Pulp and paper mill effluents induce distinct gene expression changes linked to androgenic and estrogenic responses in the fathead minnow (Pimephales promelas)

Abstract

Although effluent treatment systems within pulp and paper mills remove many toxicants and improve wastewater quality, there is a need to understand and quantify the effectiveness of the treatment process. At a combined news and kraft pulp and paper mill in northwestern Ontario, Canada, fathead minnow (FHM) reproduction and physiology were examined before, during, and after a short-term (6-d) exposure to 10% (v/v) untreated kraft mill effluent (UTK), 25% (v/v) secondary treated kraft mill effluent (TK), and 100% (v/v) combined mill outfall (CMO). Although UTK exposure significantly decreased egg production, neither TK nor CMO caused any reproductive changes. The expression of six genes responsive to endocrine-disrupting compounds, stress, or metals was then examined in livers of these fish using real-time polymerase chain reaction. In female FHMs, none of the three effluents induced significant expression changes in any genes investigated. By contrast, in males there were significant increases in the mRNA levels of androgen receptor, estrogen receptor (ER) beta, and cytochrome P4501A (CYP1A) upon UTK and TK exposure but no changes in ERalpha or vitellogenin (VTG) gene expression, whereas CMO exposure significantly increased the mRNA levels of ERalpha, VTG, and CYP1A. Together, these results suggest that kraft effluent before and after biological treatment contained compounds able to induce androgenic effects in FHMs, and that combination of kraft and newsmill effluents eliminated the androgenic compounds while inducing distinct and significant patterns of gene expression changes that were likely due to estrogenic compounds produced by the newsmill.

Sensitization of vitellogenin gene expression by low doses of octylphenol is mediated by estrogen receptor autoregulation in the Bombina orientalis (Boulenger) male liver

“…Furthermore, effluent from sewage treatment plants on the Yeongsan and Seomjin Rivers has been shown to contain OP at a level as high as 0.5 ng/L (2.42 nM) (Duong et al, 2010). Another study found that ER␣ and VTG transcription was induced by exposure to paper mill outfall in male fathead minnow (Pimephales promelas) (Werner et al, 2010). Moreover, increased plasma VTG levels have been reported in male R. catesbeiana in Korea (NIER, 2003).…”

The effects of estrogenic and androgenic endocrine disruptors on the immune system of fish: a review

“…Similarly, other studies noted the occurrence of masculinization in fish that were downstream of bleached kraft pulp and paper effluent point sources. This effect was due to the interaction of androgen-like compounds with the androgen receptor AR (Parks et al 2001;Larsson et al 2006;Wartman et al 2009;Werner et al 2010). In laboratory studies, the agonist and/or antagonist effects of many chemicals have been tested using either in vitro, in vivo, or both types of assay (Table 1).…”

Probing the xeno-oestrogenic impact of sediment cores contaminated by the pulp and paper industry: induction of aromatase cyp19a1b in late larval zebrafish

“…Werner et al 2010). In our studies, sediments from sites 1 km and 3 km downstream of the mill failed to induce cyp1a in juvenile zebrafish, when compared to the upstream reference site (RN).…”