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Highlights
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Taking Toxins to TaskAlthough we chide ourselves for polluting the lakes and rivers that provide our drinking water, nature occasionally does much the same thing. Given the right conditions, and often exacerbated by man's pollution, large numbers of microscopic cyanobacteria can thrive at the water's surface, "blooming" to an extent that turns them into a major hazard should they release chemicals that are toxic to us. Also known as blue-green algae, cyanobacteria represent some of the very first life forms that occupied our planet, dating back more than three billion years. Nevertheless, these venerable organisms can cause trouble for more recent life forms, including us, should we encounter them in the form of harmless-looking pond scum on a summer's day. Cattle and dogs can die within minutes of eating this chunky vegetable matter, if it also happens to contain the toxins capable of damaging vital organs like the kidneys and liver. People have likewise been poisoned when they consumed contaminated water. A recent spectacular case in Brazil led to the deaths of 52 dialysis patients when cyanotoxins entered their bodies through the tap water being used to help cleanse their blood. Regulatory officials need to know when a toxin has entered a water supply, and they want to know fast. Not only do they need to identify what sort of agent they might be dealing with, it is imperative to make accurate measurements of just how much of it is present, so that the extent of the hazard can be assessed. They must also know what water treatment methods are effective at removing such contaminants.
Unfortunately, some of the world's most threatening natural toxins present significant challenges to current chemical analysis methods, the most serious issue being the lack of accurate calibration standards for toxins. Michael Quilliam knows this all too well, having spent most of his career developing analytical techniques and standards to overcome these problems in the marine toxin field. In April, the chemist and his colleagues in the Certified Reference Materials Program (CRMP) at NRC's Institute for Marine Biosciences in Halifax added one more accomplishment to a growing list, as they launched their latest product into worldwide distribution. They were launching the first Certified Reference Material (CRM) for a cyanotoxin, along with the prospect of enabling public health authorities to respond much more effectively to this water-borne menace. CRMs are chemical solutions or samples with accurately known levels of toxins that can be used to calibrate laboratory instruments that analyze samples collected in the field. For example, liquid chromatography-mass spectrometry (LC-MS) is now the most commonly used instrument in the toxins field, since its first application to toxins in 1989 by the NRC group. CRMs allow the rapid establishment of LC-MS methods and on-going calibration as each batch of samples is analyzed. "Many toxins cannot be purchased through commercial sources, and even if they are available, they're not very pure, which can lead to the preparation of inaccurate calibration solutions," says Quilliam, adding that these complex organic compounds may also be unstable if dissolved in the wrong solvent. To make matters worse, companies that do market toxins can charge as much as $5,000 a milligram, forcing cost-conscious analysts to work with extremely small amounts that are difficult to weigh and more susceptible to contamination. Quilliam first began taking up the challenge surrounding cyanobacterial toxin CRMs several years ago, when the issue was discussed at an international conference in Norway. The conference attendees voted that their number one priority was the production of Certified Reference Materials. During and after the meeting, Quilliam was able to establish collaborative projects with counterparts in Australia, New Zealand, and Finland to work on CRMs for a number of different cyanotoxins. The CRM just released is for the toxin, cylindrospermopsin, which is increasingly being found in drinking water supplies around the world. Another cyanotoxin CRM expected to be released later this year is for anatoxin-a, a toxin often implicated in animal deaths. Later this year, his group will be working on CRMs for a set of other cyanotoxins, called microcystins, the toxins that caused the deaths in Brazil. Scientists from Finland and New Zealand will come to Halifax to work in the NRC-IMB laboratory on this project. "I enjoy solving problems, and solving them very efficiently and quickly," says Quilliam. "Analytical technologies are the key to that." That outlook has served Quilliam and the NRC Institute for Marine Biosciences well, starting soon after he began working there in 1987. That was when a mysterious shellfish-poisoning incident hospitalized some 150 people, afflicting some with memory loss, symptoms akin to Alzheimer's disease. The syndrome is now known as Amnesic Shellfish Poisoning. Working around the clock for days on end, the NRC team identified the cause as a toxin called domoic acid. Soon after that, an analytical method and calibration standards were prepared and implemented into the Canadian shellfish-monitoring program. After that crisis had passed, the NRC team decided to prioritize the development of analytical methods and the preparation of CRMs for shellfish toxins. Within a year, the group had created CRMs for domoic acid, the first of a series of marine toxin CRMs that have given the NRC a global reputation in this field.
"We're the only ones in the world distributing CRMs for marine toxins," he observes, noting that these resources have become vitally important for scientists anywhere who might be struggling to confront a poisoning event like the one he first faced almost 20 years ago.
And Quilliam adds that as these efforts expand to encompass freshwater toxins, other opportunities could also arise. Eventually, these CRMs could facilitate the development of convenient kits that could be carried into isolated settings, where they could simply be dipped in water to determine the presence of cyanotoxins. "It will open up possibilities for rapid testing technologies, which we could develop here and commercialize," he says. Such kits represent an important commercial opportunity, one with its roots in the National Research Council. More importantly, by tackling the ongoing challenges of contamination, this technology is helping ensure the safety of Canada's drinking water. Recommended Links:
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