish Exposed to Pulp Mill Condensates: An Investigation of Cause Case Study

“…Future work focused on the SPE-2 fraction since it exhibited the greatest potential for depressing hormones in both sexes. A comparison study showed that condensates derived from both hardwood and softwood batch production runs at IPP had an equal potential to lower hormone levels (Hewitt et al 2002). In terms of identifying characteristics of the compounds involved, this evidence showed them to be organic, water soluble, and readily bioavailable to fi sh.…”

“…A solid-phase extraction (SPE) method was developed by Hewitt et al (2002) to isolate chemical recovery condensate extractives for the evaluation of their hormonal activity. In this work, hormone depressions in mummichog were used to direct SPE method development.…”

“…During the exposure period, water is completely renewed and extracts/effl uents are re-administered every 24 hours for 7 to 14 days to each tank by netting fi sh from each tank, placing them momentarily in a bucket, emptying and refi lling the tanks, and replacing the fi sh. Seven-day exposures have been shown to be adequate for eliciting responses in endocrine status in mummichog exposed to pulp mill effl uents and model compounds (Hewitt et al 2002;MacLatchy et al 2003). Extracts are dissolved in methanol; reference tanks receive equivalent doses of methanol (0.0125% vol/vol) for control purposes.…”

“…Studies conducted at Irving Pulp and Paper Ltd., a bleached kraft pulp mill in Saint John, New Brunswick, Canada, were some of the fi rst to implement an investigation of cause approach (Hewitt et al 2003) for identifying specifi c hormonally-active waste streams within the mill (Dubé andMacLatchy 2000a, 2001;Hewitt et al 2002;Belknap et al 2006;Shaughnessy et al 2007). Since 1997, our objectives at this mill have been to: 1) identify the sources within the mill processes of contaminants that cause reproductive responses; 2) characterize the causative compounds within the source waste stream(s); and 3) identify potential technological solutions that improve effl uent quality at end-of-pipe.…”

Reproductive Disruption in Wild Longear Sunfish ( Lepomis megalotis ) Exposed to Kraft Mill Effluent

“…Organic compounds in the wood itself are the most likely cause of reproductive suppression (Dube and MacLatchy 2001). Hewitt et al (2002) showed that compounds derived from both hardwoods and softwoods caused similar suppressive effects.…”