Canadian federal scientists say the common additive to industrial and household detergents and sprays seems to be related to the troubles of East Coast salmon stocks. The question is, where else are these chemicals causing problems?
by Miranda Holmes
Recent Department of Fisheries and Oceans research suggests that nonylphenols (one of the breakdown products of the family of chemicals known as alkylphenol ethoxylates or APEs) may be playing a role in the failure of salmon stocks to return to many of Canada's East Coast rivers.
Regular Watershed Sentinel readers will remember hearing about nonylphenols (NPs) before [See "Does Your Shampoo APE Hormones? Dec 98/Jan. 99] These endocrine-disrupting chemicals have been shown to cause human breast cancer cells to replicate and "gender bending" in fish. APEs are used primarily as a sudsing agent in industrial and domestic detergents and in some shampoos and other personal care products.
NPs are also used in some pesticides, including one formula of Matacil, widely used against the spruce budworm in Nova Scotia, New Brunswick and Newfoundland during the 1970s and 80s.
"Salmon have to change from freshwater smolts to saltwater juveniles and there's a whole process of development that could be influenced by changes in hormones," explains New Brunswick-based DFO scientist Wayne Fairchild, who led the research.
"What if the chemical exposure did something to influence juvenile salmon just as they were going out to sea? When we did the study, to our surprise, all the data that we had between forest spray exposures and salmon populations started lining up."
In the spring of 1998, Fairchild, along with team members from the University of New Brunswick and the National Water Research Institute, collected spray maps of the Canadian Wildlife Service, annual reports of the Forest Pest Control Forum and other provincial monitoring documents.
It All Lined Up
They found a clear linear pattern in one river between the amount of NP-containing Matacil sprayed in 1977 and decreased numbers of salmon returning two years later. There was also an unusually heavy salmon smolt mortality that year, at its highest where that spray was used. Blue backed herring, which have a similar fresh to salt water life pattern, also dropped noticeably in numbers two years later.
Budworm spraying coincides with the final stages of smolt development. Tests conducted last year by Fairchild's team found that NPs seemed to have no effect on the fish over a short period. However, a few weeks later some of the test fish began losing weight and shortly afterwards died.
Fairchild hopes to learn more if funding can be secured for a tagging program which will monitor the return of salmon reared in a clean environment as well as salmon which have been exposed to NPs in rivers.
While numerous factors (including habitat destruction, over fishing and global warming) are undoubtedly impacting on the health of many salmon stocks, scientists feel the importance of harm done at this crucial stage of development cannot be underestimated.
Despite the fact that this particular pesticide has not been used for over a decade, the levels of NPs which were found in forest streams after spraying can still be found in the effluents of sewage treatment plants and large industries. In these cases, the NPs are present as the breakdown products of nonylphenol ethoxylates (NPEs), the most common alkylphenol ethoxylate, used in large quantities for pulp and paper, textile and leather manufacturing, as well as petroleum production and those detergents and shampoos.
Meanwhile, on the West Coast
Research at the DFO's Institute of Ocean Sciences (IOS) on Vancouver Island has been focussing on NPEs, primarily in sediments found near sewage treatment plants.
IOS scientist Rob MacDonald is part of a team who've developed a new method for analyzing NPEs.
Conventional wisdom held that the ethoxylate chain of NPEs broke down fairly quickly, releasing endocrine-disrupting NPs into the environment. MacDonald has discovered that this isn't necessarily the case. In Georgia Strait sediment samples contain a mixture of both broken down and intact NPEs, suggesting that those which make it through the sewage treatment system and into the sediment do not break down. (Sediment near Vancouver's primary-treatment sewage plant on Iona Island contained significant levels of both. There are no plans to upgrade treatment at the plant, which could be the single largest cause of pollution in Georgia Strait.)
While this is a fascinating discovery for chemists, MacDonald freely admits: "If the ethoxylates stick to the NPs, do they have an effect on aquatic species? We don't know."
There are a tremendous number of unknowns. Data about the amounts of NPEs going into sewage treatment plants is virtually non-existent, so there is no way to even guess how much ends up in settling ponds to turn into sludge, which is eventually buried or – in the case of some North American plants – sold off as fertilizer to farmers.
Nor is there any analysis currently being done of sediments near pulp mills, despite the fact that this industry uses one third of the NPEs sold in Canada, although MacDonald plans to reanalyze an old sediment core taken off Port Melon.
Back on the East Coast, Fairchild and his team are pursuing funding to look at the effects of current effluents, including pulp and paper mills, over the next three years. They plan to be in the field this summer working with Atlantic salmon. It's a start.
What's Your Poison?
The next time you have a bottle of French wine that tastes "corked" (a mouldy, dank smell and taste usually attributed to corks not properly sanitized by producers), don't assume the stopper's at fault.
Research conducted by the French publication L'Express and reported recently in the New York Times indicates that during the 1980s and early 1990s, trace quantities of the pesticide chlorophenol found their way into wines from the country's major wine producing regions.
The fault lay not with the corks, but with the building boom which during that period saw many wine makers constructing new storage buildings and cellars, in many cases using wood which had been treated with chlorophenol, the fumes of which seeped into wooden barrels and eventually into the wine itself.
Although the problem first surfaced in a 1982 batch of Roederer Cristal champagne, it wasn't until 1991 that Pascal Chatonnet, a research chemist at the University of Bordeaux and an employee of Seguin & Moreau, a well-known barrel-making firm, discovered the cause.
The French media may have ignored his findings, but wine makers did not. Since then, storage buildings and cellars have been ripped out and replaced. In 1994 the French government banned the use of substances that contain high concentrations of chlorophenol.
Authorities maintain that older, contaminated bottles are perfectly safe. This, of course, may be based on the fact that the wine tastes so awful no one would actually drink it.
[From WS February/March 1999]