Both types of effluent and all extraction media were linked with significant impacts to the brain tissues, indicating that a wide transaminase, acetylcholinestIf you’re reading this on paper, range of substances in the effluerase, and glutamic acid you may want to thank fish popuents was impacting the neurodecarboxylase (GAD). lations around the world for their chemical pathways. The researchers obtained sacrifices. Despite the paper in“These findings provide a novel samples of primary- and seconddustry’s efforts to reduce conand plausible mechanism by ary-treated effluent from an untamination, numerous studies which pulp and paper mill efflunamed newsprint mill in eastern have shown that effluent from ents impair fish reproduction by Canada. The stored samples, pulp and paper mills discharged interacting with neuto nearby waters is linked rotransmitter systems,” with plummeting fish the team writes in its populations, alterations in study. Oregon State Unisex-hormone levels and versity’s Lawrence Curtis physical characteristics of agrees: “[The paper] idensex organs, and other tifies potential new modes changes such as reduced of action of pulp and paegg production. per mill effluent toxicity.” However, the specific However, as Curtis, the mechanisms through authors, and others note, which such damage octhe study has many limitacurs remain unclear. In a tions. The variables that study published in ES&T still need to be tested in(DOI 10.1021/es802552m), clude different types of a team of researchers wood, a range of pulping from Canada and the U.S. and papermaking prosays it has identified sev- Effluent containing neuroactive substances from some pulp cesses around the world, eral rarely explored path- and paper mills is linked with damage to fish in nearby waters. seasonal changes in effluways that may be ent content, and different plausible candidates. taken on various dates, were responses by various fish species. Instead of studying direct endoprocessed from February 1 to In addition, the team’s use of a crine disruption through research May 1, 2007. They used five mesingle exposure concentration on endocrine organs, as many dia, including ethyl acetate, wadoesn’t offer insight on whether have done, the team evaluated ter, and ethanol, to extract the receptor and enzyme reseveral neurochemical pathways, various compounds from the efsponses were affected by either which have essential regulatory fluent samples. receptor destruction or displaceroles in fish reproduction, says Back in the lab, the scientists ment caused by competitive bindVance Trudeau of the University exposed brain tissue from coming of different chemicals to the of Ottawa and the study’s coaumon goldfish to one standard receptors, says Joakim Larsson of thor. These pathways include reconcentration of each extract Sweden’s Goteborg University. ceptors, which can change the sample of 0.5 milligrams per Larsson also cautions that the function of the cells to which they milliliter. They used a fixed conin vitro methods used in the are attached, and enzymes, which centration to make direct comstudy don’t reflect realistic enviact as catalysts for various cellular parisons between all the ronmental exposures. and body functions. The four reextracts, which had highly variDespite these limitations, “this ceptors and four enzymes that the able yields of many substances. type of biomarker will be really researchers selected had been useful,” says Maria Sepulveda of identified in other studiessa The team evaluated 80 posPurdue University. dozen of which they cite in their sible combinations of receptors, papersas important reproductive enzymes, extraction media, and — ROBERT WEINHOLD neurotransmission components. effluent types. Of the 80 possible The receptors included dopacombinations, 32 showed a sigmine-2, γ-aminobutyric acid nificant difference compared (GABA), N-methyl-D-aspartic acid, with controls, increasing or decreasing receptor binding or enand muscarinic acetylcholine zyme activity by anywhere from (mACh). The enzymes included -75.1% to 188.9%. monoamine oxidase, GABAESTORMIZ, COURTESY OF WIKIMEDIA COMMONS
A new pulp fact?
1242 9 ENVIRONMENTAL SCIENCE & TECHNOLOGY / March 1, 2009
10.1021/es803564j
2009 American Chemical Society
Published on Web 01/14/2009
